Entomology Commons^™

Twenty Three True Bug State Records For Arkansas, With Two For Ohio, U.S.A., S. W. Chordas Iii, R. Tumlison, H. W. Robison, J. Kremers

Journal of the Arkansas Academy of Science

No abstract provided.

Phenology Of Stable Fly (Diptera: Muscidae) Larvae In Round Bale Hay Feeding Sites In Eastern Nebraska, David B. Taylor, Dennis R. Berkebile

Department of Entomology: Faculty Publications

The temporal and spatial patterns of adult stable fly, Stomoxys calcitrans (L.), emergence from six sites where large round baled hay had been provided to pasture cattle as winter feed were studied using emergence traps. The substrate at these sites, consisting of waste hay mixed with bovine manure and urine, provided an excellent developmental habitat for immature stable flies. Stable flies were the most frequently collected fly emerging from these sites with a yearly average of 1,581 emerging per square meter. Stable fly emergence from these sites began in early May (235 annual accumulated Day-Degree 10°C [DD₁₀]), peaked …

Dose–Response Relationships Of Clothianidin, Imidacloprid, And Thiamethoxam To Blissus Occiduus (Hemiptera: Blissidae), M. D. Stamm, Frederick P. Baxendale, Tiffany Heng-Moss, Blair D. Siegfried, Erin E. Blankenship, Roch E. Gaussoin

Department of Entomology: Faculty Publications

The western chinch bug, Blissus occiduus Barber (Hemiptera: Blissidae), has emerged as a serious pest of buffalograss, Buchloë dactyloides (Nuttall) Engelmann. In general, neonicotinoid insecticides effectively control a variety of turfgrass insects, particularly phloem-feeding pests. However, because of well documented inconsistencies in control, these compounds are generally not recommended for chinch bugs. This study was designed to document the contact and systemic toxicity of three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) to B. occiduus. In contact bioassays, thiamethoxam was ~20-fold less toxic than clothianidin or imidacloprid to B. occiduus nymphs and three-fold more toxic to adults. In adult systemic …

Genetic Variation And Inheritance Of Diapause Induction In Two Distinct Voltine Ecotypes Of Ostrinia Nubilalis (Lepidoptera: Crambidae), Cengis Ikten, Steven R. Skoda, Thomas E. Hunt, Jaime Molina-Ochoa, John E. Foster

Department of Entomology: Faculty Publications

European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), displays a larval diapause in response to short photoperiods and is adapted to a variety of local conditions throughout North America. Hence, the effective photoperiod inducing larval diapause will differ among geographic ecotypes. This study considers the inheritance of photoperiodic larval diapause induction by hybridization and backcrossing two latitudinally distinct ecotypes of the European corn borer collected between 41° N, 96° W and 48° N, 96° W and under a range of photoperiods representative of their respective locations: from 14:10 to 16:8 (L:D) h. The ecotype adapted to a bivoltine habitat (southeastern …

Field Introgression Of Diabrotica Barberi And Diabrotica Longicornis (Coleoptera: Chrysomelidae) Based On Genetic And Morphological Characters, Laura A. Campbell, Thomas L. Clark, Pete L. Clark, Lance Meinke, John E. Foster

Department of Entomology: Faculty Publications

Diabrotica barberi Smith & Lawrence and Diabrotica longicornis (Say) (Coleoptera: Chrysomelidae) are considered to be sister species, and it has been proposed that the two species may hybridize under field conditions. The objective of this study was to examine genetic and morphological characters of D. barberi and D. longicornis for evidence of field introgression. Both species were collected from sympatric and allopatric areas. Amplified fragment length polymorphisms and morphological characters (color and head capsule width) were used to examine variation within and among populations of D. barberi and D. longicornis. Relatively little of the overall …

Evaluation Of Buffalograss Leaf Pubescence And Its Effect On Resistance To Mealybugs (Hemiptera: Pseudococcidae), Jennifer M. Johnson-Cicalese, Frederick P. Baxendale, Terrance P. Riordan, Tiffany Heng-Moss, Lisa Baird

