Early-maturing and full-season Bt and non-Bt cottons were exposed to high densities of tobacco budworm (Heliothis virescens (F.)) and bollworm (Helicoverpa zea Boddie) in 0.04 ha field cages during the summers of 2011 and 2012 to measure the possible need for supplemental use of insecticides on Bt cotton. Fruit survival within-season and at-harvest was carefully mapped on individual plants within comparative plots of all cottons untreated and sprayed with lambda-cyhalothin (0.0448 kg a.i./ha) or chlorantraniliprole (0.1009 kg a.i./ha) following insect infestations. Differences in lint yields among cotton maturity groups were not always detected, but early-maturing Bt cottons were among the higher yielding experimental plots for both years. Depending on the insecticide treatment, average harvested fruit ranged from 0.3 to 7.1 open bolls per plant for non-Bt cotton plots, while Bt cotton plots ranged from 1.8 to 7.5 open bolls per plant during the two-year study. Bt cottons generally protected fruit from insect damage and resulted in final yields comparable to those of insecticide sprayed Bt and non-Bt cottons. Unsprayed non-Bt cottons were significantly damaged by insects in these high-infestation environments.

Nuclear polyhedrosis viruses have been labeled for use as microbial insecticides in agronomically-important crops in the U.S. since the 1970s. New products developed from viral isolates of different species in the heliothine genera Helicoverpa, Heliothis, and Chloridea have been introduced to the market and are receiving renewed attention for controlling heliothine pests. Two laboratory assays were used to evaluate comparative activities among the first nuclear polyhedrosis viruses registered in the U.S. and two commercially-available baculovirus products for controlling bollworm, Helicoverpa zea (Boddie), and tobacco budworm, Chloridea virescens (F.). Based on comparisons of LC50S of formulated products from laboratory overlay assays at 7 days, Gemstar was 2.4 and 3.7 fold less active than Elcar against bollworm and tobacco budworm, respectively. Heligen was 2.9 and 7.1 fold more active than Elcar against bollworm and tobacco budworm, respectively. However, once corrected for concentration of polyhedral occlusion bodies, susceptibility of bollworm did not differ to any of the three products tested. Tobacco budworms were more susceptible to Heligen than Gemstar in laboratory overlay assays following correction for differences in concentration of polyhedral occlusion bodies, which might be caused by interrelatedness of the species with the Old World bollworm. No discernable difference in death of bollworms or tobacco budworms was detected among the greatest labeled rate of any formulated microbial insecticide sprayed on leaves of non-Bt cotton (Gossypium hirsufum L.) at 14 days and percentage of pupation at 20 days post-treatment. Although the activity of wild-type baculovirus has changed little during the past four decades, use of the products should be encouraged whenever possible. Potential ecological benefits of preserving beneficial insects and reducing selection for resistance to insecticides should be promoted as long as effectiveness and costs are reasonable.

Two isolates of Beauveria bassiana (Balsamo) Vuillemin, including the commercial strain GHA and the Mississippi Delta native NI8 strain, and two emulsifiers, Tween-80 and a starch-based sprayable bioplastic, were evaluated in the laboratory and field for pathogenicity and infectivity against the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae). The effect on fruit damage based on within-season cotton plant mapping was also examined. The highest mortality 10 d after treatment was found with insects caged on cotton terminals sprayed with NI8 + Tween-80, followed by those exposed to NI8 + bioplastic. Similarly, sporulation was shown to be higher in NI8 + Tween-80 than in other treatments. Plots sprayed with B. bassiana showed at least a twofold decrease in tarnished plant bug adults 3 d after treatment compared with control plots. Little to no variation was observed in tarnished plant bug nymph populations between treated and untreated plots. Within-season plant mapping provided clear evidence of damage to cotton caused by tarnished plant bug. The highest percentage retention of all first position fruiting structures was observed in plots treated with NI8 + Tween-80 (93.41 ± 1.51) followed by NI8 + bioplastic (90.25 ± 1.52). Both treatments were significantly different when compared with GHA + Tween-80 (82.89 ± 2.26) and GHA + bioplastic (70.48 ± 3.19), and both GHA formulations did not differ from the control (63.61 ± 2.96). Overall, these results indicated that B. bassiana application resulted in >50% mortality of tarnished plant bug regardless of the isolates by direct spray or by contact. However, the superior performance of the Mississippi Delta native NI8 strain was observed in all treatment applications and evaluation times.

