Agriculture

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14 pages, 2200 KiB

Open AccessArticle

Population Dynamics and Parasitism of the Kudzu Bug, Megacopta cribraria, by Egg Parasitoid, Paratelenomus saccharalis, in Southeastern USA

by Worrel Diedrick, Lambert H. B. Kanga, Muhammad Haseeb, Mrittunjai Srivastava and Jesusa C. Legaspi

Agriculture 2023, 13(1), 13; https://doi.org/10.3390/agriculture13010013 - 21 Dec 2022

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Abstract

Megacopta cribraria (Fabricius) (Hemiptera: Plataspidae), commonly called the kudzu bug, is a pest of concern in many soybean and legume-producing states. It was first detected in the United States in 2009. In the southeastern United States, M. cribraria reduced crop yields by 47% [...] Read more.

Megacopta cribraria (Fabricius) (Hemiptera: Plataspidae), commonly called the kudzu bug, is a pest of concern in many soybean and legume-producing states. It was first detected in the United States in 2009. In the southeastern United States, M. cribraria reduced crop yields by 47% in untreated soybean fields. Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae) is a known parasitoid of the kudzu bug, and a potential biological control agent. This study was comprised of three phases: (1) Preliminary assessment of the presence of the kudzu bug and its parasites in north Florida and south Georgia. (2) Measurements of the levels of parasitism in 12 sites selected from the preliminary evaluation to compare population dynamics in two growing seasons in agricultural, forested, and urban areas. (3) Laboratory studies to measure parasitism after 21 days in controlled environments. The preliminary assessment showed that in both 2016 and 2017, P. saccharalis emerged from eggs of M. cribraria collected in Leon and Gadsden County. Additionally, parasitism was recorded for the recently discovered egg parasitoid in north Florida, Ooencyrtus nezarae (Ishii) (Hymenoptera: Encyrtidae). In the assessment of parasitism in the field, differences were observed in the average level of parasitism within the urban and forest area in both years, and in the agricultural area for 2017. Between-group comparisons indicated significant differences between the average parasitism levels in agricultural, urban, and forested areas in 2016; in 2017, the differences between the areas were not significant. In the laboratory, after 21 days of observation, an average of 77.4% of freshly laid and 61.6% of cooled eggs were parasitized by P. saccharalis, and adult parasitoids emerged. There was a significant difference in the emergence of freshly laid eggs over cooled eggs. This study suggests that both P. saccharalis and O. nezarae exert some levels of natural control of the kudzu bug in the field and may be useful as biological control agents in an integrated pest management program. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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12 pages, 1551 KiB

Open AccessArticle

Survival and Feeding Behavior of Diaphorina citri (Hemiptera: Liviidae) Adults on Common Cover Crops in Citrus

by Justin George, Ramdas Kanissery, Mahesh Bashyal, Blessy Tamayo and Lukasz L. Stelinski

Agriculture 2022, 12(12), 2175; https://doi.org/10.3390/agriculture12122175 - 19 Dec 2022

Cited by 1 | Viewed by 1919

Abstract

Asian citrus psyllid, Diaphorina citri, transmits Candidatus Liberibacter asiaticus (CLas), the bacterial pathogen responsible for citrus greening disease. To explore the possibility that cover crops in citrus groves may serve as refuges for this pathogen vector during unfavorable host conditions, [...] Read more.

Asian citrus psyllid, Diaphorina citri, transmits Candidatus Liberibacter asiaticus (CLas), the bacterial pathogen responsible for citrus greening disease. To explore the possibility that cover crops in citrus groves may serve as refuges for this pathogen vector during unfavorable host conditions, psyllid feeding was investigated on six common cover crop species and citrus using electrical penetration graph (EPG) recordings and behavioral bioassays. EPG recordings showed that the proportion of time spent by D. citri feeding on xylem was similar or higher on all tested cover crops (17%–32%) compared to the positive control (12%), the preferred host, Citrus macrophylla. Very little to no phloem feeding was observed on cover crops by the adults. In the choice assays, more D. citri adults settled on buckwheat (Fagopyrum esculentum) and cowpea (Vigna unguiculata) than on the host, C. macrophylla, 24 h after release. No-choice assays showed that the citrus cover crop species evaluated extend the survival of D. citri up to 8 d because of xylem feeding. Our results indicate that some cover crop species may be less suitable refuge sites for D. citri than others, but none served as breeding sites or supported more than 8 d of survival. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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14 pages, 2837 KiB