Department of Entomology: Faculty Publications

Considerable progress has been made in improving the turfgrass characteristics of buffalograss, Buchloë dactyloides (Nutt) Engelm, a native North American grass species with low maintenance requirements (Riordan et al., 1993). Two mealybugs, Tridiscus sporoboli (Cockerell) and Trionymus sp. (Hemiptera: Pseudococcidae) have emerged as buffalograss pests (Baxendale et al., 1994). Mealybugs have been associated with buffalograss stands throughout Nebraska (Baxendale et al., 1994), as well as in Texas and Arizona. Unfortunately, the Pseudococcidae are poorly described and species identification requires extensive specimen preparation (Ferris, 1950, 1953). Buffalograss mealybugs have an oblong, pale purple-grey, membranous body, ranging in length from 0.2 …

Contact And Fumigant Toxicity Of A Botanical-Based Feeding Deterrent Of The Stable Fly, Stomoxys Calcitrans (Diptera: Muscidae), Junwei J. Zhu, Andrew Y. Li, Sara Pritchard, Khanobporn Tangtrakulwanich, Frederick P. Baxendale, Gary Brewer

Department of Entomology: Faculty Publications

The stable fly, Stomoxys calcitrans (L.), has been considered one of the most serious biting flies of confined and pastured livestock. The economic losses caused by the stable fly to the cattle industry in the United States exceed $2 billion annually. Current practices for managing stable flies using insecticides provide only marginal control. Insecticide resistance has also been recently reported in stable flies. The present study reports the use of plant-based insecticides, for example, essential oils, as alternatives for managing this fly pest. The toxicity of several plant essential oils and selected ingredient compounds was evaluated by contact and fumigant …

A Single Major Qtl Controls Expression Of Larval Cry1f Resistance Trait In Ostrinia Nubilalis (Lepidoptera: Crambidae) And Is Independent Of Midgut Receptor Genes, Brad S. Coates, Douglas V. Sumerford, Miriam D. Lopez, Haichuan Wang, Lisa M. Fraser, Jeremy A. Kroemer, Terrence Spencer, Kyung S. Kim, Craig A. Abel, Richard L. Hellmich, Blair D. Siegfried

Department of Entomology: Faculty Publications

The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn and reduces yield of food, feed, and biofuel materials. The Cry1F toxin from Bacillus thuringiensis (Bt) expressed in transgenic hybrid corn is highly toxic to O. nubilalis larvae and effective in minimizing feeding damage. A laboratory colony of O. nubilalis was selected for high levels of Cry1F resistance ([12,000-fold compared to susceptible larvae) and is capable of survival on transgenic hybrid corn. Genetic linkage maps with segregating AFLP markers show that the Cry1F resistance trait is controlled by …

Comparative Susceptibility Of Ostrinia Furnacalis, Ostrinia Nubilalis, And Diatraea Saccharalis (Lepidoptera: Crambidae) To Bacillus Thuringiensis Cry1 Toxins, S. Y. Tan, B. F. Cayabyab, E. P. Alcantara, Y. B. Ibrahim, Fangneng Huang, Erin E. Blankenship, Blair D. Siegfried

Department of Entomology: Faculty Publications

Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) are highly effective against the European corn borer, Ostrinia nubilalis (Hübner), and the closely related Asian corn borer, Ostrinia furnacalis (Guenée). Since the registration of Bt corn hybrids in the U.S. in 1996, there has been a great deal of information generated on O. nubilalis. However, relatively little information exists for O. furnacalis. To help determine whether the information generated for O. nubilalis can be leveraged for decisions regarding the use of transgenic Bt corn against O. furnacalis, experiments were designed to determine whether the pattern of sensitivity …

Characterization Of Olfactory Sensilla Of Stomoxys Calcitrans And Electrophysiological Responses To Odorant Compounds Associated With Hosts And Oviposition Media, K. Tangtrakulwanich, Han Chen, Frederick P. Baxendale, Gary J. Brewer, J. J. Zhu

