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The effectiveness of eyespots and masquerade in protecting artificial prey across ontogenetic and seasonal shifts

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Current Zoology 2022年第4期68卷 451-458页

作者： Elizabeth G Postema department of entomology and nematology University of CaliforniaDavisCA 95616USA

When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life *** caterpillars in the genus Papilio exhibit unique ontogenetic color sequences:for example,early instars that masquerade as bird feces,with later instars possessing eyespots.I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler *** ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity.I conducted predation experiments with artificial prey to determine how potential signaling constraints(specifically size and season)shape predation risk,and consequently the expression of ontogenetic color change in Papilio ***,both predation and background greenness declined significantly from July to September,though there was little evidence that these patterns impacted the effectiveness of either color *** size and color strongly affected the attack rate of avian predators:attacks increased with prey size regardless of color,and eyespotted prey were attacked more than masquerading prey *** results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey,and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large,eyespotted larvae in nature.

关键词： ontogenetic color change eyespots masquerade predator-prey dynamics season

Transcytosis of Junonia coenia densovirus VP4 across the gut epithelium of Spodoptera frugiperda(Lepidoptera:Noctuidae)

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Insect Science 2020年第1期27卷 22-32页

作者： Mariah Kemmerer Bryony C.Bonning department of entomology Iowa State UniversityAmesIowaUSA department of entomology and nematology University of FloridaGainesvilleFloridaUSA

The Junonia coenia densovirus rapidly traverses the gut epithelium of the host lepidopteran without replicating in the gut *** ability of this virus to transcytose across the gut epithelium is of interest for the potential use of virus structural proteins as delivery vehicles for insecticidal peptides that act within the insect hemocoel,rather than in the *** this study,we used fall armyworm,Spodoptera frugiperda to examine the binding of the virus to brush border membrane vesicle proteins by two-dimensional ligand blot *** also assessed the rate of flux of the primary viral structural protein,VP4 fused to eGFP with a proline-rich linker(VP4-P-eGFP)through the gut epithelium ex vivo in an Ussing *** mechanisms involved with transcytosis of VP4-P-eGFP were assessed by use of *** serum albumin(BSA)and eGFP were used as positive and negative control proteins,*** contrast to BSA,which binds to multiple proteins on the brush border membrane,VP4-P-eGFP binding was specific to a protein of high molecular *** flux was significantly higher for VP4-P-eGFP after 2 h than for albumin or eGFP,with rapid transcytosis of VP4-P-eGFP within the first 30 *** contrast to BSA which transcytosed following clathrin-mediated endocytosis,the movement of VP4-P-eGFP was vesicle-mediated but *** specificity of binding combined with the efficiency of transport across the gut epithelium suggest that VP4 will provide a useful carrier for insecticidal peptides active within the hemocoel of key lepidopteran pests including ***.

关键词： BSA gut epithelium JcDNV Lepidoptera transcytosis virus

Feeding behavior and hormoligosis associated with imidacloprid resistance in Asian citrus psyllid,Diaphorina citri

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Insect Science 2024年第4期31卷 1211-1221页

作者： Xue Dong Chen Justin George Lauren M.Diepenbrock Hunter Gossett Guoping Liu Jawwad A.Qureshi Lukasz L.Stelinski entomology and nematology department University of FloridaCitrus Research and Education CenterLake AlfredFloridaUSA Southern Insect Management Research Unit USDA-ARSStonevilleMississippiUSA entomology and nematology department University of FloridaSouthwest Florida Research and Education CenterImmokaleeFloridaUSA

