Insects

14 pages, 2429 KiB

Open AccessArticle

Genome-Wide Identification and Expression Pattern of Cytochrome P450 Genes in the Social Aphid Pseudoregma bambucicola

by Jianjun Lu, Hui Zhang, Qing Wang and Xiaolei Huang

Insects 2023, 14(2), 212; https://doi.org/10.3390/insects14020212 - 20 Feb 2023

Viewed by 1639

Abstract

Cytochrome P450 monooxygenases (P450s) have a variety of functions, including involvement in the metabolism of exogenous substances and the synthesis and degradation of endogenous substances, which are important for the growth and development of insects. Pseudoregma bambucicola is a social aphid that produces [...] Read more.

Cytochrome P450 monooxygenases (P450s) have a variety of functions, including involvement in the metabolism of exogenous substances and the synthesis and degradation of endogenous substances, which are important for the growth and development of insects. Pseudoregma bambucicola is a social aphid that produces genetically identical but morphologically and behaviorally distinct first-instar soldiers and normal nymphs within colonies. In this study, we identified 43 P450 genes based on P. bambucicola genome data. Phylogenetic analysis showed that these genes were classified into 4 clans, 13 families, and 23 subfamilies. The CYP3 and CYP4 clans had a somewhat decreased number of genes. In addition, differential gene expression analysis based on transcriptome data showed that several P450 genes, including CYP18A1, CYP4G332, and CYP4G333, showed higher expression levels in soldiers compared to normal nymphs and adult aphids. These genes may be candidates for causing epidermal hardening and developmental arrest in soldiers. This study provides valuable data and lays the foundation for the study of functions of P450 genes in the social aphid P. bambucicola. Full article

(This article belongs to the Special Issue Systematics, Ecology and Evolution of Aphids)

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23 pages, 4869 KiB

Open AccessArticle

Preliminary Evidence That Fiji Water Has Protective Effects against Aluminum Toxicity in Honey Bees (Apis mellifera)

by Kiri Li N. Stauch, Ana M. Chicas-Mosier and Charles I. Abramson

Insects 2023, 14(2), 211; https://doi.org/10.3390/insects14020211 - 20 Feb 2023

Viewed by 3588

Abstract

Researchers have determined that bioavailable aluminum chloride (AlCl3) may affect honey bee behavior (e.g., foraging patterns and locomotion) and physiology (e.g., abdominal spasms). The purpose of these experiments was to determine if Fiji water reduces the impacts of AlCl3 toxicity in bees by [...] Read more.

Researchers have determined that bioavailable aluminum chloride (AlCl3) may affect honey bee behavior (e.g., foraging patterns and locomotion) and physiology (e.g., abdominal spasms). The purpose of these experiments was to determine if Fiji water reduces the impacts of AlCl3 toxicity in bees by measuring circadian rhythmicity (number of times bees crossed the centerline during the day and night), average daily activity (average number of times bees crossed the centerline per day), and mortality rates (average number of days survived) using an automated monitor apparatus. Overall, the AlCl3 before and after Fiji groups had significantly higher average daily activity and rhythmicity rates compared to their respective AlCl3 before and after deionized water (DI) groups. One of the AlCl3 before DI groups exhibited no difference in rhythmicity rates compared to its respective AlCl3 after Fiji group. Overall, these results suggest that Fiji water might exert protective effects against AlCl3. The AlCl3 groups paired with Fiji water had higher activity and rhythmicity levels compared to the AlCl3 groups paired with DI. It is important for researchers to continue to study aluminum and possible preventatives for aluminum uptake. Full article

(This article belongs to the Section Insect Societies and Sociality)

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18 pages, 4807 KiB

Open AccessArticle

Effects of Species Invasion and Inundation on the Collembola Community in Coastal Mudflat Wetland from the Perspective of Functional Traits

by Jing-Yang Li, Yun-Xia Gao, Chun-Yang Li, Ya-Li Jin, Si-Qi Yang, Jian-Hong Xia, Yun-Fei Zhang, Yun Bu and Kai Li

Insects 2023, 14(2), 210; https://doi.org/10.3390/insects14020210 - 19 Feb 2023

Cited by 1 | Viewed by 1597

Abstract

The group of soil arthropods known as Collembola is characterized by its abundance and sensitivity to environmental changes. They are ideal an species for soil indicators. In order to clarify the effects of species invasion and inundation on the Collembola community in coastal [...] Read more.

The group of soil arthropods known as Collembola is characterized by its abundance and sensitivity to environmental changes. They are ideal an species for soil indicators. In order to clarify the effects of species invasion and inundation on the Collembola community in coastal mudflat wetlands, the correlation between the collembolan functional traits and environmental factors was studied in Shanghai Jiuduansha Wetland National Nature Reserve for the first time. Five sample plots, including three vegetations—Spartina alterniflora (an invasive species), Phragmites australis, and Zizania latifolia—were set up following the differences in vegetation types and between high and low tidal flats. Data on the diversity of the Collembolan species and their functional traits were collected and combined with the soil physicochemical properties and vegetation environment factors in different tidal flats. The key findings and conclusions of the study are as follows: a total of 18 species, four families, and three orders make up the obtained Collembola, two species of Proisotoma are dominant species that account for 49.59% and 24.91% of the total, respectively. The maintenance of the species diversity of Collembola is disturbed by the higher conversion efficiency of Spartina alterniflora rather than Phragmites australis with lower organic carbon (C) content and higher total nitrogen (N) content. The primary environmental variables influencing species distribution were the C/N ratio, total N, and bulk soil density. The bulk density of the soil impacts the movement and dispersal of the functional traits. The depth of the soil layer is related to the functional traits of the sensory ability. The analysis of the functional traits and environment is fairly helpful in exploring how species respond to their environment and offers a better explanation for the habitat selection of Collembola. Full article

(This article belongs to the Topic Arthropod Biodiversity: Ecological and Functional Aspects)

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19 pages, 4318 KiB

Open AccessArticle

Mating-Induced Common and Sex-Specific Behavioral, Transcriptional Changes in the Moth Fall Armyworm (Spodoptera frugiperda, Noctuidae, Lepidoptera) in Laboratory

by Ting Wu, Da-Hu Cao, Yu Liu, Hong Yu, Da-Ying Fu, Hui Ye and Jin Xu

Insects 2023, 14(2), 209; https://doi.org/10.3390/insects14020209 - 19 Feb 2023

Cited by 6 | Viewed by 2104

Abstract

The intermediate process between mating and postmating behavioral changes in insects is still poorly known. Here, we studied mating-induced common and sex-specific behavioral and transcriptional changes in both sexes of Spodoptera frugiperda and tested whether the transcriptional changes are linked to postmating behavioral [...] Read more.