Department of Entomology: Faculty Publications

Stable flies, Stomoxys calcitrans L. (Diptera: Muscidae), are economically important biting flies that have caused billions of dollars in losses in the livestock industry. Field monitoring studies have indicated that olfaction plays an important role in host location. To further our understanding of stable fly olfaction, we examined the antennal morphology of adults using scanning electron microscopy techniques. Four major types of sensillum were found and classified as: (a) basiconic sensilla; (b) trichoid sensilla with three subtypes; (c) clavate sensilla, and (d) coeloconic sensilla. No significant differences between male and female flies in abundances (total numbers) of these sensillum types …

Identification Of A Novel Aminopeptidase P-Like Gene (Onapp) Possibly Involved In Bt Toxicity And Resistance In A Major Corn Pest (Ostrinia Nubilalis), Chitvan Khajuria, Lawrent L. Buschman, Ming-Shun Chen, Blair D. Siegfried, Kun Yan Zhu

Department of Entomology: Faculty Publications

Studies to understand the Bacillus thuringiensis (Bt) resistance mechanism in European corn borer (ECB, Ostrinia nubilalis) suggest that resistance may be due to changes in the midgut-specific Bt toxin receptor. In this study, we identified 10 aminopeptidase-like genes, which have previously been identified as putative Bt toxin receptors in other insects and examined their expression in relation to Cry1Ab toxicity and resistance. Expression analysis for the 10 aminopeptidase-like genes revealed that most of these genes were expressed predominantly in the larval midgut, but there was no difference in the expression of these genes in Cry1Ab resistant and susceptible strains. …

Interactions Of Transgenic Bacillus Thuringiensis Insecticidal Crops With Spiders (Araneae), Julie A. Peterson, Jonathan Lundgren, James D. Harwood

Department of Entomology: Faculty Publications

Genetically modified crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) have dramatically increased in acreage since their introduction in the mid-1990’s. Although the insecticidal mechanisms of Bt target specific pests, concerns persist regarding direct and indirect effects on non-target organisms. In the field, spiders may be exposed to Bt toxins via multiple routes, including phytophagy and pollenivory, consumption of Bt-containing prey, and soil exudates in the detrital food web. Beyond direct toxicity, Bt crops may also have indirect impacts, including pleiotropic and preymediated effects. Here, we comprehensively review the literature and use meta-analyses to reveal that foliar spider abundance is …

Environmental Impact And Cost Benefit Analysis Of Biological Control Application, Jaime Molina-Ochoa, John E. Foster

Department of Entomology: Faculty Publications

The implications and interactions of the application of biological control agents in the environment, as well as the risks included by the introduction of exotic natural enemies are briefly reviewed. Description of the role of resistance or quality of the host plant to insect pests, and their interaction with biocontrol agents is provided. A need to increase applications or find new alternatives and environmental impact towards non target insects, and the real cost of its use against the benefits is discussed.

Male Field Crickets Infested By Parasitoid Flies Express Phenotypes That May Benefit The Parasitoids, Oliver M. Beckers, William E. Wagner

School of Biological Sciences: Faculty Publications

Parasites can cause changes in the phenotypes of their hosts that may benefit the parasite, the host, or both. To understand the evolutionary dynamics of host–parasite interactions it is necessary to first examine the effect of parasitic infestation on the host phenotype and whether the host or parasite benefits from these changes. The fly Ormia ochracea parasitizes the variable field cricket, Gryllus lineaticeps, and it uses male song to locate hosts for its lethal larvae. Adult flies preferentially orient to male songs with faster and longer chirps. We tested the effect of larval infestation on two types of host traits. …

A Study Of Horn Fly, Haematobia Irritans (L.) (Diptera: Muscidae), Target-Site Sensitivity, Susceptibility, And Resistance Management At Selected Sites In Louisiana, Cole David Younger

LSU Doctoral Dissertations

The purpose of the first study was to evaluate the effectiveness of the use of a mid-season avermectin pour-on to cattle for managing OP resistance in horn fly populations at the Rosepine Louisiana Agricultural Research Station. During an eight year study, ivermectin treatments were made three times (when the treatment threshold of less than five weeks of control was reached), and in the following years, the number of weeks of control increased to 9 to 10 weeks each time. The purpose of the second study was to test a two-year OP/one-year pyrethroid rotation strategy as a strategy for maintaining susceptibility …

Biological Control Of The Black Cutworm, Agrotis Ipsilon (Lepidoptera: Noctuidae), And Endophyte Mediated Tritrophic Interactions In Turfgrass, Andrea Jeanne Bixby-Brosi

University of Kentucky Doctoral Dissertations

Components of successful pest management programs must be complementary and not antagonistic. This project examined interactions between natural enemies of the black cutworm, Agrotis ipsilon (Hufnagel), an important turfgrass pest, and host plant resistance by endophytic grass.

