Insects

14 pages, 1795 KiB

Open AccessArticle

Assessing the Pathogenicity of Two Bacteria Isolated from the Entomopathogenic Nematode Heterorhabditis indica against Galleria mellonella and Some Pest Insects

by Rosalba Salgado-Morales, Fernando Martínez-Ocampo, Verónica Obregón-Barboza, Kathia Vilchis-Martínez, Alfredo Jiménez-Pérez and Edgar Dantán-González

Insects 2019, 10(3), 83; https://doi.org/10.3390/insects10030083 - 26 Mar 2019

Cited by 6 | Viewed by 4005

Abstract

The entomopathogenic nematodes Heterorhabditis are parasites of insects and are associated with mutualist symbiosis enterobacteria of the genus Photorhabdus; these bacteria are lethal to their host insects. Heterorhabditis indica MOR03 was isolated from sugarcane soil in Morelos state, Mexico. The molecular identification [...] Read more.

The entomopathogenic nematodes Heterorhabditis are parasites of insects and are associated with mutualist symbiosis enterobacteria of the genus Photorhabdus; these bacteria are lethal to their host insects. Heterorhabditis indica MOR03 was isolated from sugarcane soil in Morelos state, Mexico. The molecular identification of the nematode was confirmed using sequences of the ITS1-5.8S-ITS2 region and the D2/D3 expansion segment of the 28S rRNA gene. In addition, two bacteria HIM3 and NA04 strains were isolated from the entomopathogenic nematode. The genomes of both bacteria were sequenced and assembled de novo. Phylogenetic analysis was confirmed by concatenated gene sequence datasets as Photorhabdus luminescens HIM3 (16S rRNA, 23S rRNA, dnaN, gyrA, and gyrB genes) and Pseudomonas aeruginosa NA04 (16S rRNA, 23S rRNA and gyrB genes). H. indica MOR03 infects Galleria mellonella, Tenebrio molitor, Heliothis subflexa, and Diatraea magnifactella larvae with LC50 values of 1.4, 23.5, 13.7, and 21.7 IJs/cm², respectively, at 48 h. These bacteria are pathogenic to various insects and have high injectable insecticide activity at 24 h. Full article

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7 pages, 2998 KiB

Open AccessCommunication

Unusual Behavior of Xylosandrus compactus (Coleoptera: Scolytinae) on Carob Trees in a Mediterranean Environment

by Antonio Gugliuzzo, Giulio Criscione and Giovanna Tropea Garzia

Insects 2019, 10(3), 82; https://doi.org/10.3390/insects10030082 - 23 Mar 2019

Cited by 20 | Viewed by 6469

Abstract

Xylosandrus compactus (Eichhoff), commonly known as the black twig borer, was reported in Sicily (Italy) at the end of 2016, infesting Carob tree (Ceratonia siliqua L.) twigs, large branches, and trunks. Previous research indicated that X. compactus attacks only small twigs and [...] Read more.

Xylosandrus compactus (Eichhoff), commonly known as the black twig borer, was reported in Sicily (Italy) at the end of 2016, infesting Carob tree (Ceratonia siliqua L.) twigs, large branches, and trunks. Previous research indicated that X. compactus attacks only small twigs and branches, not large branches and tree trunks. This unusual behavior was monitored through the two following years in five sites in Ragusa province (Sicily, Italy). For each of the monitored sites, the diameter of the infested trunks and branches was recorded. Samples of branches and trunks presenting galleries were removed from the trees and analyzed in the laboratory. Xylosandrus compactus occurred on branches of all monitored trees, while the percentage of infested trunks of carob trees ranged from 60% to 80%. Inside the infested galleries, all biological stages of X. compactus were found. Infestations were also recorded on trunks and branches with diameters greater than 80 cm and 30 cm, respectively. The mean number of X. compactus specimens inside the galleries was recorded and gallery shape was described. Unordinary behaviors, like the one described here for the first time, can affect the current efficiency of management recommendations. Full article

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9 pages, 1064 KiB

Open AccessArticle

Losing the Arms Race: Greater Wax Moths Sense but Ignore Bee Alarm Pheromones

by Yuan Li, Xingchuan Jiang, Zhengwei Wang, Junjun Zhang, Katrina Klett, Shahid Mehmood, Yufeng Qu and Ken Tan

Insects 2019, 10(3), 81; https://doi.org/10.3390/insects10030081 - 23 Mar 2019

Cited by 7 | Viewed by 4588

Abstract

The greater wax moth, Galleria mellonella L., is one of main pests of honeybees. The larvae burrow into the wax, damaging the bee comb and degenerating bee products, but also causes severe effects like driving the whole colony to abscond. In the present [...] Read more.

The greater wax moth, Galleria mellonella L., is one of main pests of honeybees. The larvae burrow into the wax, damaging the bee comb and degenerating bee products, but also causes severe effects like driving the whole colony to abscond. In the present study, we used electroantennograms, a Y maze, and an oviposition site choice bioassay to test whether the greater wax moth can eavesdrop on bee alarm pheromones (isopentyl acetate, benzyl acetate, octyl acetate, and 2-heptanone), to target the bee colony, or if the bee alarm pheromones would affect their preference of an oviposition site. The results revealed that the greater wax moth showed a strong electroantennogram response to these four compounds of bee alarm pheromones even in a low concentration (100 ng/μL), while they showed the highest response to octyl acetate compared to the other three main bee alarm components (isopentyl acetate, benzyl acetate, and 2-heptanone). However, the greater wax moth behavioral results showed no significant preference or avoidance to these four bee alarm pheromones. These results indicate that bees are currently losing the arms race since the greater wax moth can sense bee alarm pheromones, however, these alarm pheromones are ignored by the greater wax moth. Full article