Imidacloprid is a neonicotinoid insecticide used for managing the Asian citrus psyllid,Diaphorina citri Kuwayama,which serves as vector of phytopathogens causing citrus ***,development of resistance to neonicotinoids among populations of *** has coincided with occasional control failures in the *** objectives of this research were to(1)survey current levels of imidacloprid resistance in Florida citrus;(2)compare feeding behavior between imidacloprid-resistant and susceptible *** using electrical penetration graph recordings,and(3)investigate the possible amplification of insecticide hormoligosis associated with *** surveys confirmed that the susceptibility of *** populations to imidacloprid has decreased in commercial Florida citrus groves compared with a laboratory-susceptible *** 12 generations of selection,resistance to imidacloprid increased by 438 fold compared with the susceptible ***-susceptible *** feeding on citrus exhibited significantly more bouts associated with intercellular pathway(C),phloem penetration(D),phloem salivation(E1),and nonprobing(Np)activities than imidacloprid-resistant ***,there were no differences observed in the frequency or duration of phloem ingestion or xylem feeding between susceptible and resistant *** was no statistical difference in fecundity between resistant and susceptible ***,the fecundity of imidacloprid-susceptible female *** treated with a sublethal concentration of imidacloprid(LC_(25))increased significantly compared with controls,while such hormoligosis was less pronounced among imidacloprid-resistant *** results suggest that imidacloprid-resistant psyllids may cease feeding sooner than susceptible counterparts following sublethal exposure to this insecticide,indicative of a behavioral resistance mechanism.

关键词： artificial selection electrical penetration graph feeding behavior hormoligosis insecticide resistance sublethal exposure

Characterization of the voltage-gated sodium channel of the Asian citrus psyllid, Diaphorina citri

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Insect Science 2017年第1期24卷 47-59页

作者： Bin Liu Monique R. Coy Jin-Jun Wang Lukasz L. Stelinski entomology and nematology department Citrus Research and Education Center University of Florida Florida USA Key Laboratory of entomology and Pest Control Engineering College of Plant Protection Southwest University Chongqing China

The Asian citrus psyllid, Diaphorina citri Kuwayama （Hemiptera： Liviidae）, is an important insect pest of citrus. It is the vector of ＇Candidatus＇ Liberibacter asiaticus, a phloem-limited bacterium that infects citrus, resulting in the disease Huanglongbing （HLB）. Disease management relies heavily on suppression of D. cirri populations with insecticides, including pyrethroids. In recent annual surveys to monitor insecticide resistance, reduced susceptibility to fenpropathrin was identified in several field populations olD. citri. The primary target ofpyrethroids is the voltage-gated sodium channel （VGSC）. The VGSC is prone to target-site insensitivity because of mutations that either reduce pyrethroid binding and/or alter gating kinetics. These mutations, known as knockdown resistance or kdr, have been reported in a wide diversity of arthropod species. Alternative splicing, in combination with kdr mutations, has been also associated with reduced pyrethroid efficacy. Here we report the molecular characterization of the VGSC in D. citri along with a survey of alternative splicing across developmental stages of this species. Previous studies demonstrated that D. citri has an exquisite enzymatic arsenal to detoxify insecticides resulting in reduced efficacy. The results from the current investigation demonstrate that target-site insensitivity is also a potential basis for insecticide resistance to pyrethroids in D. citri. The VGSC sequence and its molecular characterization should facilitate early elucidation of the underlying cause of an established case of resistance to pyrethroids. This is the first characterization of a VGSC from a hemipteran to this level of detail, with the majority of the previous studies on dipterans and lepidopterans.

关键词： citrusgreening diseasemanagement knockdownresistance(kdr) target-site insensitivity

Botanicals, selective insecticides, and predators to control Diaphorina citri （Hemiptera： Liviidae） in citrus orchards

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Insect Science 2014年第6期21卷 717-726页

作者： Azhar A. Khan Muhammad Afzal Jawwad A. Qureshi Arif M. Khan Abubakar M. Raza department of Agricultural entomology University of Sargodha Sargodha Pakistan department of entomology & nematology Southwest Florida Research and Education Center Institute of Food and Agricultural Sciences University of Florida Immokalee Florida USA department of Biotechnology University of Sargodha Sargodha Pakistan

The Asian citrus psyllid （ACP） Diaphorina citri Kuwayama vectors pathogens that cause huanglongbing （HLB） or citrus greening devastating and economically im- portant disease present in most citrus growing regions. Young citrus shoots are required for psyllid reproduction and development. During winter citrus trees produce little or no new growth. Overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. Botanicals and relatively selective insecti- cides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin （Neem）, Tropane （Datura）, Spirotetramat, Spinetoram, and broad- spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old ＂Kinow＂ Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, aver- age 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Ane- glei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides.