Agrotis ipsilon nucleopolyhedrovirus (AgipMNPV) was examined as a bio-insecticide for controlling A. ipsilon in turfgrass. Fresh (1-week-old) AgipMNPV residues killed 76−86% of neonates hatching from eggs on golf course tees, however, residual control of implanted larvae lasted no more than a few weeks. Combinations of AgipMNPV with adjuvants, such as optical brightener and lignin, failed to accelerate or extend …

Ixodes Affinis (Acari: Ixodidae) In Southeastern Virginia And Implications For The Spread Of Borrelia Burgdorferi, The Agent Of Lyme Disease, Robyn M. Nadolny, Chelsea L. Wright, Wayne L. Hynes, Daniel E. Sonenshine, Holly Gaff

Biological Sciences Faculty Publications

Ixodes affinis Neumann is a hard-bodied (ixodid) tick known to be a competent vector for Borrelia burgdorferi, the agent of Lyme disease, and agents of other human diseases (Keirans et al. 1999). Ixodes affinis has been reported in Florida, Georgia, and South Carolina and throughout coastal North Carolina (Clark et al. 1998, Harrison et al. 2010). Harrison et al. (2010) indicated that I. affinis was established throughout the coastal plain of North Carolina up to the Virginia border and suggested that I. affinis might occur in Virginia.

Phylogeographic Structure Of Teretrius Nigrescens (Coleoptera: Histeridae) Predator Of The Invasive Post Harvest Pest Prostephanus Truncatus (Coleoptera: Bostrichidae)., B. A. Omondi, J. Van Den Berg, D. Masiga, F. Schulthess

All Peer-Reviewed Publications

The invasive larger grain borer Prostephanus truncatus (Horn) is the most important pest of farm-stored maize in Africa. It was introduced into the continent from Mesoamerica in the late 1970s and by 2008 had spread to at least 18 countries. Classical biological control using two populations of the predator Teretrius nigrescens Lewis achieved long-term and cost effective control in warm-humid areas, but not in cool and hot-dry zones. The present study investigated the phylogenetic relationships between geographical populations of the predator. Ten populations of T. nigrescens were studied using randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR), sequence analysis of …

Parasitism Of Lepidopterous Stem Borers In Cultivated And Natural Habitats, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Stéphane Dupas, Paul-André Calatayud

All Peer-Reviewed Publications

Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, …

Dissemination Of Entomopathogenic Fungi Using Busseola Fusca Male As Vector, Nguya K. Maniania, Elizabeth Ouna, Peter Ahuya, Brigitte Frérot, Anne Emmanuelle Félix, Bruno Le Ru, Paul André Calatayud

All Peer-Reviewed Publications

The stem borer, Busseola fusca (Fuller), is an important pest of maize Zea mays L. and sorghum Sorghum bicolor (L.) in eastern and southern Africa. To control this pest, biological control methods including the use of entomopathogenic fungi are being considered. The pathogenicity of one isolate of Metarhizium anisopliae (Metsch.) Sorok. and one isolate of Beauveria bassiana Bals. (Vuill.) were first tested on different developmental stages of B. fusca including eggs, neonate, 2nd and 3rd-instar larvae. Both fungal isolates were pathogenic to all the stages tested. However, differences in mortality were observed among larvae that hatched from treated egg masses. …

Sex Pheromone Composition And Reproductive Isolation In Two Busseola Species (Lepidoptera: Noctuidae) In Kenya, A. E. Félix, P. A. Calatayud, B. Le Ru, J. F. Silvain, B. Frérot