The intermediate process between mating and postmating behavioral changes in insects is still poorly known. Here, we studied mating-induced common and sex-specific behavioral and transcriptional changes in both sexes of Spodoptera frugiperda and tested whether the transcriptional changes are linked to postmating behavioral changes in each sex. A behavioral study showed that mating caused a temporary suppression of female calling and male courting behavior, and females did not lay eggs until the next day after the first mating. The significant differences on daily fecundity under the presence of males or not, and the same or novel males, suggest that females may intentionally retain eggs to be fertilized by novel males or to be fertilized competitively by different males. RNA sequencing in females revealed that there are more reproduction related GO (gene ontology) terms and KEGG (Kyoto encyclopedia of genes and genomes) pathways (mainly related to egg and zygote development) enriched to upregulated DEGs (differentially expressed genes) than to downregulated DEGs at 0 and 24 h postmating. In males, however, mating induced DEGs did not enrich any reproduction related terms/pathways, which may be because male reproductive bioinformatics is relatively limited in moths. Mating also induced upregulation on soma maintenance (such as immune activity and stress reaction) related processes in females at 0, 6 and 24 h postmating. In males, mating also induced upregulation on soma maintenance related processes at 0 h postmating, but induced downregulation on these processes at 6 and 24 h postmating. In conclusion, this study demonstrated that mating induced sex-specific postmating behavioral and transcriptional changes in both sexes of S. frugiperda and suggested that the transcriptional changes are correlated with postmating physiological and behavioral changes in each sex. Full article

(This article belongs to the Special Issue Recent Advances in Fall Armyworm Research)

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26 pages, 5607 KiB

Open AccessArticle

Do Patches of Flowering Plants Enhance Insect Pollinators in Apple Orchards?

by Myrto Barda, Filitsa Karamaouna, Vaya Kati and Dionysios Perdikis

Insects 2023, 14(2), 208; https://doi.org/10.3390/insects14020208 - 19 Feb 2023

Cited by 4 | Viewed by 2354

Abstract

Apples depend on insect pollination but intensification of agriculture jeopardizes pollination services in agroecosystems. Concerns about the dependency of crop pollination exclusively on honey bees increase the interest in agricultural practices that safeguard wild pollinators in agroecosystems. The purpose of the study was [...] Read more.

Apples depend on insect pollination but intensification of agriculture jeopardizes pollination services in agroecosystems. Concerns about the dependency of crop pollination exclusively on honey bees increase the interest in agricultural practices that safeguard wild pollinators in agroecosystems. The purpose of the study was to assess the potential of floral resource provision in apple orchards to enhance the conservation of hymenopterous pollinating insects and potentially the pollination service to the crop. For this reason, flowering plant mixtures sown in patches inside apple orchards were tested against wild plant patches. Pollinator taxa recorded on the sown and wild plant patches were honey bees, wild bees (Andrena, Anthophora, Eucera, Halictus, Lasioglossum, Megachilidae on both; Systropha only on wild plants; Bombus, Hylaeus, Sphecodes, Nomada, Xylocopa only on sown mixture), syrphids, bee flies. The most abundant pollinator of apple was A. mellifera but wild bees were also recorded (Andrena, Anthophora, Bombus, Xylocopa, Lasioglossum, Megachilidae). The sown mixture attracted a more diverse taxa of pollinators and in greater numbers compared to the weed flora, but it did not have an effect on pollinators visiting apple flowers. Groundcover management with patches of suitable flowering mixtures can enhance pollinator conservation in apple orchards. Full article

(This article belongs to the Special Issue Practices to Conserve Pollinators and Natural Enemies in Agro-Ecosystems)

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18 pages, 1752 KiB

Open AccessArticle

From the Lab to the Field: Long-Distance Transport of Sterile Aedes Mosquitoes

by Hamidou Maïga, Mame Thierno Bakhoum, Wadaka Mamai, Gorgui Diouf, Nanwintoum Séverin Bimbilé Somda, Thomas Wallner, Claudia Martina, Simran Singh Kotla, Odet Bueno Masso, Hanano Yamada, Bazoumana B. D. Sow, Assane Gueye Fall and Jeremy Bouyer

Insects 2023, 14(2), 207; https://doi.org/10.3390/insects14020207 - 18 Feb 2023

Cited by 3 | Viewed by 2233

Abstract

Pilot programs of the sterile insect technique (SIT) against Aedes aegypti may rely on importing significant and consistent numbers of high-quality sterile males from a distant mass rearing factory. As such, long-distance mass transport of sterile males may contribute to meet this requirement [...] Read more.

Pilot programs of the sterile insect technique (SIT) against Aedes aegypti may rely on importing significant and consistent numbers of high-quality sterile males from a distant mass rearing factory. As such, long-distance mass transport of sterile males may contribute to meet this requirement if their survival and quality are not compromised. This study therefore aimed to develop and assess a novel method for long-distance shipments of sterile male mosquitoes from the laboratory to the field. Different types of mosquito compaction boxes in addition to a simulation of the transport of marked and unmarked sterile males were assessed in terms of survival rates/recovery rates, flight ability and morphological damage to the mosquitoes. The novel mass transport protocol allowed long-distance shipments of sterile male mosquitoes for up to four days with a nonsignificant impact on survival (>90% for 48 h of transport and between 50 and 70% for 96 h depending on the type of mosquito compaction box), flight ability, and damage. In addition, a one-day recovery period for transported mosquitoes post-transport increased the escaping ability of sterile males by more than 20%. This novel system for the long-distance mass transport of mosquitoes may therefore be used to ship sterile males worldwide for journeys of two to four days. This study demonstrated that the protocol can be used for the standard mass transport of marked or unmarked chilled Aedes mosquitoes required for the SIT or other related genetic control programs. Full article

(This article belongs to the Special Issue Mosquito Handling, Transport, Release and Male Trapping Methods)

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13 pages, 1077 KiB

Open AccessArticle

Behavioural and Electrophysiological Response of Anastrepha fraterculus (Diptera: Tephritidae) to a γ-Lactone Synthetic Semiochemical

by Lucía Goane, Beatriz N. Carrizo, María Josefina Ruiz, Guillermo E. Bachmann, Fabian H. Milla, Diego F. Segura, Dan Kuzmich, Spencer Walse and María Teresa Vera

Insects 2023, 14(2), 206; https://doi.org/10.3390/insects14020206 - 18 Feb 2023

Cited by 1 | Viewed by 1759

Abstract

Attractants are a powerful tool for pest management. The lack of specific attractants for the South American fruit fly, Anastrepha fraterculus, a complex of cryptic species of great economic importance in South America, makes it difficult to monitor the pest in the [...] Read more.

Attractants are a powerful tool for pest management. The lack of specific attractants for the South American fruit fly, Anastrepha fraterculus, a complex of cryptic species of great economic importance in South America, makes it difficult to monitor the pest in the field. The γ-lactone male sex and aggregation pheromones of several Anastrepha species, naturally released in a 7:3 epianastrephin to anastrephin ratio, and a structurally related naturally occurring γ-lactone ((±)-trans-tetrahydroactinidiolide) with gem-dimethyl groups (dimethyl) at C(4), were evaluated as potential attractants of this species. Different age and mating conditions of A. fraterculus males and females were evaluated during electroantennography (EAG) and field cage experiments in which polymeric lures were deployed to contain 100 mg of attractant. Epianastrephin and dimethyl were EAG+ for all fly conditions, with epianastrephin eliciting the highest response for both sexes and immature flies showing greater responsiveness than mature flies. In the field cage experiments, immature flies were only attracted to leks; virgin females were attracted to leks, dimethyl, and both epianastrephin-anastrephin formulations (95 and 70 wt.% epianastrephin); mature-mated males were attracted to leks, dimethyl and 70 wt.% epianastrephin; and mature-mated females were only attracted to leks. Our bioassays showed a promising performance of the analog dimethyl since it elicited the same response as epianastrephin, requires fewer steps to synthesize, and contains one less chiral center than the natural pheromones. The attraction to leks was recorded for all mating conditions and ages of flies and suggests that air-borne volatiles of calling males contain cues that could act as sensory traps. The addition of any of these compounds in the synthetic attractants may result in a greater attraction and thus deserves further evaluation. Dose-response experiments will provide additional information to move a step forward and validate the results obtained in open-field conditions. Full article

(This article belongs to the Special Issue Genetics and Ecological Evolution of Dipteran Pest Species)

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15 pages, 2786 KiB

Open AccessArticle

Sphenophorus levis Behavior Studies: Evaluating Insect Attractiveness or Repellency to One Insecticide Treatment and Assessing Nocturnal Insect Activity and Location Pattern

by Pedro Henrique Urach Ferreira and Marcelo da Costa Ferreira

Insects 2023, 14(2), 205; https://doi.org/10.3390/insects14020205 - 18 Feb 2023

Cited by 1 | Viewed by 1964

Abstract

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae). is a difficult to control pest in sugarcane that causes great damage to the subterranean part of the plant. Low insect control is the result of the pesticide application technology adopted but also a consequence of the [...] Read more.