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18 pages, 5987 KiB

Open AccessArticle

Brown Rice Vinegar as an Olfactory Field Attractant for Drosophila suzukii (Matsumura) and Zaprionus indianus Gupta (Diptera: Drosophilidae) in Cherimoya in Maui, Hawaii, with Implications for Attractant Specificity between Species and Estimation of Relative Abundance

by Brittany N. Willbrand and Douglas G. Pfeiffer

Insects 2019, 10(3), 80; https://doi.org/10.3390/insects10030080 - 20 Mar 2019

Cited by 3 | Viewed by 3639

Abstract

Drosophila suzukii (Matsumura) is an agricultural pest that has been observed co-infesting soft-skinned fruits with Zaprionus indianus Gupta. The characterization of olfactory preferences by species is a necessary step towards the development of species-specific attractants. Five olfactory attractants were used to survey the [...] Read more.

Drosophila suzukii (Matsumura) is an agricultural pest that has been observed co-infesting soft-skinned fruits with Zaprionus indianus Gupta. The characterization of olfactory preferences by species is a necessary step towards the development of species-specific attractants. Five olfactory attractants were used to survey the populations of two invasive drosophilids in cherimoya in Maui, Hawaii. The attractants used were apple cider vinegar (ACV), brown rice vinegar (BRV), red wine (RW), apple cider vinegar and red wine (ACV+RW; 60/40), and brown rice vinegar and red wine (BRV+RW; 60/40). For D. suzukii, BRV+RW resulted in more captures than BRV, ACV, and RW, while ACV+RW resulted in more captures than ACV. No differences were observed between BRV+RW and ACV+RW. BRV had greater specificity in attracting D. suzukii compared to ACV, ACV+RW, and RW. For Z. indianus, no significant differences were observed in either the mean captures or specificity for any attractant used. Collectively, these findings demonstrate that (1) BRV and BRV+RW are effective field attractants and (2) D. suzukii has unique olfactory preferences compared to non-target drosophilids, while (3) Z. indianus’ preferences do not appear to vary from non-target drosophilids, and (4) the accuracy of relative abundance is impacted by the specificity of the attractants. Full article

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13 pages, 4384 KiB

Open AccessArticle

Characterization and Function of Two Short Peptidoglycan Recognition Proteins Involved in the Immunity of Bactrocera dorsalis (Hendel)

by Dong Wei, Yu-Wei Liu, Ying-Xin Zhang and Jin-Jun Wang

Insects 2019, 10(3), 79; https://doi.org/10.3390/insects10030079 - 19 Mar 2019

Cited by 6 | Viewed by 2645

Abstract

Peptidoglycans (PGNs) are major bacterial components recognized by the immune systems of insects and mammals. PGN recognition proteins (PGRPs) are widely distributed and highly conserved in vertebrates and invertebrates. PGRPs are a family of pattern recognition receptors that recognize peptidoglycan and regulate immune [...] Read more.

Peptidoglycans (PGNs) are major bacterial components recognized by the immune systems of insects and mammals. PGN recognition proteins (PGRPs) are widely distributed and highly conserved in vertebrates and invertebrates. PGRPs are a family of pattern recognition receptors that recognize peptidoglycan and regulate immune responses. In this study, we cloned two PGRP genes (BdPGRP-SA and BdPGRP-SD) from Bactrocera dorsalis (Hendel), which encode 192 and 196 amino acid residues, respectively. Both genes were highly expressed in adults, especially in the fat body and midgut. These two genes were up-regulated when challenged by the immune triggers, PGN-EB (Escherichia coli O111:B4) and PGN-SA (Staphylococcus aureus). The suppression of transcriptional expression of either gene by RNA interference (RNAi) resulted in increased sensitivities to Gram-negative E. coli and Gram-positive S. aureus PGNs. Suppression of BdPGRP-SA and -SD expression by RNAi resulted in weak expressions of four antimicrobial peptides (AMPs) upon injected with E. coli or S. aureus. BdPGRP-SA and -SD are involved in recognizing both Gram-negative and Gram-positive bacteria independently to activate the downstream AMP’s response to bacterial infection. Full article

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10 pages, 728 KiB

Open AccessArticle

Chemical Compounds from Female and Male Rectal Pheromone Glands of the Guava Fruit Fly, Bactrocera correcta

by Xiuge Zhang, Chengmei Wei, Jin Miao, Xiaojiao Zhang, Bo Wei, Wenxia Dong and Chun Xiao

Insects 2019, 10(3), 78; https://doi.org/10.3390/insects10030078 - 18 Mar 2019

Cited by 13 | Viewed by 3763

Abstract

The guava fruit fly, Bactrocera correcta, is one of the major pests affecting mango (Mangifera indica) and guava (Psidium guajava) production in China. The compound β-caryophyllene was identified from the rectal gland extracts of wild B. correcta males [...] Read more.