All Peer-Reviewed Publications

Closely related species provide an interesting and useful model to understand mate communication diversification. Pre-mating isolation is the result of selection processes and is achieved by utilization of different sex pheromones, but also by different ecological and life traits such as geographic distribution, host-plant specialization and allochrony of sexual behavior. Here, we report sex pheromone identifications and pre-mating isolation of two closely related species of stemborers: Busseola segeta and the yet undescribed Busseola nov. sp., developing on different host-plants and in different geographical locations in Kenya. GC-MS analyses showed that the two species produced the same pheromone components, but in …

Oviposition Preferences Of The African Wild Silkmoth, Gonometa Postica Walker (Lepidoptera: Lasiocampidae) On Different Substrates, Ken O. Fening, Esther N. Kioko, Jones M. Mueke, Suresh K. Raina

All Peer-Reviewed Publications

Gonometa postica Walker (Lepidoptera: Lasiocampidae) is currently being utilised for commercial wild silk production in Eastern Kenya. The oviposition preferences of female G. postica on four substrates in a net-sleeved cage was studied in the laboratory in the long and short rainy seasons in 2007 for two generations, i. e. early (late March to April) and late flights (late September to October) of the moth. The first generation moths laid the highest number of eggs on net sleeves followed by plastic pot, twigs and wooden plank, whereas the second generation moths preferred wooden plank and net sleeves over the plastic …

The Flight Activity Of Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) And Teretrius Nigrescens Lewis (Coleoptera: Histeridae) In Kenya, Bonaventure Aman Omondi, Nanqing Jiang, Johnnie Van Den Berg, Fritz Schulthess

All Peer-Reviewed Publications

The invasive storage pest, the larger grain borer (LGB) Prostephanus truncatus (Horn), was introduced into the maize-deficit, semi-arid areas of the eastern region in Kenya in the early 1980s. In spite of containment efforts and the introduction of the predator Teretrius nigrescens Lewis from Mexico, LGB has spread to the main maize production zone in western Kenya during the past five years. The present work presents results from a 28-month monitoring effort of LGB and its predator, using pheromone traps at five locations along an east-west transect across Kenya. LGB occurred in all regions with highest trap catches in the …

Repellent Activity Of Catmint, Nepeta Cataria, And Iridoid Nepetalactone Isomers Against Afro-Tropical Mosquitoes, Ixodid Ticks And Red Poultry Mites, Michael A. Birkett, Ahmed Hassanali, Solveig Hoglund, Jan Pettersson, John A. Pickett

All Peer-Reviewed Publications

The repellent activity of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), and the main iridoid compounds (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone, was assessed against (i) major Afro-tropical pathogen vector mosquitoes, i.e. The malaria mosquito, Anopheles gambiae s.s. and the Southern house mosquito, Culex quinquefasciatus, using a World Health Organisation (WHO)-approved topical application bioassay (ii) the brown ear tick, Rhipicephalus appendiculatus, using a climbing repellency assay, and (iii) the red poultry mite, Dermanyssus gallinae, using field trapping experiments. Gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS) analysis of two N. cataria chemotypes (A and B) used in the repellency assays …

Advanced Management Of The Mexican Rice Borer (Eoreuma Loftini) In Sugarcane, Blake Emerson Wilson

LSU Master's Theses

Insecticide, greenhouse and varietal resistance experiments were conducted in Texas to develop management tactics for the Mexican rice borer, Eoreuma loftini (Dyar), sugarcane. A 3-treatment, large plot aerial application study was set up in 5 commercial sugarcane fields (35-84 acres) to evaluate the utilization of pheromone traps to improve chemical control strategies for E. loftini during 2009 and 2010 growing seasons. A threshold of 20-25 moths/trap/wk was used as an indicator to initiate monitoring for E. loftini larval infestations. Larval infestations were directly related to the no. of moths/trap/wk (R2=0.71). Reductions in borer injury and adult emergence (60% and 40% …

Evaluation Of Species Distribution Model Algorithms For Fine-Scale Container-Breeding Mosquito Risk Prediction, C. Khatchikian, Florencia Sangermano, D. Kendell, T. Livdahl