Open AccessArticle

Symbiotic and Antagonistic Functions of the Bacterium Burkholderia cepacia BsNLG8, from the Nilaparvata lugens (Stal)

by Xuemei Wang, Rongrong Yang, Junaid Zafar, Chen Peng, Xuewei Zhang, Yingying Hong, Surajit De Mandal, Wenqing Zhang, Fengliang Jin and Xiaoxia Xu

Agriculture 2022, 12(12), 2106; https://doi.org/10.3390/agriculture12122106 - 08 Dec 2022

Viewed by 1354

Abstract

Bacterial symbionts are widespread in insects and other animals. These microbes play crucial roles in many aspects of insect physiology and biology, including immunity, nutrition and confronting plant defenses. In the present study, we isolated and identified the bacterium Burkholderia cepacia BsNLG8 from [...] Read more.

Bacterial symbionts are widespread in insects and other animals. These microbes play crucial roles in many aspects of insect physiology and biology, including immunity, nutrition and confronting plant defenses. In the present study, we isolated and identified the bacterium Burkholderia cepacia BsNLG8 from the brown planthopper (BPHs), Nilaparvata lugens, a devastating pest of rice crops worldwide. Plate confrontation assay indicated that BsNLG8 significantly inhibited the growth of phytopathogenic fungi. In addition, the BsNLG8 strain demonstrated the ability to produce siderophores, which explains its antagonistic mechanism. Lastly, we explored the nicotine degradation ability of BsNLG8 using in vitro and in vivo methods. In vitro, HPLC analysis results showed that BsNLG8 could significantly reduce the concentration of nicotine in the medium at 36 h. Moreover, microinjection of BsNLG8 in axenic BPHs increased the survival rate of the host on nicotine-containing rice seedlings. These findings could serve as the basis of future research in deciphering the interaction between host and symbionts. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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27 pages, 3591 KiB

Open AccessArticle

Direct and Indirect Effects of Planting Density, Nitrogenous Fertilizer and Host Plant Resistance on Rice Herbivores and Their Natural Enemies

by Finbarr G. Horgan, Eduardo Crisol-Martínez, Alexander M. Stuart, James M. Villegas, Ainara Peñalver-Cruz, Enrique A. Mundaca, Marivic O. Perez, Carmencita C. Bernal, Maria Liberty P. Almazan and Angelee F. Ramal

Agriculture 2022, 12(12), 2053; https://doi.org/10.3390/agriculture12122053 - 30 Nov 2022

Cited by 3 | Viewed by 1770

Abstract

In rice ecosystems, seeding densities can be adjusted to compensate for lower nitrogen levels that reduce GHG emissions, or to increase farm profitability. However, density-induced changes to plant anatomy could affect herbivore-rice interactions, and alter arthropod community dynamics. We conducted an experiment that [...] Read more.

In rice ecosystems, seeding densities can be adjusted to compensate for lower nitrogen levels that reduce GHG emissions, or to increase farm profitability. However, density-induced changes to plant anatomy could affect herbivore-rice interactions, and alter arthropod community dynamics. We conducted an experiment that varied transplanting density (low or high), nitrogenous fertilizer (0, 60 or 150 kg added ha⁻¹) and rice variety (resistant or susceptible to phloem-feeding insects) over two rice-growing seasons. Yields per plot increased with added nitrogen, but were not affected by variety or transplanting density. Planthopper and leafhopper densities were lower on resistant rice and in high-density field plots. Nitrogen was associated with higher densities of planthoppers, but lower densities of leafhoppers per plot. High planting densities and high nitrogen also increased rodent damage. The structure of arthropod herbivore communities was largely determined by season and transplanting density. Furthermore, two abundant planthoppers (Sogatella furcifera (Horváth) and Nilaparvata lugens (Stål)) segregated to low and high-density plots, respectively. The structure of decomposer communities was determined by season and fertilizer regime; total decomposer abundance increased in high-nitrogen plots during the dry season. Predator community structure was determined by season and total prey abundance (including decomposers) with several spider species dominating in plots with high prey abundance during the wet season. Our results indicate how rice plasticity and arthropod biodiversity promote stability and resilience in rice ecosystems. We recommend that conservation biological control, which includes a reduction or elimination of insecticides, could be promoted to attain sustainable rice production systems. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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13 pages, 2453 KiB