The guava fruit fly, Bactrocera correcta, is one of the major pests affecting mango (Mangifera indica) and guava (Psidium guajava) production in China. The compound β-caryophyllene was identified from the rectal gland extracts of wild B. correcta males and was demonstrated to be a more specific and potent male lure than methyl eugenol (ME) for B. correcta. In order to find potential additional pheromone attractants for the monitoring and mass-trapping of this fruit fly, a series of chemical and behavioral assays were conducted in this study. Ten compounds were identified from the rectal glands of virgin B. correcta females. These compounds consisted of five major compounds (i.e., ethyl dodecanoate, ethyl tetradecanoate, ethyl (E)-9-hexadecenoate, ethyl hexadecanoate, and ethyl (Z)-9-octadecenoate) in high quantities, and other compounds (i.e., octanal, N-(3-methylbutyl) acetamide, (Z)-9-tricosene, ethyl octadecanoate, and ethyl eicosanoate) in trace amounts, while virtually no compounds were found in male rectal glands. The bioassays indicate that female rectal gland extracts are attractive to virgin females and males. Furthermore, a cyclical production of the five major compounds was found, recurring at roughly 10-d intervals with peaks in 10–13-, 25-, and 35-d-old females. Collectively, these results will contribute to the understanding of pheromone communication in B. correcta and may provide important information for improving existing monitoring and control methods for this pest. Full article

(This article belongs to the Special Issue Semiochemicals and Insect Behavior)

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20 pages, 2878 KiB

Open AccessReview

Sanitation Improves Stored Product Insect Pest Management

by William R. Morrison III, Alexander Bruce, Rachel V. Wilkins, Chloe E. Albin and Frank H. Arthur

Insects 2019, 10(3), 77; https://doi.org/10.3390/insects10030077 - 17 Mar 2019

Cited by 43 | Viewed by 7993

Abstract

There is a large suite of insects that attack anthropogenic agricultural goods after harvest. Proper sanitation programs for food facilities are now recognized as the foundation of good integrated pest management (IPM) programs for stored products throughout the post-harvest supply chain. While good [...] Read more.

There is a large suite of insects that attack anthropogenic agricultural goods after harvest. Proper sanitation programs for food facilities are now recognized as the foundation of good integrated pest management (IPM) programs for stored products throughout the post-harvest supply chain. While good sanitation programs are generally thought to reduce the abundance and diversity of insects, there has been less appreciation of the manifold ways that sanitation interacts with a range of other IPM tactics to modulate their efficacy. Here, we review the literature on how the effectiveness of chemical, physical/cultural, biological, and behaviorally-based control tactics varies with changes in sanitation. In addition, we discuss how sanitation may affect ongoing pheromone- and kairomone-based monitoring programs. Where possible, we quantitatively compile and analyze the impact of sanitation on the fold-change in the efficacy of IPM tactics. We found that decreased sanitation negatively affected the efficacy of most tactics examined, with a mean 1.3–17-fold decrease in efficacy under poorer sanitation compared to better sanitation. Sanitation had neutral or mixed impacts on a few tactics as well. Overall, the literature suggests that sanitation should be of the utmost importance for food facility managers concerned about the efficacy of a wide range of management tactics. Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

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20 pages, 5508 KiB

Open AccessArticle

Molecular Cloning and Expression Analysis of Three Suppressors of Cytokine Signaling Genes (SOCS5, SOCS6, SOCS7) in the Mealworm Beetle Tenebrio molitor

by Bharat Bhusan Patnaik, Bo Bae Kim, Yong Hun Jo and In Seok Bang

Insects 2019, 10(3), 76; https://doi.org/10.3390/insects10030076 - 16 Mar 2019

Cited by 12 | Viewed by 3439

Abstract

Suppressors of cytokine signaling (SOCS) influence cytokine and growth factor signaling by negatively regulating the Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway to maintain homeostasis during immune responses. However, functional characterization of SOCS family members in invertebrates is limited. Here, [...] Read more.

Suppressors of cytokine signaling (SOCS) influence cytokine and growth factor signaling by negatively regulating the Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway to maintain homeostasis during immune responses. However, functional characterization of SOCS family members in invertebrates is limited. Here, we identified and evaluated three SOCS genes (type I sub-family) in the mealworm beetle Tenebrio molitor. The full-length open reading frames (ORFs) of TmSOCS5, TmSOCS6, and TmSOCS7 comprised of 1389, 897, and 1458 nucleotides, encoding polypeptides of 462, 297, and 485 amino acids, respectively. The SH2 and SOCS box domains of the TmSOCS C-terminal region were highly conserved. Phylogenetic analysis revealed that these SOCS genes were clustered within the type I subfamily that exhibits the highest amino acid identity with Tribolium castaneum SOCS genes. Contrary to TmSOCS7 expression, the expression levels of TmSOCS5 and TmSOCS6 were lower in the larval, pupal, and adult stages. In larvae and adults, the expression levels of TmSOCS5 and TmSOCS6 were highest in the hemocytes and ovaries, respectively. SOCS transcripts were also highly upregulated in the hemocytes of T. molitor larvae within 3–6 h post-infection with the fungus Candida albicans. Collectively, these results provide valuable information regarding the involvement of TmSOCS type-I subfamily in the host immune response of insects. Full article

(This article belongs to the Special Issue Insect Immunity and Pathology)

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11 pages, 902 KiB

Open AccessArticle

How Cabbage Aphids Brevicoryne brassicae (L.) Make a Choice to Feed on Brassica napus Cultivars

by Zhong-Ping Hao, Hai-Xia Zhan, Yu-Long Wang and Shu-Min Hou

Insects 2019, 10(3), 75; https://doi.org/10.3390/insects10030075 - 15 Mar 2019

Cited by 12 | Viewed by 2897

Abstract

Plant resistance to aphids might be present in different plant tissues, such as the epidermis, mesophyll and phloem, but not all of them play a key role in determining the feeding preference of aphids. In this study, electrically recorded feeding behaviors of cabbage [...] Read more.