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae). is a difficult to control pest in sugarcane that causes great damage to the subterranean part of the plant. Low insect control is the result of the pesticide application technology adopted but also a consequence of the lack of studies regarding the pest’s behavior. This research aimed to examine the attractiveness and repellency of one labelled insecticide dose to S. levis adults and to evaluate the activity and location behavior of S. levis adults under hourly observations over 24 h. Repellency and attractiveness studies were conducted in free-choice tests with treated soil with an insecticide product composed of lambda-cyhalothrin + thiamethoxam active ingredients and untreated soil. Insect activity and location behavior studies were assessed by conducting hourly observations of S. levis adults in containers with soil and sugarcane plant. The results indicate that S. levis adults are not repelled nor attracted to soil treated with the labelled dose of lambda-cyhalothrin + thiamethoxam in sugarcane. Additionally, insects presented nocturnal behavior for most activities (walking, digging and mating) starting at 6:00 p.m. until 2:00 a.m. An average of 21% of insects were out of the soil at night while the majority, 79%, remained inside the soil. During the day, most insects, 95%, remained hidden in the soil. Exposed insects were primarily located on the soil surface. According to these results, nocturnal insecticide applications may improve S. levis adult control due to greater insect activity and exposure at night. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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19 pages, 723 KiB

Open AccessArticle

Bioconversion of Different Waste Streams of Animal and Vegetal Origin and Manure by Black Soldier Fly Larvae Hermetia illucens L. (Diptera: Stratiomyidae)

by Somaya Naser El Deen, Klaas van Rozen, Hellen Elissen, Piet van Wikselaar, Istvan Fodor, Rommie van der Weide, Elise Federica Hoek-van den Hil, Arya Rezaei Far and Teun Veldkamp

Insects 2023, 14(2), 204; https://doi.org/10.3390/insects14020204 - 17 Feb 2023

Cited by 12 | Viewed by 3411

Abstract

Black soldier fly larvae (BSFL) are considered a commercially viable solution for global organic waste problems. The objective of this study was to assess the feasibility of rearing BSFL on a wide range of low-value waste streams and its potential to transform them [...] Read more.

Black soldier fly larvae (BSFL) are considered a commercially viable solution for global organic waste problems. The objective of this study was to assess the feasibility of rearing BSFL on a wide range of low-value waste streams and its potential to transform them into high-quality animal feed and fertilizer. Six waste streams of different origins were selected and each tested in triplicate. Several parameters were analysed: growth performance, waste reduction index (WRI), conversion efficiency (ECI) and larval composition. Frass composition was also analysed. Larvae reared on fast food waste (FFW) had the highest ECI and WRI and the lowest values when reared on pig manure slurry mixed with silage grass (PMLSG) and slaughter waste (SW). The highest protein content was found for larvae reared on mushroom stems (MS) although this substrate had the lowest protein content. Moreover, the frass nutritional profile was proportionally related to the substrate’s nutritional profile: the protein-rich substrate (SW) resulted in protein-rich frass and the low-protein substrate (MS) resulted in protein-poor frass. The same was true for the lipid content. In conclusion, this study showed that BSFL can be successfully reared on a wide range of waste streams that can affect the larval and frass chemical compositions. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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16 pages, 1911 KiB

Open AccessArticle

Higher Essential Amino Acid and Crude Protein Contents in Pollen Accelerate the Oviposition and Colony Foundation of Bombus breviceps (Hymenoptera: Apidae)

by Chang-Shi Ren, Zhi-Min Chang, Lei Han, Xiang-Sheng Chen and Jian-Kun Long

Insects 2023, 14(2), 203; https://doi.org/10.3390/insects14020203 - 17 Feb 2023

Cited by 2 | Viewed by 1387

Abstract

Pollen is an important source of nutrition for bumblebees to survive, reproduce, and raise their offspring. To explore the nutritional requirements for the egg laying and hatching of queenright Bombus breviceps colonies, camellia pollen, oilseed rape pollen, apricot pollen, and mixtures of two [...] Read more.

Pollen is an important source of nutrition for bumblebees to survive, reproduce, and raise their offspring. To explore the nutritional requirements for the egg laying and hatching of queenright Bombus breviceps colonies, camellia pollen, oilseed rape pollen, apricot pollen, and mixtures of two or three types of pollen in equal proportions were used to feed the queens in this study. The results showed that the camellia pollen with a higher essential amino acid content was superior to the pollen with a lower essential amino acid content in the initial egg-laying time (p < 0.05), egg number (p < 0.05), larval ejection (p < 0.01), time of first worker emergence (p < 0.05), and the average weight of workers in the first batch (p < 0.01). It took less time for colonies under the camellia pollen and camellia–oilseed rape–apricot pollen mix treatments, both with a higher crude protein content, to reach ten workers in the colony (p < 0.01). On the contrary, the queens fed apricot pollen never laid an egg, and larvae fed oilseed rape pollen were all ejected—both pollens with a lower essential amino acid content. The results emphasize that the diet should be rationally allocated to meet the nutritional needs of local bumblebees at various stages when guiding them to lay eggs, hatch, and develop a colony. Full article

(This article belongs to the Special Issue Advances in Insect Diet and Rearing Methodology (Volume II))

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21 pages, 4836 KiB

Open AccessArticle

The Plastic Larval Body Color of the Pale Grass Blue Butterfly Zizeeria maha (Lepidoptera: Lycaenidae) in Response to the Host Plant Color: The Maternal Effect on Crypsis

by Ai Yoshida, Shintaro Yabu and Joji M. Otaki

Insects 2023, 14(2), 202; https://doi.org/10.3390/insects14020202 - 17 Feb 2023

Cited by 1 | Viewed by 1865

Abstract

Many lepidopteran larvae show body color polyphenism, and their colors may be cryptic on the host plant leaves. To elucidate the effect of the host plant color on the plastic larval body color, we focused on the lycaenid butterfly Zizeeria maha, which [...] Read more.