Open AccessArticle

Effects of Inhibiting the Expression of Chitin Synthase Gene SfCHSB on the Metabolism of Trehalose and Chitin in Spodoptera frugiperda Larvae

by Xiangyu Liu, Shasha Wang, Yuanyi Yu, Yisha Cheng, Chaoxing Hu, Min Zhou, Can Li, Bin Tang and Yan Wu

Agriculture 2022, 12(12), 2019; https://doi.org/10.3390/agriculture12122019 - 26 Nov 2022

Cited by 2 | Viewed by 1562

Abstract

Spodoptera frugiperda is one of the world’s major agricultural pests and it occurs in many countries around the world. In Lepidoptera, the peritrophic membrane in the midgut protects the midgut epithelial cells and facilitates the digestion and absorption of food. Its main components [...] Read more.

Spodoptera frugiperda is one of the world’s major agricultural pests and it occurs in many countries around the world. In Lepidoptera, the peritrophic membrane in the midgut protects the midgut epithelial cells and facilitates the digestion and absorption of food. Its main components are chitin and protein. Chitin synthase (CHS), as the last enzyme in the chitin biosynthesis pathway, is very important. Here, the expression of chitin synthase B (CHSB) gene identified from midgut was inhibited by RNA interference to explore its function in the metabolism of trehalose and chitin of S. frugiperda larvae. The results were as follows: SfCHSB was highly expressed in actively feeding larvae. Second, knockdown of SfCHSB resulted in decreased expression of most genes involved in chitin metabolism, including chitinase, and abnormal phenotypes of S. frugiperda were observed. In addition, membrane-bound trehalase activity and glucose content increased, and trehalose content decreased at 24 h after dsSfCHSB injection. Trehalase activities increased significantly and the glycogen content decreased at 48 h after dsSfCHSB injection. Finally, the activity of chitinase decreased and the content of chitin increased significantly. Our results indicate that SfCHSB expression is specific, SfCHSB has a large role in regulating chitin metabolism, and it has broad application prospects in the biocontrol of S. frugiperda. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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8 pages, 628 KiB

Open AccessArticle

Effects of Host Ages and Release Strategies on the Performance of the Pupal Parasitoid Spalangia endius on the Melon Fly Bactrocera cucurbitae

by Jian-Feng Liu, Cheng-Xu Wu, Atif Idrees, Hai-Yan Zhao and Mao-Fa Yang

Agriculture 2022, 12(10), 1629; https://doi.org/10.3390/agriculture12101629 - 07 Oct 2022

Cited by 2 | Viewed by 1374

Abstract

The melon fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), is a quarantine pest that causes considerable economic losses to growers of vegetables and fruits worldwide. Spalangia endius (Walker) (Hymenoptera: Pteromalidae) is a solitary pupal parasitoid of various dipteran hosts. We assessed the impact of [...] Read more.