Plant resistance to aphids might be present in different plant tissues, such as the epidermis, mesophyll and phloem, but not all of them play a key role in determining the feeding preference of aphids. In this study, electrically recorded feeding behaviors of cabbage aphids were combined with choice tests and microscopic observations to understand the feeding preference of cabbage aphids on oilseed rape cultivars. The choice tests showed that more cabbage aphids survived on ‘Qianyou18’, and less on ‘Zhongshuang11’, compared with the other cultivars. The results of the choice tests were paradoxical with the results analyzed from the general and mesophyll-associated variables. The thick upper epidermis with bushy long trichomes on the leaves of ‘Zhongshuang11’ delayed the first probe of the cabbage aphids. The duration of phloem-feeding was similar among the four cultivars although there were differences in the hindrance of the mesophyll. However, salivation was increased when the aphids fed on ‘Zhongshuang11’, further indicating that the leaf’s physical properties could be important for aphid feeding preference on the four cultivars. Full article

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18 pages, 679 KiB

Open AccessReview

Physiological and Environmental Factors Affecting the Composition of the Ejaculate in Mosquitoes and Other Insects

by Megan E. Meuti and Sarah M. Short

Insects 2019, 10(3), 74; https://doi.org/10.3390/insects10030074 - 15 Mar 2019

Cited by 18 | Viewed by 6350

Abstract

In addition to transferring sperm, male mosquitoes deliver several proteins, hormones and other factors to females in their seminal fluid that inhibit remating, alter host-seeking behaviors and stimulate oviposition. Recently, bioinformatics, transcriptomics and proteomics have been used to characterize the genes transcribed in [...] Read more.

In addition to transferring sperm, male mosquitoes deliver several proteins, hormones and other factors to females in their seminal fluid that inhibit remating, alter host-seeking behaviors and stimulate oviposition. Recently, bioinformatics, transcriptomics and proteomics have been used to characterize the genes transcribed in male reproductive tissues and the individual proteins that are delivered to females. Thanks to these foundational studies, we now understand the complexity of the ejaculate in several mosquito species. Building on this work, researchers have begun to identify the functions of various proteins and hormones in the male ejaculate, and how they mediate their effects on female mosquitoes. Here, we present an overview of these studies, followed by a discussion of an under-studied aspect of male reproductive physiology: the effects of biotic and abiotic factors on the composition of the ejaculate. We argue that future research in this area would improve our understanding of male reproductive biology from a physiological and ecological perspective, and that researchers may be able to leverage this information to study key components of the ejaculate. Furthermore, this work has the potential to improve mosquito control by allowing us to account for relevant factors when implementing vector control strategies involving male reproductive biology. Full article

(This article belongs to the Special Issue Integrative Mosquito Biology: From Molecules to Ecosystems)

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14 pages, 5842 KiB

Open AccessArticle

Morphology and Morphometry of the Midgut in the Stingless Bee Friesella schrottkyi (Hymenoptera: Apidae)

by André H. Oliveira, Wagner G. Gonçalves, Kenner M. Fernandes, Marcelo S. Barcellos, Wagner M. S. Sampaio, Marcos P. Lopes, Gustavo F. Martins and José E. Serrão

Insects 2019, 10(3), 73; https://doi.org/10.3390/insects10030073 - 14 Mar 2019

Cited by 5 | Viewed by 3787

Abstract

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and [...] Read more.

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and endocrine cells. The digestive cells are similar along the entire midgut length with a spherical nucleus, apex with long striated border, cytoplasmic granules in the apical region and well-developed basal labyrinth associated with mitochondria, suggesting they are multifunctional, synthesizing digestive enzymes and peritrophic matrix compounds and absorbing nutrients. Regenerative cells are located around the basal region organized in nests with some cells with a spherical nucleus. Phe-Met-Arg-Phe-NH₂-amide (FMRFamide) positive endocrine cells are restricted to the posterior midgut region, suggesting a paracrine function in the midgut. This is the first morphological description of the F. schrottkyi midgut contributing to the comprehension of the digestive process of this bee. Full article

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25 pages, 1869 KiB

Open AccessArticle

Morphological and Molecular Analysis of Australian Earwigs (Dermaptera) Points to Unique Species and Regional Endemism in the Anisolabididae Family

by Oliver P. Stuart, Matthew Binns, Paul A. Umina, Joanne Holloway, Dustin Severtson, Michael Nash, Thomas Heddle, Maarten van Helden and Ary A. Hoffmann

Insects 2019, 10(3), 72; https://doi.org/10.3390/insects10030072 - 14 Mar 2019

Cited by 9 | Viewed by 4968

Abstract

Dermaptera (earwigs) from the Anisolabididae family may be important for pest control but their taxonomy and status in Australia is poorly studied. Here we used taxonomic information to assess the diversity of southern Australian Anisolabididae and then applied cox1 barcodes as well as [...] Read more.