Geography

The present work evaluates the use of species distribution model (SDM) algorithms to classify high densities of small container-breeding Aedes mosquitoes (Diptera: Culicidae) on a fine scale in the Bermuda Islands. Weekly ovitrap data collected by the Department of Health, Bermuda for the years 2006 and 2007 were used for the models. The models evaluated included the algorithms Bioclim, Domain, GARP (genetic algorithm for rule-set prediction), logistic regression and MaxEnt (maximum entropy). Models were evaluated according to performance and robustness. The area under the receiver operating characteristic curve was used to evaluate each model's performance, and robustness was assessed according …

Introduction And Establishment Of Cyrtobagous Salviniae Calder And Sands (Coleoptera: Curculionidae) For The Control Of Salvinia Minima Baker (Salviniaceae), And Interspecies Interactions Possibly Limiting Successful Control In Louisiana, Katherine A. Parys

LSU Doctoral Dissertations

Common salvinia, Salvinia minima Baker, is a floating aquatic invasive macrophyte that obstructs waterways and causes problems in wetlands across Louisiana and Texas. The salvinia weevil, Cyrtobagous salviniae Calder and Sands, has been released in over 14 countries around the world for the biological control of Salvinia spp. We successfully monitored the introduction and establishment of C. salviniae on S. minima in southern Louisiana between 2006 and 2010. Cyrtobagous salviniae significantly lowered the biomass of S. minima and increased the number of terminal buds damaged but had no significant impact on pH, dissolved oxygen, conductivity, surface temperature, percent of surface …

Contribution Of Bacillus Thuringiensis Cotton Cultivars And Insecticides To A Fall Armyworm, Spodoptera Frugiperda (J. E. Smith), (Lepidoptera : Noctuidae) Management Strategy, Jarrod T. Hardke

LSU Doctoral Dissertations

Fall armyworm, Spodoptera frugiperda (J. E. Smith), response to cottons, Gossypium hirsutum L., expressing Bacillus thuringiensis (Bt) insecticidal proteins, Cry1Ac (Bollgard®), Cry1Ac + Cry2Ab (Bollgard II®), and Cry1Ac + Cry1F (WideStrike™), was evaluated in field and laboratory experiments. In field trials, larvae that were infested on selected fruiting forms (squares, white flowers, and bolls) of WideStrike™ plants had lower survivorship and caused less injury than larvae on non-Bt plants, regardless of fruiting structures. Bollgard® and Bollgard II® plants produced no consistent negative effects on fall armyworm survivorship and injury. In no-choice laboratory assays, Bollgard II® and WideStrike™ cotton tissue reduced …

Role Of Substrate Moisture, Relative Humidity And Temperature On Survival And Foraging Behavior Of Formosan Subterranean Termites, Bal Krishna Gautam

LSU Doctoral Dissertations

The Formosan subterranean termite is an important structural pest in the southern United States, especially Louisiana. Baiting systems and spot treatment with non-repellent delayed action termiticides are among the most eco-friendly control approaches. However, to achieve a desired success from these approaches requires a sophisticated knowledge of foraging behavior and food transfer system of these social insects. Moisture and temperature play a vital role in influencing the foraging behavior of these desiccation prone insects. A series of laboratory experiments were conducted to understand the subtleties of foraging behavior of Coptotermes formosanus Shiraki in relation to moisture, relative humidity and temperature. …

Molecular Mechanisms Of Bacillus Thuringiensis Resistance In The Sugarcane Borer, Yunlong Yang

LSU Doctoral Dissertations

The sugarcane borer, Diatraea saccharalis, is a major target pest of transgenic corn expressing Bacillus thuringiensis (Bt) proteins in many areas of the U.S. mid-southern region. A Cry1Ab-resistant (Cry1Ab-RR) strain of D. saccharalis has been developed from a single two-parent family-line. To examine the molecular mechanisms of the Cry1Ab resistance in this insect strain, cDNAs of five types of potential candidate genes related to Bt resistance were sequenced using reverse transcriptase polymerase chain reaction (RT-PCR) and 5’ rapid amplification of cDNA end (5’ RACE). The Bt resistance candidate genes examined included three trypsins (DsTRYs), three chymotrypsins (DsCHYs), three aminopeptidases N …