关键词： Asian citrus psyllid biopesticides Coccinellids huanglongbing predators

Systemic RNAi in western corn rootworm, Diabrotica virgifera virgifera, does not involve transitive pathways

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Insect Science 2018年第1期25卷 45-56页

作者： Huarong Li Andrew J. Bowling Premchand Gandra Murugesan Rangasamy Heather E. Pence Robert E. McEwan Chitvan Khajuria Blair D. Siegfried Kenneth E. Narva Dow AgroSciences LLC 9330 Zionsville Rd. Indianapolis Indiana USA department of entomology University of Nebraska Lincoln Nebraska USA Monsanto Company Chesterfield Missouri USA entomology and nematology department University of Florida Gainesville Florida USA

Western corn rootworm （WCR, Diabrotica virgifera virgifera LeConte） is highly sensitive to orally delivered double-stranded RNA （dsRNA）. RNAi in WCR is systemic and spreads throughout the insect body. This raises the question whether transitive RNAi is a mechanism that functions in WCR to amplify the RNAi response via production of secondary siRNA. Secondary siRNA production is achieved through RNA-dependent RNA polymerase （RdRP） activity in other eukaryotic organisms, but RdRP has not been identified in WCR and any other insects. This study visualized the spread of the RNAi- mediated knockdown of Dr v-ATPase C mRNA throughout the WCR gut and other tissues using high-sensitivity branched DNA in situ hybridization. Furthermore, we did not detect either secondary siRNA production or transitive RNAi in WCR through siRNA sequence profile analysis. Nucleotide mismatched sequences introduced into either the sense or antisense strand of v-ATPase C dsRNAs were maintained in siRNAs derived from WCR fed with the mismatched dsRNAs in a strand specific manner. The distribution of all siRNAs was restricted to within the original target sequence regions, which may indicate the lack of new dsRNA synthesis leading to production of secondary siRNA. Thus, the systemic spread of RNAi in WCR may be derived from the original dsRNA molecules taken up from the gut lumen. These results indicate that the initial dsRNA dose is important for a lethal systemic RNAi response in WCR and have implications in developing effective dsRNA traits to control WCR and in resistance management to prolong the durability of RNAi trait technology.

关键词： corn rootworm Diabrotica secondary siRNA production systemic RNAi transitive RNAi

Slow-growth high-mortality： A meta-analysis for insects

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Insect Science 2018年第2期25卷 337-351页

作者： Ke-Wei Chen Yigen Chen College of Agriculture South China Agricultural University Guangzhou China department of entomology and nematology University of California One Shields Avenue Davis California US

The slow growth-high mortality hypothesis （SG-HG） predicts that slower growing herbivores suffer greater mortality due to a prolonged window of vulnerability. Given diverse plant-herbivore-natural enemy systems resulting from different feeding ecologies of herbivores and natural enemies, this hypothesis might not always be applicable to all systems. This is evidenced by mixed support from empirical data. In this study, a meta- analysis of the SG-HM hypothesis for insects was conducted, aiming to find conditions that favor or reject SG-HM. The analysis revealed significant within- and between-group heterogeneity for almost a11 explanatory variables and overall did not support SG-HM. In this analysis, SG-HM was supported when any of the following 5 conditions was met：（1） host food consisted of artificial diet; （2） herbivore growth was measured as larval mass; （3） herbivores were generalists; （4） no or multiple species of natural enemies were involved in the study; and （5） parasitoids （i.e., parasitic insects） involved in the study were gregarious. SG-HM was rejected when any of the following 5 conditions was met：（1） herbivores were from the order Hymentoptera; （2） parasitoids from more than 1 order caused herbivore mortality; （2） parasitoids were specialists; （3） parasitoids were solitary; （4） parasitoids were idiobionts or koinobionts; and （5） single species of natural enemy caused mortality of specialist herbivores. All known studies investigated herbivore mortality for a short period of their life cycle. Researchers are encouraged to monitor herbivore mortality during the entire window of susceptibility or life cycle using life tables. Studies involving multiple mortality factors （i.e., both biotic and abiotic） or multiple natural enemy species are also encouraged since herbivores in nature face a multitude of risks during the entire life cycle. More comprehensive studies may increase our understanding of factors influencing the relationships between herbivore gr