Dermaptera (earwigs) from the Anisolabididae family may be important for pest control but their taxonomy and status in Australia is poorly studied. Here we used taxonomic information to assess the diversity of southern Australian Anisolabididae and then applied cox1 barcodes as well as additional gene fragments (mitochondrial and nuclear) to corroborate classification and assess the monophyly of the putative genera. Anisolabididae morphospecies fell into two genera, Anisolabis Fieber and Gonolabis Burr, based on paramere morphology. Combinations of paramere and forceps morphology distinguished seven morphospecies, which were further supported by morphometric analyses. The morphospecies were corroborated by barcode data; all showed within-species genetic distance < 4% and between-species genetic distance > 10%. Molecular phylogenies did not support monophyly of putative genera nor clades based on paramere shape, instead pointing to regional clades distinguishable by forceps morphology. This apparent endemism needs to be further tested by sampling of earwig diversity outside of agricultural production regions but points to a unique regional insect fauna potentially important in pest control. Full article

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11 pages, 1869 KiB

Open AccessArticle

Heterologous Expression of Aedes aegypti Cation Chloride Cotransporter 2 (aeCCC2) in Xenopus laevis Oocytes Induces an Enigmatic Na⁺/Li⁺ Conductance

by Megha Kalsi, Christopher Gillen and Peter M. Piermarini

Insects 2019, 10(3), 71; https://doi.org/10.3390/insects10030071 - 14 Mar 2019

Cited by 8 | Viewed by 3022

Abstract

The yellow fever mosquito Aedes aegypti possesses three genes encoding putative Na⁺-coupled cation chloride cotransporters (CCCs): aeNKCC1, aeCCC2, and aeCCC3. To date, none of the aeCCCs have been functionally characterized. Here we expressed aeCCC2 heterologously in Xenopus oocytes and measured the [...] Read more.

The yellow fever mosquito Aedes aegypti possesses three genes encoding putative Na⁺-coupled cation chloride cotransporters (CCCs): aeNKCC1, aeCCC2, and aeCCC3. To date, none of the aeCCCs have been functionally characterized. Here we expressed aeCCC2 heterologously in Xenopus oocytes and measured the uptake of Li⁺ (a tracer for Na⁺) and Rb⁺ (a tracer for K⁺). Compared to control (H₂O-injected) oocytes, the aeCCC2-expressing oocytes exhibited significantly greater uptake of Li⁺, but not Rb⁺. However, the uptake of Li⁺ was neither Cl⁻-dependent nor inhibited by thiazide, loop diuretics, or amiloride, suggesting unconventional CCC activity. To determine if the Li⁺-uptake was mediated by a conductive pathway, we performed two-electrode voltage clamping (TEVC) on the oocytes. The aeCCC2 oocytes were characterized by an enhanced conductance for Li⁺ and Na⁺, but not K⁺, compared to control oocytes. It remains to be determined whether aeCCC2 directly mediates the Na⁺/Li⁺ conductance or whether heterologous expression of aeCCC2 stimulates an endogenous cation channel in the oocyte plasma membrane. Full article

(This article belongs to the Special Issue Integrative Mosquito Biology: From Molecules to Ecosystems)

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23 pages, 3403 KiB

Open AccessReview

Ecological and Societal Services of Aquatic Diptera

by Peter H. Adler and Gregory W. Courtney

Insects 2019, 10(3), 70; https://doi.org/10.3390/insects10030070 - 14 Mar 2019

Cited by 41 | Viewed by 11646

Abstract

More than any other group of macro-organisms, true flies (Diptera) dominate the freshwater environment. Nearly one-third of all flies—roughly 46,000 species—have some developmental connection with an aquatic environment. Their abundance, ubiquity, and diversity of adaptations to the aquatic environment position them as major [...] Read more.

More than any other group of macro-organisms, true flies (Diptera) dominate the freshwater environment. Nearly one-third of all flies—roughly 46,000 species—have some developmental connection with an aquatic environment. Their abundance, ubiquity, and diversity of adaptations to the aquatic environment position them as major drivers of ecosystem processes and as sources of products and bioinspiration for the benefit of human society. Larval flies are well represented as ecosystem engineers and keystone species that alter the abiotic and biotic environments through activities such as burrowing, grazing, suspension feeding, and predation. The enormous populations sometimes achieved by aquatic flies can provide the sole or major dietary component for other organisms. Harnessing the services of aquatic Diptera for human benefit depends on the ingenuity of the scientific community. Aquatic flies have played a role as indicators of water quality from the earliest years of bioassessment. They serve as indicators of historical and future ecological and climate change. As predators and herbivores, they can serve as biological control agents. The association of flies with animal carcasses in aquatic environments provides an additional set of tools for forensic science. The extremophilic attributes of numerous species of Diptera offer solutions for human adaptation to harsh terrestrial and extraterrestrial environments. The potential pharmaceutical and industrial applications of the symbiotic microbial community in extremophilic Diptera are better explored than are those of dipteran chemistry. Many flies provide valuable ecological and human services as aquatic immatures, but are also pests and vectors of disease agents as terrestrial adults. The scientific community, thus, is challenged with balancing the benefits and costs of aquatic Diptera, while maintaining sustainable populations as more species face extinction. Full article

(This article belongs to the Special Issue Diversity and Ecosystem Services of Aquatic Insects)

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13 pages, 1709 KiB

Open AccessArticle

Use of Termites by Farmers as Poultry Feed in Ghana

by Hettie Arwoh Boafo, Siegfried Affedzie-Obresi, Dossou Séblodo Judes Charlemagne Gbemavo, Victor Attuquaye Clottey, Emmanuel Nkegbe, Gabriel Adu-Aboagye and Marc Kenis

Insects 2019, 10(3), 69; https://doi.org/10.3390/insects10030069 - 13 Mar 2019

Cited by 13 | Viewed by 4768

Abstract

The aim of the study was to gather information on the use of termites by farmers as feed for indigenous poultry in Ghana and factors affecting its use. We conducted surveys in four regions in Ghana to collect information, by the administration of [...] Read more.