Many lepidopteran larvae show body color polyphenism, and their colors may be cryptic on the host plant leaves. To elucidate the effect of the host plant color on the plastic larval body color, we focused on the lycaenid butterfly Zizeeria maha, which shows various larval body colors ranging from green to red, even within a sibling group. We showed that oviposition was normally performed on both green and red leaves, despite a green preference and the fact that the larvae grew equally by consuming either green or red leaves. The number of red larvae decreased from the second instar stage to the fourth instar stage, demonstrating a stage-dependent variation. When the larvae were fed either green or red leaves across multiple generations of the lineages, the red larvae were significantly more abundant in the red leaf lineage than in the green leaf lineage. Moreover, the red-fed siblings showed a significantly higher red larval frequency than the green-fed siblings in the red-leaf lineage but not in the green-leaf lineage. These results suggest that, in this butterfly species, the plastic larval body color for crypsis may be affected not only by the color of the leaves that the larvae consume (single-generation effect) but also by the color of the leaves that their mothers consume (maternal effect), in addition to a stage-dependent color variation. Full article

(This article belongs to the Special Issue Phenotypic Plasticity of Insects)

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22 pages, 2015 KiB

Open AccessReview

Molecular Genetic Basis of Lab- and Field-Selected Bt Resistance in Pink Bollworm

by Jeffrey A. Fabrick, Xianchun Li, Yves Carrière and Bruce E. Tabashnik

Insects 2023, 14(2), 201; https://doi.org/10.3390/insects14020201 - 17 Feb 2023

Cited by 13 | Viewed by 2930

Abstract

Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) control some important insect pests. However, evolution of resistance by pests reduces the efficacy of Bt crops. Here we review resistance to Bt cotton in the pink bollworm, Pectinophora gossypiella, one [...] Read more.

Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) control some important insect pests. However, evolution of resistance by pests reduces the efficacy of Bt crops. Here we review resistance to Bt cotton in the pink bollworm, Pectinophora gossypiella, one of the world’s most damaging pests of cotton. Field outcomes with Bt cotton and pink bollworm during the past quarter century differ markedly among the world’s top three cotton-producing countries: practical resistance in India, sustained susceptibility in China, and eradication of this invasive lepidopteran pest from the United States achieved with Bt cotton and other tactics. We compared the molecular genetic basis of pink bollworm resistance between lab-selected strains from the U.S. and China and field-selected populations from India for two Bt proteins (Cry1Ac and Cry2Ab) produced in widely adopted Bt cotton. Both lab- and field-selected resistance are associated with mutations affecting the cadherin protein PgCad1 for Cry1Ac and the ATP-binding cassette transporter protein PgABCA2 for Cry2Ab. The results imply lab selection is useful for identifying genes important in field-evolved resistance to Bt crops, but not necessarily the specific mutations in those genes. The results also suggest that differences in management practices, rather than genetic constraints, caused the strikingly different outcomes among countries. Full article

(This article belongs to the Special Issue Resistance of Pests to Insecticidal Proteins from Bacillus thuringiensis (Bt))

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13 pages, 1588 KiB

Open AccessArticle

Cut to Disarm Plant Defence: A Unique Oviposition Behaviour in Rhynchites foveipennis (Coleoptera: Attelabidae)

by Zhi-Ying Zhang, Wei Li, Qi-Chao Huang, Liu Yang, Xiao-Lan Chen, Ru-Di Xiao, Cindy Q. Tang and Shao-Ji Hu

Insects 2023, 14(2), 200; https://doi.org/10.3390/insects14020200 - 17 Feb 2023

Viewed by 1351

Abstract

Female weevils of the family Attelabidae (Coleoptera: Curculionoidea) possess a unique behaviour of partially cutting the branches connecting egg-bearing organs of their host plants during oviposition. However, the consequence of such behaviour remains unclear. Using Rhynchites foveipennis and its host pear (Pyrus [...] Read more.

Female weevils of the family Attelabidae (Coleoptera: Curculionoidea) possess a unique behaviour of partially cutting the branches connecting egg-bearing organs of their host plants during oviposition. However, the consequence of such behaviour remains unclear. Using Rhynchites foveipennis and its host pear (Pyrus pyrifolia), the present study tested the hypothesis that the oviposition behaviour could disarm the host plants’ defence. We compared the survival rates, growth rates, and performance of eggs and larvae under two conditions: (1) the fruit stems were naturally damaged by the females before and after oviposition, and (2) the fruit stems were artificially protected from the females. When fruit stems were protected from female damage, the survival rates of eggs and larvae were only 21.3–32.6%, respectively; and the larval weight was 3.2–4.1 mg 30 days after laying eggs. When the fruit stems were damaged, the survival rates of eggs and larvae reached 86.1–94.0%, respectively; and the larval weight reached 73.0–74.9 mg 30 days after laying eggs. The contents of tannin and flavonoids in the pears did not change significantly along with the oviposition and larval feeding, but weevil eggs were crushed and killed by the callus in the pears. Once the stunted larvae in branch-growing pears were moved into the picked-off ones, the growth and development recovered. The findings indicate that the oviposition behaviour can significantly increase the survival of the offspring. Our study suggested that the oviposition behaviour of attelabid weevils is a strategy to overcome plant defence. Full article

(This article belongs to the Section Insect Behavior and Pathology)

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10 pages, 1038 KiB

Open AccessCommunication

Thermal Oviposition Performance of the Ladybird Stethorus gilvifrons Preying on Two-Spotted Spider Mites

by Maryam Jafari, Hossein Ranjbar Aghdam, Abbas Ali Zamani, Shila Goldasteh, Ebrahim Soleyman-Nejadian and Peter Schausberger

Insects 2023, 14(2), 199; https://doi.org/10.3390/insects14020199 - 16 Feb 2023

Cited by 2 | Viewed by 1442

Abstract

The ladybird, Stethorus gilvifrons (Mulsant) (Coleoptera: Coccinellidae), is an important predator of two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae), in southeastern Europe and western and southwestern Asia, such as Iran, India, and Turkey. To enhance forecasting the occurrence and performance of this [...] Read more.

The ladybird, Stethorus gilvifrons (Mulsant) (Coleoptera: Coccinellidae), is an important predator of two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae), in southeastern Europe and western and southwestern Asia, such as Iran, India, and Turkey. To enhance forecasting the occurrence and performance of this predator in natural control and improve its usage in biological control, we evaluated and compared four non-linear oviposition models, i.e., Enkegaard, Analytis, Bieri-1, and Bieri-2. The models were validated by using data of age-specific fecundity of female S. gilvifrons at six constant temperatures (15, 20, 25, 27, 30, and 34 °C). All four models provided good fit quality to age-dependent oviposition at 15 to 30 °C (R² 0.67 to 0.94; R²_adj 0.63 to 0.94) but had a poor fit at 34 °C (R² 0.33 to 0.40; R²_adj 0.17 to 0.34). Within temperatures, the best performing models were Bieri-1 (R²), Bieri-2 (R²_adj), and Analytis (RSS) at 15 °C, Bieri-1 at 27 °C, and Analytis at 20, 25, and 30 °C. Analytis was the best suited model across the wide temperature range tested (from 15 to 30 °C). The models presented here allow for prediction of the population dynamics of S. gilvifrons in field and greenhouse crops in temperate and subtropical climates. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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11 pages, 1831 KiB

Open AccessArticle

Influence of Soldiers on Exploratory Foraging Behavior in the Formosan Subterranean Termite, Coptotermes formosanus (Blattodea: Rhinotermitidae)

by Joseph McCarthy, Arjun Khadka, Hasim Hakanoglu and Qian Sun

Insects 2023, 14(2), 198; https://doi.org/10.3390/insects14020198 - 16 Feb 2023

Cited by 2 | Viewed by 1561

Abstract

Termites are eusocial insects that live in organized colonies consisting of reproductives, workers, and soldiers. Soldiers are specialized for defense but are expensive to maintain, as they are incapable of husbandry and must be fed and groomed by workers. The soldiers of several [...] Read more.