The melon fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), is a quarantine pest that causes considerable economic losses to growers of vegetables and fruits worldwide. Spalangia endius (Walker) (Hymenoptera: Pteromalidae) is a solitary pupal parasitoid of various dipteran hosts. We assessed the impact of the host pupal age (2, 4, and 6 days old), host density (5, 10, 15, 20, 25, and 30), and parasitoid density (1, 2, 3, 4, 5, and 6) on the parasitizing potential of S. endius on B. cucurbitae pupae under laboratory conditions. The effects of different soil depths on the parasitism rate of S. endius and the dispersal behavior of S. endius at distances of 0, 5, and 10 m were also evaluated under field conditions. The results showed that the parasitism rate of S. endius significantly increased with the increase in host density and parasitoid density. The host pupal age did not influence the number of pupae parasitized by S. endius and the progeny sex ratio of S. endius under different host densities. In the fields, different puparium burial depths of B. dorsalis pupae significantly influenced the parasitism and eclosion rates of S. endius but did not influence the eclosion rate of B. cucurbitae. Spalangia endius females could travel up to 10 m to parasitize at a similar rate on B. cucurbitae pupae compared to S. endius placed at 0 m. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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10 pages, 867 KiB

Open AccessCommunication

Potential of Silicon to Improve Biological Control of Fall Armyworm, Spodoptera frugiperda on Maize

by Kennedy J. Zimba, Quentin D. Read, Muhammad Haseeb, Robert L. Meagher and Jesusa C. Legaspi

Agriculture 2022, 12(9), 1432; https://doi.org/10.3390/agriculture12091432 - 09 Sep 2022

Cited by 2 | Viewed by 1418

Abstract

Silicon (Si) accumulation in plants confers a mechanical barrier to insect herbivory and may alter plant chemistry to increase the attraction of natural enemies to host insect herbivores on Si−treated plants. The fall armyworm (FAW), Spodoptera frugiperda, is a major insect pest [...] Read more.

Silicon (Si) accumulation in plants confers a mechanical barrier to insect herbivory and may alter plant chemistry to increase the attraction of natural enemies to host insect herbivores on Si−treated plants. The fall armyworm (FAW), Spodoptera frugiperda, is a major insect pest of grain crops, including maize (Zea mays L.). This study examined whether Si supplementation alters maize volatile compounds that mediate host location in Euthyrhynchus floridanus, a generalist predator of FAW. A four-arm olfactometer was used to test the olfactory preference of nymphs and adults of E. floridanus to the odor of maize leaf materials from plants that were; Si−treated and infested, Si−treated without infestation, Si−deprived and infested, and Si−deprived without infestation. The probabilities of individual insects choosing between the four treatments were estimated using a multinomial generalized linear mixed model. There were no statistical differences in the olfactory preference of E. floridanus between Si−treated and Si−deprived maize leaf materials. However, the median estimate showed that nymphs were almost twice likely to be attracted to Si−supplemented leaf material, indicating a potential positive effect of Si. However, a more robust follow-up study is needed to further assess the impact of Si on E. floridanus. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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7 pages, 1134 KiB

Open AccessCommunication

The Metarhizium anisopliae Strains Expressing dsRNA of the NlCHSA Enhance Virulence to the Brown Planthopper Nilaparvata lugens

by Jun Hu, He Cui, Mingsheng Hong, Yuxian Xia and Wenqing Zhang

Agriculture 2022, 12(9), 1393; https://doi.org/10.3390/agriculture12091393 - 05 Sep 2022

Cited by 2 | Viewed by 1604

Abstract

Metarhizium anisopliae is a broad-spectrum entomopathogenic fungus with large-scale applications in pest control; however, its slow-killing action is a limiting factor. To enhance fungal virulence, we constructed transgenic M. anisopliae strains that expressed dsRNA targeting the chitin synthase gene A in the brown [...] Read more.

Metarhizium anisopliae is a broad-spectrum entomopathogenic fungus with large-scale applications in pest control; however, its slow-killing action is a limiting factor. To enhance fungal virulence, we constructed transgenic M. anisopliae strains that expressed dsRNA targeting the chitin synthase gene A in the brown planthopper Nilaparvata lugens (NlCHSA). The transcription of NlCHSA was suppressed in N. lugens infected by transgenic M. anisopliae strains. Consequently, the cumulative mortality of N. lugens caused by those transgenic strains was increased by 34.7–40.0% on day 6 after inoculation, and their median lethal times (LT₅₀) were about 50% compared to the wild-type strain. Our results demonstrate that dsRNA expression in M. anisopliae caused RNA silencing in the host insect after infection and hence greatly enhanced the fungal virulence, highlighting a new strategy for augmentation of fungal virulence against sucking pests. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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10 pages, 2080 KiB