The aim of the study was to gather information on the use of termites by farmers as feed for indigenous poultry in Ghana and factors affecting its use. We conducted surveys in four regions in Ghana to collect information, by the administration of questionnaires, on the use of termites as poultry feed, termite species collected, species not used and collection methods. Samples of termite species mentioned were collected and identified to the genus level. Twenty-three percent and 19% of farmers mentioned that termites are always or often used to feed poultry whereas 11% never use termites. A binomial regression analysis showed that their utilization was affected by region, sex, education, farm size and income. Termites collected belonged to eight genera, the main ones being Macrotermes, Trinervitermes and Odontotermes. Five collection methods are used to obtain termites and involve either breaking mounds or using containers as traps. Collection methods vary with species and region and the abundance of termite genera varies with season. Farmers identified some species as poisonous to poultry. Termites are important in indigenous poultry production because they are a readily available protein source for local farmers. However, better collection methods need to be developed to aid their optimal use. Full article

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14 pages, 1573 KiB

Open AccessArticle

Ability of Muscidifurax raptorellus and Other Parasitoids and Predators to Control Drosophila suzukii Populations in Raspberries in the Laboratory

by Phanie Bonneau, Justin Renkema, Valérie Fournier and Annabelle Firlej

Insects 2019, 10(3), 68; https://doi.org/10.3390/insects10030068 - 07 Mar 2019

Cited by 16 | Viewed by 4561

Abstract

Drosophila suzukii is an invasive pest and economic threat to berry crops in Europe and the Americas. Current methods of control of this pest rely primarily on frequent applications of insecticides; therefore, there is a need for alternative control methods to reduce insecticide [...] Read more.

Drosophila suzukii is an invasive pest and economic threat to berry crops in Europe and the Americas. Current methods of control of this pest rely primarily on frequent applications of insecticides; therefore, there is a need for alternative control methods to reduce insecticide reliance. In this study, we evaluated the biological control potential of three parasitoid wasps: Diglyphus isaea, Muscidifurax raptorellus and Pachycrepoideus vindemmiae, and four predators: Chrysoperla carnea, Dicyphus hesperus, Orius insidiosus and Podisus maculiventris. Experiments were conducted for 15 days under controlled conditions in experimental arenas with D. suzukii females and raspberries, allowing for all life stages of D. suzukii to be available to natural enemies. Results showed the first evidence of M. raptorellus’s ability to parasitize D. suzukii, resulting in a 40% reduction. Orius insidiosus, P. vindemmiae and C. carnea were also efficient, reducing D. suzukii numbers by 49%, 43% and 32%, respectively. Predator preferences for each D. suzukii life stage were assessed. The clutch size, sex ratio and adult size variability of D. suzukii pupal parasitoids were also evaluated. This study expands the list of species that can effectively parasitize D. suzukii and provides new insights into the biological responses of M. raptorellus to D. suzukii pupae. Full article

(This article belongs to the Special Issue Invasive Insect Species Modelling and Control)

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9 pages, 2034 KiB

Open AccessBrief Report

What Is the Carcass-Usage Mode of the Collembola? A Case Study of Entomobrya proxima in the Laboratory

by Lichao Feng, Liang Chang, Shaoqing Zhang, Xinyu Zhu, Sina Adl and Donghui Wu

Insects 2019, 10(3), 67; https://doi.org/10.3390/insects10030067 - 07 Mar 2019

Cited by 5 | Viewed by 2892

Abstract

Collembola display a variety of feeding habits, and prey on many types of food at different trophic levels in the soil. In most cases, their feeding selections are widely varied. In the interest of the food preferences of E. proxima, we attempted [...] Read more.

Collembola display a variety of feeding habits, and prey on many types of food at different trophic levels in the soil. In most cases, their feeding selections are widely varied. In the interest of the food preferences of E. proxima, we attempted to confirm how the Collembola utilize food when feeding on carrion (unusual sources). Four different soil animals (with different stable isotope values and increasing trophic levels) were used to examine whether collembolans can use dead insects as a food resource in specific manners, depending on food preference. Our results demonstrated that the food preference of a collembolan changed significantly after feeding on insects with different feeding habits for 60 days. We found that stable isotope values (δ¹³C) of Entomobrya proxima approached those of the food sources. A large proportion of the diet (more than 50%) should directly consist of insect body parts, with the remainder consisting of indirectly used, mixed microorganisms naturally growing on animal food, such as fungi (Rhizopus sp., Alternaria sp., Penicillium sp., and Aspergillus sp.) and bacteria (Bacillus sp1. and Bacillus sp2.). Based on this research, the food preference of collembolans is more focused on carcasses (dead insect bodies) than microorganisms during the animal-food decomposition process. Full article

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11 pages, 559 KiB

Open AccessCommunication

Insecticide Exposure Triggers a Modulated Expression of ABC Transporter Genes in Larvae of Anopheles gambiae s.s.

by Valentina Mastrantonio, Marco Ferrari, Agata Negri, Tommaso Sturmo, Guido Favia, Daniele Porretta, Sara Epis and Sandra Urbanelli

Insects 2019, 10(3), 66; https://doi.org/10.3390/insects10030066 - 05 Mar 2019

Cited by 20 | Viewed by 3380

Abstract

Insecticides remain a main tool for the control of arthropod vectors. The urgency to prevent the insurgence of insecticide resistance and the perspective to find new target sites, for the development of novel molecules, are fuelling the study of the molecular mechanisms involved [...] Read more.