Termites are eusocial insects that live in organized colonies consisting of reproductives, workers, and soldiers. Soldiers are specialized for defense but are expensive to maintain, as they are incapable of husbandry and must be fed and groomed by workers. The soldiers of several species influence foraging behavior by acting as scouts that initiate foraging or by mediating worker behavioral plasticity during food exploration. These behaviors imply that soldiers may play a keystone role in termite colony function, apart from defense. Subterranean termite workers tunnel through soil in search of food while accompanied by varying proportions of soldiers, depending on the species and colony conditions. Previous studies have shown that soldiers accelerate worker exploratory tunneling behavior in two Reticulitermes species, the colonies of which contain fewer than 2% soldiers. This effect, however, is unknown in other subterranean species with different soldier proportions. In this study, we examined the influence of soldiers on exploratory foraging behavior in the Formosan subterranean termite, Coptotermes formosanus Shiraki, which is an economically devastating invasive species that maintains a relatively high soldier proportion (about 10%). When 100 foraging workers were grouped with 0, 2, 10, or 30 soldiers in two-dimensional foraging arenas, we found no significant effect of soldiers on the tunnel length, branch pattern, food source interception, or food collected within 96 h. These results suggest that C. formosanus colonies maintain food exploration efficiency regardless of soldier proportion variation. Full article

(This article belongs to the Collection Advance in Biology and Management of Termites—In Memory of Professor Yoshimura)

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12 pages, 2047 KiB

Open AccessArticle

The Transcriptomic Response of the Boll Weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), following Exposure to the Organophosphate Insecticide Malathion

by Lindsey C. Perkin, Zachary P. Cohen, Jason W. Carlson and Charles P.-C. Suh

Insects 2023, 14(2), 197; https://doi.org/10.3390/insects14020197 - 16 Feb 2023

Cited by 1 | Viewed by 1718

Abstract

Insecticide tolerance and resistance have evolved countless times in insect systems. Molecular drivers of resistance include mutations in the insecticide target site and/or gene duplication, and increased gene expression of detoxification enzymes. The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a [...] Read more.

Insecticide tolerance and resistance have evolved countless times in insect systems. Molecular drivers of resistance include mutations in the insecticide target site and/or gene duplication, and increased gene expression of detoxification enzymes. The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a pest of commercial cotton and has developed resistance in the field to several insecticides; however, the current organophosphate insecticide, malathion, used by USA eradication programs remains effective despite its long-term use. Here, we present findings from an RNA-seq experiment documenting gene expression post-exposure to field-relevant concentrations of malathion, which was used to provide insight on the boll weevil’s continued susceptibility to this insecticide. Additionally, we incorporated a large collection of boll weevil whole-genome resequencing data from nearly 200 individuals collected from three geographically distinct areas to determine SNP allele frequency of the malathion target site, as a proxy for directional selection in response to malathion exposure. No evidence was found in the gene expression data or SNP data consistent with a mechanism of enhanced tolerance or resistance adaptation to malathion in the boll weevil. Although this suggests continued effectiveness of malathion in the field, we identified important temporal and qualitative differences in gene expression between weevils exposed to two different concentrations of malathion. We also identified several tandem isoforms of the detoxifying esterase B1 and glutathione S-transferases, which are putatively associated with organophosphate resistance. Full article

(This article belongs to the Special Issue Management of True Weevil (Curculionidae) Pests and Beneficial Species)

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0 pages, 1331 KiB

Open AccessReview

Biology, Ecology and Management of Tephritid Fruit Flies in China: A Review

by Yuxin He, Yijuan Xu and Xiao Chen

Insects 2023, 14(2), 196; https://doi.org/10.3390/insects14020196 - 16 Feb 2023

Cited by 8 | Viewed by 3082 | Correction

Abstract

Tephritid fruit flies are notoriously known for causing immense economic losses due to their infestation of many types of commercial fruits and vegetables in China. These flies are expanding, causing serious damage, and we summarized references from the last three decades regarding biological [...] Read more.

Tephritid fruit flies are notoriously known for causing immense economic losses due to their infestation of many types of commercial fruits and vegetables in China. These flies are expanding, causing serious damage, and we summarized references from the last three decades regarding biological parameters, ecological performance and integrated pest management. There are 10 species of tephritid fruit flies mentioned at a relatively high frequency in China, and a detailed description and discussion in this comprehensive review were provided through contrast and condensation, including economics, distribution, identification, hosts, damage, life history, oviposition preference, interspecific competition and integrated management, in anticipation of providing effective strategies or bases for the subsequent development of new research areas and improvement of integrated management systems. Full article

(This article belongs to the Special Issue Tephritid Fruit Flies (Diptera: Tephritidae): Biology, Ecology, and Integrated Management)

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12 pages, 5795 KiB

Open AccessCommunication

Parthenogenetic Reproduction in Strumigenys Ants: An Update

by Chu Wang, Ping-Jui Sung, Chung-Chi Lin, Fuminori Ito and Johan Billen

Insects 2023, 14(2), 195; https://doi.org/10.3390/insects14020195 - 16 Feb 2023

Cited by 1 | Viewed by 1834

Abstract

Parthenogenetic reproduction is a common feature for social Hymenoptera, as males typically develop from unfertilized eggs (arrhenotoky). Production of female offspring without the involvement of sperm (thelytoky) also exists but is rather exceptional as it has been reported for only 16 ant species [...] Read more.

Parthenogenetic reproduction is a common feature for social Hymenoptera, as males typically develop from unfertilized eggs (arrhenotoky). Production of female offspring without the involvement of sperm (thelytoky) also exists but is rather exceptional as it has been reported for only 16 ant species so far. Three of these belong to the genus Strumigenys: S. hexamera, S. membranifera and S. rogeri. Our observations on the reproductive biology in various Oriental Strumigenys species extends this list of thelytokous ants with three more species: S. emmae, S. liukueiensis and S. solifontis. Of these six thelotykous species, S. emmae, S. membranifera and S. rogeri are known as tramp species. Reproduction without the need to fertilize eggs no doubt offers these species a considerable advantage when establishing colonies in new environments. Published histological data on S. hexamera and S. membranifera already showed that the queens possess a functional spermatheca. We now provide evidence that this is also the case for the four other thelytokous Strumigenys species. Retaining a functional spermatheca and reproductive system may keep the queens ready for the exceptional event of mating and hence increase genetic variability, as males do occur very rarely. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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17 pages, 1378 KiB

Open AccessReview

Dynamic Roles of Insect Carboxyl/Cholinesterases in Chemical Adaptation

by Casey Cruse, Timothy Walter Moural and Fang Zhu

Insects 2023, 14(2), 194; https://doi.org/10.3390/insects14020194 - 16 Feb 2023

Cited by 14 | Viewed by 2781

Abstract

Insects have evolved several intricate defense mechanisms to adapt to their chemical environment. Due to their versatile capabilities in hydrolytic biotransformation, insect carboxyl/cholinesterases (CCEs) play vital roles in the development of pesticide resistance, facilitating the adaptation of insects to their host plants, and [...] Read more.