Open AccessArticle

RNAi Suppression of Hormone Receptor HR3 Blocks Larval Molting and Metamorphosis in the Cigarette Beetle, Lasioderma serricorne

by Li-Xin Ma, Rong-Tao He, Shu-Yan Yan and Wen-Jia Yang

Agriculture 2022, 12(8), 1257; https://doi.org/10.3390/agriculture12081257 - 18 Aug 2022

Cited by 2 | Viewed by 1540

Abstract

Hormone receptor 3 (HR3), an early-late gene of the 20-hydroxyecdysone (20E) signaling pathway, plays a critical role in insect metamorphosis and development. In this study, we identified and characterized an HR3 gene (LsHR3) from the cigarette beetle, Lasioderma serricorne. The open [...] Read more.

Hormone receptor 3 (HR3), an early-late gene of the 20-hydroxyecdysone (20E) signaling pathway, plays a critical role in insect metamorphosis and development. In this study, we identified and characterized an HR3 gene (LsHR3) from the cigarette beetle, Lasioderma serricorne. The open reading frame of LsHR3 is 1581 bp encoding a 527 amino acid protein that contains a conserved DNA binding domain and a ligand binding domain. LsHR3 was mainly expressed in the fourth-instar larvae, prepupae, and pupae and showed high expression in the fat body. The expression of LsHR3 was induced by 20E, while it was significantly suppressed by silencing of six 20E synthesis and signaling pathway genes. RNA interference (RNAi)-aided knockdown of LsHR3 in the fourth-instar larvae disrupted the larval–pupal molting and caused 100% mortality. The 20E titer of LsHR3-depletion larvae was decreased, and expressions of five 20E synthesis genes were dramatically decreased. Silencing LsHR3 reduced chitin content and downregulated the expression of genes involved in chitin synthesis and degradation. Hematoxylin and eosin staining of abdominal cuticle showed that no apolysis occurred after silencing LsHR3. These results suggest that LsHR3-mediated 20E signaling is involved in the regulation of chitin metabolism during the molting process of L. serricorne, and targeting this gene by RNAi has potential in controlling this pest. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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11 pages, 2291 KiB

Open AccessArticle

Changes in the Physiological Adaptation and Regulation Ability in Harmonia axyridis under Chlorpyrifos and Imidacloprid Stress

by Guoyong Li, Xiaoli Ni, Meikun Liu, Bing Tang, Can Li and Yangyang Liu

Agriculture 2022, 12(8), 1134; https://doi.org/10.3390/agriculture12081134 - 31 Jul 2022

Viewed by 1371

Abstract

As the dominant natural enemy of aphids, Harmonia axyridis plays a crucial role in integrated pest control (IPM) in agro-ecosystems. In order to study the physiological adaptation and regulation ability of Harmonia axyridis to insecticides under chemical pesticide stress, ladybirds were treated with [...] Read more.

As the dominant natural enemy of aphids, Harmonia axyridis plays a crucial role in integrated pest control (IPM) in agro-ecosystems. In order to study the physiological adaptation and regulation ability of Harmonia axyridis to insecticides under chemical pesticide stress, ladybirds were treated with organophosphorus chlorpyrifos (chlorpyrifos) and new nicotine imidacloprid (imidacloprid) to explore the physiological adaptability of ladybirds under chemical pesticide stress by activating trehalose metabolism. The results showed that the imidacloprid affect the larvae develop to pupate, resulted in the H. axyridis died and significantly increased the food consumption of Harmonia axyridis, while the chlorpyrifos prolong the development period of pupae significantly and decreased significantly the food intake of H. axyridis fed with aphids treated with chlorpyrifos. It was further found that Chlorpyrifos could inhibit the activity of the trehalase, while the trehalase activity increased under imidacloprid stress, but both insecticides could decrease the trehalose content. The TRE and TPS genes of Harmonia axyridis under chlorpyrifos and imidacloprid stress were upregulated or downregulated. These relevant results can provide a strong reference for the rational use of chemical pesticides or biological pesticides to control pests in the future. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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12 pages, 6706 KiB