Insecticides remain a main tool for the control of arthropod vectors. The urgency to prevent the insurgence of insecticide resistance and the perspective to find new target sites, for the development of novel molecules, are fuelling the study of the molecular mechanisms involved in insect defence against xenobiotic compounds. In this study, we have investigated if ATP-binding cassette (ABC) transporters, a major component of the defensome machinery, are involved in defence against the insecticide permethrin, in susceptible larvae of the malaria vector Anopheles gambiae sensu stricto. Bioassays were performed with permethrin alone, or in combination with an ABC transporter inhibitor. Then we have investigated the expression profiles of five ABC transporter genes at different time points following permethrin exposure, to assess their expression patterns across time. The inhibition of ABC transporters increased the larval mortality by about 15-fold. Likewise, three genes were up-regulated after exposure to permethrin, showing different patterns of expression across the 48 h. Our results provide the first evidences of ABC transporters involvement in defence against a toxic in larvae of An. gambiae s.s. and show that the gene expression response is modulated across time, being continuous, but stronger at the earliest and latest times after exposure. Full article

(This article belongs to the Special Issue Integrative Mosquito Biology: From Molecules to Ecosystems)

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22 pages, 4385 KiB

Open AccessArticle

Multi-Scenario Species Distribution Modeling

by Senait D. Senay and Susan P. Worner

Insects 2019, 10(3), 65; https://doi.org/10.3390/insects10030065 - 01 Mar 2019

Cited by 12 | Viewed by 5950

Abstract

Correlative species distribution models (SDMs) are increasingly being used to predict suitable insect habitats. There is also much criticism of prediction discrepancies among different SDMs for the same species and the lack of effective communication about SDM prediction uncertainty. In this paper, we [...] Read more.

Correlative species distribution models (SDMs) are increasingly being used to predict suitable insect habitats. There is also much criticism of prediction discrepancies among different SDMs for the same species and the lack of effective communication about SDM prediction uncertainty. In this paper, we undertook a factorial study to investigate the effects of various modeling components (species-training-datasets, predictor variables, dimension-reduction methods, and model types) on the accuracy of SDM predictions, with the aim of identifying sources of discrepancy and uncertainty. We found that model type was the major factor causing variation in species-distribution predictions among the various modeling components tested. We also found that different combinations of modeling components could significantly increase or decrease the performance of a model. This result indicated the importance of keeping modeling components constant for comparing a given SDM result. With all modeling components, constant, machine-learning models seem to outperform other model types. We also found that, on average, the Hierarchical Non-Linear Principal Components Analysis dimension-reduction method improved model performance more than other methods tested. We also found that the widely used confusion-matrix-based model-performance indices such as the area under the receiving operating characteristic curve (AUC), sensitivity, and Kappa do not necessarily help select the best model from a set of models if variation in performance is not large. To conclude, model result discrepancies do not necessarily suggest lack of robustness in correlative modeling as they can also occur due to inappropriate selection of modeling components. In addition, more research on model performance evaluation is required for developing robust and sensitive model evaluation methods. Undertaking multi-scenario species-distribution modeling, where possible, is likely to mitigate errors arising from inappropriate modeling components selection, and provide end users with better information on the resulting model prediction uncertainty. Full article

(This article belongs to the Special Issue Invasive Insect Species Modelling and Control)

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50 pages, 10851 KiB

Open AccessArticle

The Phylogenetic Relationships of Tiaronthophagus n.gen. (Coleoptera, Scarabaeidae, Onthophagini) Evaluated by Phenotypic Characters

by Angela Roggero, Philippe Moretto, Enrico Barbero and Claudia Palestrini

Insects 2019, 10(3), 64; https://doi.org/10.3390/insects10030064 - 01 Mar 2019

Cited by 4 | Viewed by 4084

Abstract

A necro-coprophagous new genus tha is widespread in the whole Sub-Saharan Africa was identified within the tribe Onthophagini and named Tiaronthophagus n.gen. The new genus, which is well characterized by an exclusive set of characters, comprises, at present, 26 species. Twenty species were [...] Read more.

A necro-coprophagous new genus tha is widespread in the whole Sub-Saharan Africa was identified within the tribe Onthophagini and named Tiaronthophagus n.gen. The new genus, which is well characterized by an exclusive set of characters, comprises, at present, 26 species. Twenty species were formerly included in the genus Onthophagus and six were identified and here described as new species: Tiaronthophagus angolensis n.sp., T. jossoi n.sp., T. katanganus n.sp., T. rolandoi n.sp., T. saadaniensis n.sp., and T. zambesianus n.sp. A phylogenetic analysis that is based on a combined matrix, including discrete and landmark characters, was done. The landmark characters were tested using the geometric morphometrics techniques before their inclusion in the matrix. One single, fully resolved tree was obtained, with Tiaronthophagus constituting a distinct, monophyletic clade within Onthophagini, which was clearly separated from the other genera examined here. The biogeographical analysis identified the Central Africa as the ancestral area of the new genus and it mainly accounted for dispersal events leading to the present distribution. The generic rank that is assigned to the taxon is supported by the results of the morphological, phylogenetic, and biogeographical analyses, and by the comparison to the outgroups. Full article

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18 pages, 3174 KiB

Open AccessArticle

Field and Laboratory Performance of False Codling Moth, Thaumatotibia Leucotreta (Lepidoptera: Troticidae) on Orange and Selected Vegetables

by Abdullah Mohamed Mkiga, Samira Abuelgasim Mohamed, Hannalene du Plessis, Fathiya Mbarak Khamis and Sunday Ekesi

Insects 2019, 10(3), 63; https://doi.org/10.3390/insects10030063 - 28 Feb 2019

Cited by 19 | Viewed by 4356

Abstract

False codling moth (FCM), Thaumatotibia leucotreta is a key pest of citrus orange and other plants causing fruit loss through larval feeding. Although this pest is native to sub-Saharan Africa little is known on its performance on orange and vegetables in Kenya and [...] Read more.