Insects have evolved several intricate defense mechanisms to adapt to their chemical environment. Due to their versatile capabilities in hydrolytic biotransformation, insect carboxyl/cholinesterases (CCEs) play vital roles in the development of pesticide resistance, facilitating the adaptation of insects to their host plants, and manipulating insect behaviors through the olfaction system. CCEs confer insecticide resistance through the mechanisms of qualitative or quantitative changes of CCE-mediated enhanced metabolism or target-site insensitivity, and may contribute to the host plant adaptation. CCEs represent the first odorant-degrading enzymes (ODEs) discovered to degrade insect pheromones and plant odors and remain the most promising ODE candidates. Here, we summarize insect CCE classification, currently characterized insect CCE protein structure characteristics, and the dynamic roles of insect CCEs in chemical adaptation. Full article

(This article belongs to the Special Issue The Evolution of Pesticide Resistance)

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15 pages, 2135 KiB

Open AccessArticle

Four-Year Overview of Winter Colony Losses in Greece: Citizen Science Evidence That Transitioning to Organic Beekeeping Practices Reduces Colony Losses

by Evangelia Kagiali, Maria Kokoli, Philippos Vardakas, Georgios Goras, Fani Hatjina and Solenn Patalano

Insects 2023, 14(2), 193; https://doi.org/10.3390/insects14020193 - 15 Feb 2023

Cited by 2 | Viewed by 2455

Abstract

The honey bee is one of the most important pollinators with a close relationship to humans. The questionnaire from the non-governmental association “COLOSS”, answered by beekeepers around the world, is a valuable tool for monitoring and analyzing factors involved in overwintering losses, as [...] Read more.

The honey bee is one of the most important pollinators with a close relationship to humans. The questionnaire from the non-governmental association “COLOSS”, answered by beekeepers around the world, is a valuable tool for monitoring and analyzing factors involved in overwintering losses, as well as for understanding the evolution of the beekeeping sector over the years. Between 2018–2021, Greece’s participation in this survey involved collecting data from 752 beekeepers and 81,903 hives, from almost the whole country, with a stable balance between professional/non-professional participants and hives, providing a solid representation of the beekeeping practices and winter losses during this period. The results of this study identify a transition towards more natural beekeeping practices concomitant with a significant decrease in winter losses (average losses in 2018: 22.3% and 2019: 24%, dropped in 2020: 14.4% and 2021: 15.3%). Indeed, some factors, such as the increased use of natural landscapes for honey production (from 66.7% usage in 2018 to 76.3% in 2021) and the reduction in the exclusive use of synthetic acaricides (from 24.7% usage in 2018 to 6.7% in 2021) seem to have a significant impact on hive survival. Although these correlations remain to be confirmed experimentally, our study shows that Greek beekeepers follow recommendations and policies toward more sustainable practices. In the future, these trends could be further analyzed and integrated into training programs to strengthen the cooperation and information exchange between citizens and science. Full article

(This article belongs to the Special Issue Losses of Honey Bee Colonies across the World)

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14 pages, 2899 KiB

Open AccessArticle

Molecular-Based Taxonomic Inferences of Some Spider Mite Species of the Genus Oligonychus Berlese (Acari, Prostigmata, Tetranychidae)

by Hafiz Muhammad Saqib Mushtaq, Amgad A. Saleh, Muhammad Kamran and Fahad Jaber Alatawi

Insects 2023, 14(2), 192; https://doi.org/10.3390/insects14020192 - 15 Feb 2023

Cited by 3 | Viewed by 1419

Abstract

DNA barcoding technology using short DNA sequences has emerged as an efficient and reliable tool for identifying, confirming, and resolving closely related taxa. This study used ITS2-rDNA and mtCOI DNA sequences to confirm the identity of eight Oligonychus species, representing 68 spider mite [...] Read more.

DNA barcoding technology using short DNA sequences has emerged as an efficient and reliable tool for identifying, confirming, and resolving closely related taxa. This study used ITS2-rDNA and mtCOI DNA sequences to confirm the identity of eight Oligonychus species, representing 68 spider mite samples, collected mainly from Saudi Arabia (SA) and some from Mexico, Pakistan, USA, and Yemen. The intraspecific nucleotide divergences of the studied Oligonychus species ranged from 0% to 1.2% for ITS2 and 0% to 2.9% for COI. However, the interspecific nucleotide divergences were distinctly higher than the intraspecific ones and ranged from 3.7% to 51.1% for ITS2 and 3.2% to 18.1% for COI. Furthermore, molecular data correctly confirmed the species identity of 42 Oligonychus samples lacking males, including a previously claimed sample of O. pratensis from SA. High genetic variations were detected in two Oligonychus species: O. afrasiaticus (McGregor) (nine ITS2 and three COI haplotypes) and O. tylus Baker and Pritchard (four ITS2 and two COI haplotypes). In addition, ITS2- and COI-based phylogenetic trees confirmed the subdivision of the genus Oligonychus. In conclusion, integrative taxonomic approaches are vital to resolve the closely related Oligonychus species, identify the samples lacking male specimens, and assess phylogenetic relationships within and among species. Full article

(This article belongs to the Special Issue Mites: Systematics, Ecology, and Evolution)

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16 pages, 3655 KiB

Open AccessFeature PaperArticle

Patterns and Drivers of Aboveground Insect Diversity along Ecological Transect in Temperate Grazed Steppes of Eastern Eurasian

by Xiaoxiao Song, Lei Ji, Guangming Liu, Xiao Zhang, Xiangyang Hou, Shujing Gao and Ning Wang

Insects 2023, 14(2), 191; https://doi.org/10.3390/insects14020191 - 15 Feb 2023

Cited by 1 | Viewed by 2119

Abstract

Insects are important components of biodiversity and play significant roles in the steppe ecosystem. They are abundant, easy to sample, and sensitive to changing conditions, making them useful indicators of environmental changes. This study aims to describe patterns (α and β) of insect [...] Read more.

Insects are important components of biodiversity and play significant roles in the steppe ecosystem. They are abundant, easy to sample, and sensitive to changing conditions, making them useful indicators of environmental changes. This study aims to describe patterns (α and β) of insect diversity across two steppe types (a typical steppe and a desert steppe) along the Eastern Eurasian Steppe Transect (EEST), as well as evaluate the effects of environmental variables in determining these patterns and the influence of plant diversity alterations on these effects. To this end, we collected 5244 individual insects and found an n-shaped diversity distribution along the latitudinal gradient and a significant difference in insect communities across the two steppe types. Further, the Mantel test and path analysis indicate that climate and grazing activities combine to influence insect diversity, and these effects are mediated through plant diversity, strongly supporting the role of bottom-up effects in situations of climatic and grazing pattern changes. Moreover, the contribution of plant diversity varied with steppe types and insect functional groups, with greater effects seen in the typical steppe and herbivorous insects. This indicated the importance of protecting species diversity in steppes through managing plant diversity and assessments of local environmental factors such as grazing intensity and temperature. Full article

(This article belongs to the Topic Arthropod Biodiversity: Ecological and Functional Aspects)

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12 pages, 1723 KiB

Open AccessFeature PaperArticle

Characterization and Functional Analysis of OcomOBP7 in Ophraella communa Lesage

by Yang Yue, Chao Ma, Yan Zhang, Hong-Song Chen, Jian-Ying Guo, Ting-Hui Liu and Zhong-Shi Zhou

Insects 2023, 14(2), 190; https://doi.org/10.3390/insects14020190 - 14 Feb 2023

Cited by 2 | Viewed by 1345

Abstract

The olfactory system plays a key role in various insect behaviors, and odorant-binding proteins participate in the first step of the olfactory process. Ophraella communa Lesage is an oligophagous phytophagous insect that is a specific biological control agent for Ambrosia artemisiifolia L. The [...] Read more.