Open AccessArticle

Alternately Rearing with Susceptible Variety Can Delay the Virulence Development of Insect Pests to Resistant Varieties

by Gu Gong, Yu-Dan Zhang, Zhen-Fei Zhang and Wei-Jian Wu

Agriculture 2022, 12(7), 991; https://doi.org/10.3390/agriculture12070991 - 09 Jul 2022

Cited by 2 | Viewed by 1349

Abstract

Resistant crop varieties can usually decrease the population density of insect pests; however, they can also easily cause the occurrence of highly virulent pest populations when repeatedly grown. Whether herbivorous insects feeding intermittently on a susceptible variety affects their subsequent virulence has rarely [...] Read more.

Resistant crop varieties can usually decrease the population density of insect pests; however, they can also easily cause the occurrence of highly virulent pest populations when repeatedly grown. Whether herbivorous insects feeding intermittently on a susceptible variety affects their subsequent virulence has rarely been investigated. In this paper, we examined the variations in the virulence of the brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), by alternately rearing three resistant rice varieties, Mudgo, ASD7, and Rathu Heenati, with a susceptible rice variety (TN1) in indoor experiments. The results showed that, while the susceptible rice variety was used in alternate rearing for several generations, the BPHs exhibited a higher intrinsic rate of increase (r_m) and were identified as less virulent to all three resistant varieties. Such virulence reduction by experience with a susceptible variety could delay the progression of resistance-breaking toward resistant varieties. The results suggested that careful alternation with susceptible varieties in fields is a potential method for pest variety-resistance management. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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7 pages, 411 KiB

Open AccessCommunication

First Report on Voracity and Feeding Preference of Predatory Beetle, Thalassa montezumae (Coleoptera: Coccinellidae) on Croton Scale, Phalacrococcus howertoni (Hemiptera: Coccidae)

by Netalie Francis, Lambert H. B. Kanga, Catharine M. Mannion, Muhammad Haseeb, Anthony Ananga and Jesusa Crisostomo Legaspi

Agriculture 2022, 12(7), 990; https://doi.org/10.3390/agriculture12070990 - 09 Jul 2022

Viewed by 1206

Abstract

The croton scale Phalacrococcus howertoni Hodges & Hodgson gen. nov., sp. nov. (Hemiptera: Coccidae), was first found in Florida, USA. This scale has become a pest because of its high reproductive rate and production of sooty mold. Here, we evaluated predation potential of [...] Read more.

The croton scale Phalacrococcus howertoni Hodges & Hodgson gen. nov., sp. nov. (Hemiptera: Coccidae), was first found in Florida, USA. This scale has become a pest because of its high reproductive rate and production of sooty mold. Here, we evaluated predation potential of the predatory beetle, Thalassa montezumae Mulsant (Coleoptera: Coccinellidae), as a biological control agent. To our knowledge, this is the first study of predation by T. montezumae on P. howertoni. Results of our studies showed that the predation by 4th instar T. montezumae was higher on 2nd stage nymphs than on 3rd stage nymphs P. howertoni; predation on adults was lowest. Mean consumption by adult T. montezumae was highest on 2nd stage nymphs followed by 3rd stage nymphs, and adult P. howertoni. There were no significant differences between male and female adult T. montezumae in the prey first visited when offered a choice of 2nd or 3rd instar nymphs, or adults of P. howertoni. Thus, the levels of acceptance did not vary significantly between stages of prey visited by the males and females. Females chose prey faster than males and used less energy to search for food. Egg fecundity did not vary among female beetles fed with different stages of croton scales. Should P. howertoni become a major pest, T. montezumae could be used as a biological control agent within a biologically based integrated pest management program. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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12 pages, 2026 KiB

Open AccessArticle

The Endogenous Metabolic Response of Tribolium castaneum under a High Concentration of CO₂

by Min Zhou, Xinyu Zhang, Biying Pan, Jiaqi Zhu, Xiaoxiao Qian, Xian Li, Kangkang Xu, Bin Tang and Can Li

Agriculture 2022, 12(7), 979; https://doi.org/10.3390/agriculture12070979 - 07 Jul 2022

Cited by 3 | Viewed by 1441

Abstract

High carbon dioxide concentrations can effectively control most storage pests. To estimate the toxicity effect of high concentrations of CO₂, four different concentrations of CO₂ (25% CO₂, 50% CO₂, 75% CO₂, and 95% CO [...] Read more.