False codling moth (FCM), Thaumatotibia leucotreta is a key pest of citrus orange and other plants causing fruit loss through larval feeding. Although this pest is native to sub-Saharan Africa little is known on its performance on orange and vegetables in Kenya and Tanzania. Our objective was to assess the incidence, oviposition preference and offspring performance of FCM on orange and vegetables, namely, okra, African eggplant, chili and sweet peppers. A higher percentage of orange with FCM damage symptoms was recorded from the ground than from the tree sampled fruit. However, FCM larval incidence was higher for the latter (tree sampled fruit). The highest FCM larval incidence amongst the vegetables was recorded on African eggplant (12%) while the lowest was on okra (3%). Orange was the most while African eggplant was the least preferred for oviposition by FCM. Among the vegetables tested, strong oviposition preference was found for sweet pepper; however, larval survival was lowest (62%) on this crop. Highest larval survival (77%) was recorded on orange. Most demographic parameters (i.e., intrinsic rate of increase, doubling time) were comparable among the studied host plants. The results are discussed in line of FCM management. Full article

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17 pages, 840 KiB

Open AccessReview

Odonata: Who They Are and What They Have Done for Us Lately: Classification and Ecosystem Services of Dragonflies

by Michael L. May

Insects 2019, 10(3), 62; https://doi.org/10.3390/insects10030062 - 28 Feb 2019

Cited by 40 | Viewed by 10715

Abstract

Odonata (dragonflies and damselflies) are well-known but often poorly understood insects. Their phylogeny and classification have proved difficult to understand but, through use of modern morphological and molecular techniques, is becoming better understood and is discussed here. Although not considered to be of [...] Read more.

Odonata (dragonflies and damselflies) are well-known but often poorly understood insects. Their phylogeny and classification have proved difficult to understand but, through use of modern morphological and molecular techniques, is becoming better understood and is discussed here. Although not considered to be of high economic importance, they do provide esthetic/spiritual benefits to humans, and may have some impact as predators of disease vectors and agricultural pests. In addition, their larvae are very important as intermediate or top predators in many aquatic ecosystems. More recently, they have been the objects of study that have yielded new information on the mechanics and control of insect flight. Full article

(This article belongs to the Special Issue Diversity and Ecosystem Services of Aquatic Insects)

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19 pages, 752 KiB

Open AccessReview

Dynamic Responses of Ground-Dwelling Invertebrate Communities to Disturbance in Forest Ecosystems

by Kayla I. Perry and Daniel A. Herms

Insects 2019, 10(3), 61; https://doi.org/10.3390/insects10030061 - 26 Feb 2019

Cited by 9 | Viewed by 4496

Abstract

In forest ecosystems, natural and anthropogenic disturbances alter canopy structure, understory vegetation, amount of woody debris, and the properties of litter and soil layers. The magnitude of these environmental changes is context-dependent and determined by the properties of the disturbance, such as the [...] Read more.

In forest ecosystems, natural and anthropogenic disturbances alter canopy structure, understory vegetation, amount of woody debris, and the properties of litter and soil layers. The magnitude of these environmental changes is context-dependent and determined by the properties of the disturbance, such as the frequency, intensity, duration, and extent. Therefore, disturbances can dynamically impact forest communities over time, including populations of ground-dwelling invertebrates that regulate key ecosystem processes. We propose conceptual models that describe the dynamic temporal effects of canopy gap formation and coarse woody debris accumulation following disturbances caused by invasive insects, wind, and salvage logging, and their impacts on ground-dwelling invertebrate communities. Within this framework, predictions are generated, literature on ground-dwelling invertebrate communities is synthesized, and pertinent knowledge gaps identified. Full article

(This article belongs to the Special Issue Ecology and Management of Forest Insects in a Changing World)

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10 pages, 204 KiB

Open AccessReview

Termite Ecology in the First Two Decades of the 21st Century: A Review of Reviews

by David E. Bignell

Insects 2019, 10(3), 60; https://doi.org/10.3390/insects10030060 - 26 Feb 2019

Cited by 18 | Viewed by 5261

Abstract

Termite ecology came of age in 1978 with the seminal review of Wood and Sands which by considering the quantitative contributions made by termites to the carbon cycle at the landscape level concluded that they were major players in tropical ecosystems. Subsequent field [...] Read more.

Termite ecology came of age in 1978 with the seminal review of Wood and Sands which by considering the quantitative contributions made by termites to the carbon cycle at the landscape level concluded that they were major players in tropical ecosystems. Subsequent field work in the succeeding two decades was summarised in 2000 by Bignell and Eggleton, the most recent review which attempted to cover the entire topic in detail, which included 188 listed references and has been extensively cited for almost 20 years. Subsequent summaries more narrowly defined or in some cases more superficial are listed in the bibliography. In this overview, the main and subsidiary headings in Bignell and Eggleton are revisited and reclassified in the light of 186 selected articles added to the relevant literature since 2000, and some earlier work. While the literature on termite ecology remains buoyant, it has declined relative to publications on other aspects of termite biology. Overall, the thesis that termites have a major impact on, and are major indicators of soil health and landscape integrity in the tropics and sub-tropics is maintained, but the drivers of local diversity, abundance and biomass remain complex, with many biographical, edaphic and optimum sampling issues not completely resolved. The large increase in diversity and abundance data from Neotropical biomes can also be noted. Full article

(This article belongs to the Special Issue Ecology of Termites)

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Insects, Volume 10, Issue 3 (March 2019) – 24 articles

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