The olfactory system plays a key role in various insect behaviors, and odorant-binding proteins participate in the first step of the olfactory process. Ophraella communa Lesage is an oligophagous phytophagous insect that is a specific biological control agent for Ambrosia artemisiifolia L. The leaf beetle must identify and locate A. artemisiifolia through olfaction; however, its odorant-binding protein (OBP) function has not yet been reported. In this study, OcomOBP7 was cloned, and its tissue expression profile and binding ability were analyzed using RT-qPCR and fluorescence binding assays, respectively. Sequence analysis demonstrated that OcomOBP7 belongs to the classical OBP family. The RT-qPCR results showed that OcomOBP7 was specifically expressed in the antennae, indicating that OcomOBP7 may be involved in chemical communication. The fluorescence binding assay showed that OcomOBP7 has an extensive binding ability to alkenes. The electroantennography experiments showed that O. communa antennal response to α-pinene and ocimene decreased significantly after interference because the two odors specifically bound to OcomOBP7. In summary, α-pinene and ocimene are odorant ligands corresponding to OcomOBP7, indicating that OcomOBP7 is involved in the chemical recognition of A. artemisiifolia. Our study lays a theoretical foundation for research into O. communa attractants, which is helpful for the better biological control of A. artemisiifolia by O. communa. Full article

(This article belongs to the Section Insect Molecular Biology and Genomics)

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12 pages, 27642 KiB

Open AccessFeature PaperArticle

Elongases of Long-Chain Fatty Acids ELO2 and ELO9 Are Involved in Cuticle Formation and Function in Fecundity in the Yellow Fever Mosquito, Aedes aegypti

by Jing Chen, Yu-Chen Wu, Jiu-Kai Chen, Xiao-Jing Zhu, David Merkler, Cheng-Hong Liao and Qian Han

Insects 2023, 14(2), 189; https://doi.org/10.3390/insects14020189 - 14 Feb 2023

Cited by 1 | Viewed by 1560

Abstract

Long-chain fatty acid elongases (ELOs) play important roles in the metabolism of fatty acids in insects. In this study, the genes for two elongases from Aedes aegypti were identified, AeELO2 and AeELO9. Quantitative real time PCR showed that AeELO2 and AeELO9 are [...] Read more.

Long-chain fatty acid elongases (ELOs) play important roles in the metabolism of fatty acids in insects. In this study, the genes for two elongases from Aedes aegypti were identified, AeELO2 and AeELO9. Quantitative real time PCR showed that AeELO2 and AeELO9 are expressed at all developmental stages and some body parts, but with different expression patterns. RNAi-mediated knockdown of AeELO2 and AeELO9 was performed to investigate their roles in the development, growth, osmotic balance, and cold tolerance of Ae. aegypti. Knockdown of AeELO2 slowed larval growth and development by causing molting abnormalities. Additionally, 33% ± 3.3% of adults died during oviposition, accompanied by an abnormal extension of cuticles in AeELO2-dsRNA knockdown mosquitos. Knockdown of AeEL09 resulted in abnormal balance of cuticular osmotic pressure and a reduction in egg production. The maximal mRNAs of AeELO2 and AeELO9 were detected in eggs at 72 h after oviposition. Moreover, AeELO2 knockdown reduced the egg hatching rates and AeELO9 knockdown larvae did not develop well. In summary, AeELO2 is involved in larval molting and growth, and its knockdown affects the flexibility and elasticity of adult mosquito cuticles. AeELO9 regulates cold tolerance, osmotic balance, and egg development in Ae. aegypti. Full article

(This article belongs to the Special Issue Sterile Insect Technique and Mosquito Control)

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14 pages, 1076 KiB

Open AccessArticle

Effect of Fruit Volatiles from Native Host Plants on the Sexual Performance of Anastrepha fraterculus sp. 1 Males

by Guillermo Enrique Bachmann, Silvina Anahí Belliard, Francisco Devescovi, Ana Laura Nussenbaum, Patricia Carina Fernández, María Teresa Vera, María Josefina Ruiz and Diego Fernando Segura

Insects 2023, 14(2), 188; https://doi.org/10.3390/insects14020188 - 14 Feb 2023

Cited by 1 | Viewed by 1314

Abstract

Anastrepha fraterculus sp.1 males are sexually stimulated by the aroma of fruit of its native host Psidium guajava (guava). Other hosts, which are exotic to A. fraterculus, do not enhance male sexual behavior. Here we evaluate the effects of fruit volatile exposure [...] Read more.

Anastrepha fraterculus sp.1 males are sexually stimulated by the aroma of fruit of its native host Psidium guajava (guava). Other hosts, which are exotic to A. fraterculus, do not enhance male sexual behavior. Here we evaluate the effects of fruit volatile exposure on male A. fraterculus sp. 1 sexual performance using other native hosts, under the hypothesis that male improvement derives from a common evolutionary history between A. fraterculus sp. 1 and its native hosts. Four species were evaluated: Eugenia myrcianthes, Juglans australis, Psidium cattleianum, and Acca sellowiana. Guava was used as a positive control. Males were exposed to fruit from 12:00 pm to 4:00 pm, from day 8 to day 11 post-emergence. On day 12, we evaluated their calling behavior and mating success. Both guava and P. cattleianum enhanced calling behavior. Mating success was enhanced only by guava and a trend was found for P. cattleianum. Interestingly, the two hosts belong to the Psidium genus. A volatile analysis is planned to identify the compounds responsible for this phenomenon. The other native fruits did not improve the sexual behavior of males. Implications of our findings in the management of A. fraterculus sp. 1 are discussed. Full article

(This article belongs to the Special Issue Genetics and Ecological Evolution of Dipteran Pest Species)

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43 pages, 1164 KiB

Open AccessReview

What Are the Functional Roles of Piwi Proteins and piRNAs in Insects?

by Dulce Santos, Min Feng, Anna Kolliopoulou, Clauvis N. T. Taning, Jingchen Sun and Luc Swevers

Insects 2023, 14(2), 187; https://doi.org/10.3390/insects14020187 - 14 Feb 2023

Cited by 5 | Viewed by 2931

Abstract

Research on Piwi proteins and piRNAs in insects has focused on three experimental models: oogenesis and spermatogenesis in Drosophila melanogaster, the antiviral response in Aedes mosquitoes and the molecular analysis of primary and secondary piRNA biogenesis in Bombyx mori-derived BmN4 cells. [...] Read more.

Research on Piwi proteins and piRNAs in insects has focused on three experimental models: oogenesis and spermatogenesis in Drosophila melanogaster, the antiviral response in Aedes mosquitoes and the molecular analysis of primary and secondary piRNA biogenesis in Bombyx mori-derived BmN4 cells. Significant unique and complementary information has been acquired and has led to a greater appreciation of the complexity of piRNA biogenesis and Piwi protein function. Studies performed in other insect species are emerging and promise to add to the current state of the art on the roles of piRNAs and Piwi proteins. Although the primary role of the piRNA pathway is genome defense against transposons, particularly in the germline, recent findings also indicate an expansion of its functions. In this review, an extensive overview is presented of the knowledge of the piRNA pathway that so far has accumulated in insects. Following a presentation of the three major models, data from other insects were also discussed. Finally, the mechanisms for the expansion of the function of the piRNA pathway from transposon control to gene regulation were considered. Full article

(This article belongs to the Special Issue RNAi in Insects)

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9 pages, 1845 KiB

Open AccessCommunication

The Sweetgum Inscriber, Acanthotomicus suncei (Coleoptera: Curculionidae: Scolytinae) Reared on Artificial Diets and American Sweetgum Logs

by Yan Zhang, Xueting Sun, You Li and Lei Gao

Insects 2023, 14(2), 186; https://doi.org/10.3390/insects14020186 - 14 Feb 2023

Viewed by 1337

Abstract

The sweetgum inscriber, Acanthotomicus suncei (Coleoptera: Curculionidae: Scolytinae), is a recently discovered pest of American sweetgum planted in China, with a potential for causing a devastating invasion into North America. Research on the beetle has been hampered by a dwindling access to breeding [...] Read more.