High carbon dioxide concentrations can effectively control most storage pests. To estimate the toxicity effect of high concentrations of CO₂, four different concentrations of CO₂ (25% CO₂, 50% CO₂, 75% CO₂, and 95% CO₂) were used to treat Tribolium castaneum, and the biochemical (carbohydrate content and gene expression level) and physiological (mortality, pupation, eclosion rate, and weight) features of insects submitted to different treatments with CO₂ were evaluated. The T. castaneum mortality rate was 50% in approximately 2 days when exposed to a treatment with 95% CO₂. When the CO₂ concentration exceeded 75%, the pupation rate and eclosion rate of T. castaneum seriously declined. Higher than 25% CO₂ concentrations resulted in a lower weight and shrunken body size of T. castaneum. It was further found that different CO₂ concentration treatments all influenced the levels of the three carbohydrate contents in T. castaneum. In addition, according to the detection of trehalose metabolism pathway-related genes, T. castaneum mainly responds to stress factors via high expression of TPS, TRE1-2, and TRE1-3. Our results enrich the evaluation of the toxicity effect of CO₂ treatment on grain storage pests, providing a basis for further improving the method of regulating grain storage to control insect pests. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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19 pages, 7134 KiB

Open AccessArticle

Multigenerational Effects of Short-Term High Temperature on the Development and Reproduction of the Zeugodacus cucurbitae (Coquillett, 1899)

by Bei Zeng, Yuyang Lian, Jingjing Jia, Yang Liu, Aqiang Wang, Heming Yang, Jinlei Li, Shuyan Yang, Sihua Peng and Shihao Zhou

Agriculture 2022, 12(7), 954; https://doi.org/10.3390/agriculture12070954 - 30 Jun 2022

Cited by 3 | Viewed by 1469

Abstract

Zeugodacus cucurbitae is an important pest of fruit and vegetable crops in tropical and subtropical regions, and high-temperature stress can have different effects on the development and reproduction of successive generations of Z. cucurbitae. To clarify the multigenerational effects of short-time high [...] Read more.

Zeugodacus cucurbitae is an important pest of fruit and vegetable crops in tropical and subtropical regions, and high-temperature stress can have different effects on the development and reproduction of successive generations of Z. cucurbitae. To clarify the multigenerational effects of short-time high temperature on the development and reproduction of Z. cucurbitae, the newly emerged adults of the contemporary (F₁ generation) and the next generation (F₂ generation) were exposed to short-term high temperatures of 25 °C, 33 °C, 37 °C, 41 °C, and 45 °C for 1 h, and the multigenerational (F₁, F₂, and F₃ generation) effects of these temperatures on the development and reproduction of Z. cucurbitae were evaluated. The results showed that (1) when the F₁ was exposed to short-term high temperature, the egg production and lifespan of the F₁ decreased continuously with the increasing temperature, except for the 45 °C treatment for 1 h, which stimulated egg production. Only the 41 °C group had significantly higher egg production and lifespan than the control group in the F₃. (2) In the F₁ and F₂ that were exposed to short-term high temperature, the F₁ and F₃ were consistent with the results of F₁ that were exposed to short-term high temperature. In conclusion, the effects of high-temperature intensity and frequency on multiple generations of Z. cucurbitae were different. The results of this study can elucidate the effects of short-term high-temperature stress on the growth, development, and reproduction of Z. cucurbitae in different generations, and provide a reference basis for the integrated control of Z. cucurbitae. Full article

(This article belongs to the Special Issue Insect Ecology and Pest Management in Agriculture)

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