关键词： feeding ecology natural enemy parasitoid predator tritrophic interactions

Cold acclimation increases Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae) survival during exposure to freezing temperatures

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Insect Science 2022年第2期29卷 531-538页

作者： Xavier Martini Kathi Malfa Dara Stockton Monique JRivera department of entomology and nematology North Florida Research and Education CenterQuincyFloridaUSA USDA-ARS U.S.Pacific Basin Agricultural Research CenterHiloHawaiiUSA department of entomology University of CaliforniaRiversideCaliforniaUSA

The Asian citrus psyllid,Diaphorina citri,is the vector of the pathogenic bacteria that causes Huanglongbing,the most devasting disease affecting citrus *** cultivation of citrus tends to expand northward,the tolerance of psyllids to freezing temperatures needs to be *** mortality of *** to cold temperature has been previously studied,much less is known regarding the acclimation potential of psyllids to cold *** first evaluated cold resistance of *** depending on color morph and ***,we compared mortality of *** at−4°C for 10 hours between unacclimated psyllids,psyllids that were gradually acclimated to cold over 1 or 2 weeks,and psyllids intermittently acclimated also for 1 or 2 *** did not find major differences in cold resistance between color morphs and *** found that after 1 week of gradual acclimation,the survival of psyllids at−4°C increased to 86%,compared to 20%in the control *** did not increase after the second week of gradual *** intermittent acclimation improved survival compared to the control group,it was less effective than gradual acclimation with a survival at 30%and 70%after 1 and 2 weeks of acclimation,respectively,although this difference with gradual acclimation was not significant at week *** data show that gradual cold acclimation allows *** to survive brief periods below *** may serve as a mechanism responsible for increasing northern establishment of this pest.

关键词： cold acclimation cold hardy citrus cold resistance citrus greening Diaphorina citri overwintering

Anopheles gambiae strain(Ag55)cultured cells originated from Anopheles coluzzii and are phagocytic with hemocyte-like gene expression

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Insect Science 2022年第5期29卷 1346-1360页

作者： Ruchir Mishra Gang Hua Ujwal R.Bagal Donald E.Champagne Michael J.Adang department of entomology College of Agricultural and Environmental SciencesUniversity of GeorgiaAthensGeorgiaUSA department of entomology and nematology University of FloridaGainesvilleFloridaUSA Institute of Bioinformatics University of GeorgiaAthensGeorgiaUSA department of Biochemistry and Molecular Biology University of GeorgiaAthensGeorgiaUSA

Anopheles gambiae and Anopheles coluzzii are closely related species that are predominant vectors of malaria in ***,*** form M was renamed *** and we now conclude on the basis of a diagnostic PCR-restriction fragment length polymorphism assay that Ag55 cells were derived from *** established an Ag55 cell transcriptome,and KEGG pathway analysis showed that Ag55 cells are enriched in phagosome pathway *** Ag55 transcriptome has an abundance of specific transcripts characteristic of mosquito *** *** bioparticle uptake experiments visualized by fluorescence microscopy and confocal microscopy and quantified by flow cytometry establish the phagocytic competence of Ag55 *** from this investigation of Ag55 cell properties will guide researchers in the use and engineering of the Ag55 cell line to better enable investigations of Plasmodium,other microbes,and insecticidal toxins.

关键词： Anopheles coluzzii transcriptome Anopheles gambiae confocal microscopy flow-cytometry FPKM hemocyte-like phagocytosis