The sweetgum inscriber, Acanthotomicus suncei (Coleoptera: Curculionidae: Scolytinae), is a recently discovered pest of American sweetgum planted in China, with a potential for causing a devastating invasion into North America. Research on the beetle has been hampered by a dwindling access to breeding material. We tested the effect of four artificial diets on A. suncei’s developmental time, length and weight of adults, egg hatching rate, pupation rate, and eclosion rate. Additionally, we evaluated the same parameters on A. suncei reared on American sweetgum logs. Only one diet supported the full development of A. suncei after 30 d. Beetles reared on this diet, which was made of small quantities of agar and additives (i.e., inositol, potassium sorbate, and methylparaben), supported the shortest developmental time of 45.55 ± 1.24 d. Beetles reared on American sweetgum logs exhibited a longer developmental time of 59.52 ± 4.52 d. Beetles reared on the artificial diet were markedly bigger and heavier than those reared on American sweetgum logs (p < 0.01). The egg hatching rate (58.90% ± 6.80%) and eclosion rate (86.50% ± 4.69%) of A. suncei on the artificial diet were significantly greater than those on sweetgum logs. However, the pupation rate (38.60% ± 8.36%) was much lower on the artificial diet than on the sweetgum logs. Here, we reported the best artificial diet for A. suncei and discuss the advantages and disadvantages over rearing the beetle on American sweetgum logs. Full article

(This article belongs to the Special Issue Advances in Insect Diet and Rearing Methodology (Volume II))

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8 pages, 742 KiB

Open AccessCommunication

Comparison of the Germination Conditions of Two Large-Spore Microsporidia Using Potassium and Sodium Ion Solutions

by Yuji Imura, Haruka Nakamura, Reina Arai and Yoshinori Hatakeyama

Insects 2023, 14(2), 185; https://doi.org/10.3390/insects14020185 - 13 Feb 2023

Cited by 3 | Viewed by 1334

Abstract

The germination of a microsporidian polar tube generally occurs under alkaline conditions. Typically, microsporidian spores can be stored in physiological salt solution for short periods. However, because of differences in the lodging area, the requirements may not always be uniform. In fact, Trachipleistophora [...] Read more.

The germination of a microsporidian polar tube generally occurs under alkaline conditions. Typically, microsporidian spores can be stored in physiological salt solution for short periods. However, because of differences in the lodging area, the requirements may not always be uniform. In fact, Trachipleistophora sp. OSL-2012-10 (nomen nudum Trachipleistophora haruka) germinated when preserved in physiological salt solution. In this study, the germination characteristics of the large-spore microsporidia Trachipleistophora sp. FOA-2014-10 and Vavraia sp. YGSL-2015-13 were compared with those of Trachipleistophora sp. OSL-2012-10; moreover, we investigated whether these characteristics are specific to these microsporidia. We found that both microsporidia germinated in physiological salt solution. These differences in germination rates were affected by the preservation solution and temperature. Full article

(This article belongs to the Special Issue Infectious Diseases in Beneficial Insects: Current Status of Pébrine and Nosema Diseases and Their Progression)

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13 pages, 1892 KiB

Open AccessFeature PaperArticle

Microbiome Composition and Microbial Community Structure in Mosquito Vectors Aedes aegypti and Aedes albopictus in Northeastern Thailand, a Dengue-Endemic Area

by Rutchanee Rodpai, Patcharaporn Boonroumkaew, Lakkhana Sadaow, Oranuch Sanpool, Penchom Janwan, Tongjit Thanchomnang, Pewpan M. Intapan and Wanchai Maleewong

Insects 2023, 14(2), 184; https://doi.org/10.3390/insects14020184 - 13 Feb 2023

Cited by 2 | Viewed by 2032

Abstract

Bacterial content in mosquito larvae and adults is altered by dynamic interactions during life and varies substantially in variety and composition depending on mosquito biology and ecology. This study aimed to identify the microbiota in Aedes aegypti and Aedes albopictus and in water [...] Read more.

Bacterial content in mosquito larvae and adults is altered by dynamic interactions during life and varies substantially in variety and composition depending on mosquito biology and ecology. This study aimed to identify the microbiota in Aedes aegypti and Aedes albopictus and in water from their breeding sites in northeastern Thailand, a dengue-endemic area. Bacterial diversity in field-collected aquatic larvae and subsequently emerged adults of both species from several locations were examined. The microbiota was characterized based on analysis of DNA sequences from the V3-V4 region of the 16S rRNA gene and exhibited changes during development, from the mosquito larval stage to the adult stage. Aedes aegypti contained a significantly higher number of bacterial genera than did Ae. albopictus, except for the genus Wolbachia, which was present at significantly higher frequencies in male Ae. albopictus (p < 0.05). Our findings also indicate likely transstadial transmission from larva to adult and give better understanding of the microbial diversity in these mosquitoes, informing future control programs against mosquito-borne diseases. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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18 pages, 1993 KiB

Open AccessEditor’s ChoiceArticle

Hemp Waste as a Substrate for Hermetia illucens (L.) (Diptera: Stratiomyidae) and Tenebrio molitor L. (Coleoptera: Tenebrionidae) Rearing

by Wael Yakti, Nadja Förster, Marcus Müller, Inga Mewis and Christian Ulrichs

Insects 2023, 14(2), 183; https://doi.org/10.3390/insects14020183 - 13 Feb 2023

Cited by 6 | Viewed by 2756

Abstract

The proper treatment of cannabis agricultural wastes can reduce the environmental impact of its cultivation and generate valuable products. This study aimed to test the potential of cannabis agricultural wastes as a substrate for the rearing of black soldier fly larvae (BSFL) and [...] Read more.

The proper treatment of cannabis agricultural wastes can reduce the environmental impact of its cultivation and generate valuable products. This study aimed to test the potential of cannabis agricultural wastes as a substrate for the rearing of black soldier fly larvae (BSFL) and yellow mealworms (MW). In the case of BSFL, replacing the fibre component (straw) in the substrate with the hemp waste can increase the nutritional value of the substrate and led to bigger larvae. The bigger larvae had lower P and Mg, and higher Fe and Ca. Crude protein also varied based on the size of larvae and/or the content of protein in the initial substrate, which was boosted by replacing straw with hemp material. No other cannabinoids than cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), and cannabidiol (CBD) were found in significant amounts in the larvae. In the case of MW, the larvae grew less on the hemp material in comparison to wheat bran. Replacing wheat bran with the hemp material led to smaller larvae with higher Ca, Fe, K, and crude protein content, but lower Mg and P values. No cannabinoids were detected in the MW fed with the hemp material. Full article

(This article belongs to the Special Issue Insects at the Center of the Green Transition)

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