The use of neonicotinoid insecticides in the United States has grown by about a factor of four since the mid-2000s. Seed treatments account for a significant fraction of overall insecticide application to crops, and a large proportion of major U.S. crops are now planted using seed treated with neonicotinoids. Neonicotinoid insecticidal seed treatments are primarily intended to protect crops against sporadic or minor early-season pests. A better understanding of factors that influence the risk of economic infestations and extent of crop damage by sporadic pests is needed to target neonicotinoid insecticidal seed treatments use based on expected pest pressure. In a series of papers, we review the distribution, ecology, and historical management of seed and seedling pests targeted by neonicotinoid seed treatments in U.S. corn (Zea mays), soybean (Glycine max), wheat (Triticum aestivum), and cotton (Gossypium hirsutum L.). This information is key to region-specific management practices that reduce the risks and increase the benefits of neonicotinoid seed treatments.

Soybean faces potential economic damage from a wide variety of early-season invertebrate pests. The objective of this article was to determine the extent and intensity of nine early-season soybean insect pests targeted for control by insecticidal seed treatments in the United States and to identify various management options for them: bean leaf beetle (Cerotoma trifurcate Forster, Coleoptera: Chrysomelidae); grape colaspis, Colaspis brunnea (F.) (Coleoptera: Chrysomelidae); leafhoppers (Hemiptera: Ciccadellidae); seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae); soybean aphid (Aphis glycines Matsumura, Hemiptera: Aphididae); threecornered alfalfa hopper, Spsistilus festinus (Say) (Hemiptera: Membracidae); thrips (Thysanoptera: Thripidae); white grubs (Coleoptera: Scarabaeidae); and wireworms (Coleoptera: Elateridae). Seedcorn maggot, white grubs, and wireworms have been limited to a relatively small proportion of soybean fields with readily defined factors regarding their risk. However, questions about the pest status of the other six pests were identified. Bean leaf beetle, which vectors Bean pod mottle virus to soybean, has been present across major soybean-production regions, but frequency and proportion of soybean fields that economically impacted is not adequately documented. The impact of threecornered alfalfa hopper and thrips on soybean productivity varied within regions, but specific reasons for the variation were unclear. Early-season management of grape colaspis and leafhoppers has been infrequent, but factors that promoted economic injury and the need for management in specific fields were undetermined. Although early-season management of soybean aphid has not proven feasible for individual fields, questions remain regarding its management in fields near overwintering stands and the possibility for areawide suppression.

Populations of tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), from the Lower Mississippi Delta regions of Arkansas, Louisiana, and Mississippi were evaluated from 2008 through 2015 for susceptibility to pyrethroid insecticides using a diagnostic-dose assay with permethrin. Resulting data add to the compilation of pyrethroid susceptibility data carefully tracked in this pest since 1994 and provide continuing evidence of high frequencies of pyrethroid resistance in field populations of the tarnished plant bug. Resistance levels are variable, and some populations remain susceptible suggesting practical value in the continued use of the diagnostic-dose assays prior to pyrethroid treatments. Recent studies with dose-response models suggest that levels of pyrethroid resistance in some populations may still be evolving, with some populations requiring higher doses to reach levels of control comparable to those observed 10 yr ago. Concerns for frequent use of multiple classes of insecticides and possible selection for tarnished plant bugs with metabolic resistance mechanisms capable of detoxifying available insecticide chemistries warrant continued efforts to manage resistance in this important crop pest. Associations among measured pyrethroid resistance levels, published data on annual use of pyrethroid insecticides, and annual estimates of cotton insect losses and control costs were explored and summarized for the 8 yr of this investigation. Mortality of tarnished plant bugs at the diagnostic-dose of permethrin was negatively correlated with kilograms of pyrethroids applied per acre of harvested cropland.

The Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae); cereal aphids (Hemiptera: Aphididae); and wireworms (Coleoptera: Elateridae) are three common and important insect pests of seedling wheat, Triticum aestivum L., in the United States. Though less common as pests, false wireworms (Coleoptera: Tenebrionidae) may also be problematic in situations that favor wireworms. In addition, cereal aphids vector viruses that cause barley yellow dwarf, a serious and widespread wheat disease. Scientific journal publications, review articles, and management guidebooks on wheat insect pests were consulted to determine the extent and intensity that these pests impose on wheat production in the United States. Widespread outbreaks occur infrequently, but local outbreaks happen nearly every year for the three major pests and cause several millions of dollars in crop losses annually. Hessian fly perennially threatens wheat in the southeastern United States, and wireworms are persistent pests in northwestern wheat-production systems. Otherwise, the particular location and severity of outbreaks vary yearly and are largely unpredictable. However, particular agronomic practices can greatly reduce risk of infestation such as elimination of volunteer wheat and weedy hosts and planting wheat during periods of reduced pest abundance. In addition, resistant cultivars can limit Hessian fly and Russian wheat aphid (Diuraphis noxia [Kurdjumov]) damage in some areas, but virulent biotypes of each pest complicate their management. Although several preemptive tactics reliably suppress infestations and barley yellow dwarf severity, they are not compatible in all agricultural systems. Consequently, insecticides are necessary in certain areas and within particular production systems to manage major early-season insect pests of wheat.

The use of insecticides at planting has been a common crop management practice in cotton for several decades. Historically, U.S. cotton growers relied on in-furrow applications of insecticides, such as aldicarb, to control early-season insect pests. In-furrow applications have largely been replaced with insecticide-treated seed. Since 2012, more than 60% of the U.S. cotton crop is planted with seed treated with insecticide, primarily the neonicotinoids imidacloprid or thiamethoxam. Several insects or insect groups are included on the labels of these neonicotinoids for use as seed treatments. An increased understanding of the risks associated with economically injurious populations of insect pests is needed to optimize use of early-season insecticides and reduce over-reliance on them in cotton, especially when initial decisions for insect control before planting have subsequent influence on future pest abundance. Existing literature pertaining to these early-season cotton insect pests was examined to identify factors favoring their distribution and abundance and the importance of insect control tactics used at planting. The relative importance of some of these pests is dependent on the cotton-growing region and impacted by local production practices. Thrips (predominantly Frankliniella spp.) (Thysanoptera: Thripidae) are the most prevalent early-season insect group in cotton across the United States and the primary target of initial insect control. Other targeted insects include the black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), aphids (predominantly Aphis gossypii Glover) (Hemiptera: Aphididae), plant bugs (Hemiptera: Miridae), and wireworms (Coleoptera: Elateridae).

A laboratory colony of tarnished plant bugs reared solely on a meridic diet was exposed to acephate, imidacloprid, permethrin, sulfoxaflor, and thiamethoxam in dose-response experiments using floral-foam, glass-vial, and dipped-leaf assays. Results indicated that different assay methods produced different relative results across the different insecticides. Dose- and time-response regression models also indicated that length of exposure of tarnished plant bugs to insecticide-treated plant tissue is important. Time of exposure required to reach an LC90 at estimated recommended field rates suggested that the recommended lower field rate of acephate (0.56 kg ai/ha) would reach an LC90 of exposed tarnished plant bugs between 48 and 96 h post initial exposure. An LC90 of tarnished plant bugs exposed to permethrin (0.11 kg ai/ha) was not predicted from the regression modes over the 168-h observation; lower recommended application rates of imidacloprid (0.053 kg ai/ha), sulfoxaflor (0.053 kg ai/ha), and thiamethoxam (0.042 kg ai/ha) reached projected LC90s between 96 and 168 h of exposure. Collectively, the results of this study corroborate current existing procedures for tracking tarnished plant bug resistance to insecticides, but also illustrate the importance of additional field studies that empirically associate assay results to projected field control.

Acephate (organophosphate) is frequently used to control piercing/sucking insects in field crops in southern United States, which may pose a risk to honey bees. In this study, toxicity of acephate (formulation Bracket®97) was examined in honey bees through feeding treatments with sublethal (pollen residue level: 0.168 mg/L) and median-lethal (LC50: 6.97 mg/L) concentrations. Results indicated that adult bees treated with acephate at residue concentration did not show significant increase in mortality, but esterase activity was significantly suppressed. Similarly, bees treated with binary mixtures of acephate with six formulated pesticides (all at residue dose) consistently showed lower esterase activity and body weight. Clothianidin, λ-cyhalothrin, oxamyl, tetraconazole, and chlorpyrifos may interact with acephate significantly to reduce body weight in treated bees. The dose response data (LC50: 6.97 mg/L) revealed a relatively higher tolerance to acephate in Stoneville bee population (USA) than populations elsewhere, although in general the population is still very sensitive to the organophosphate. In addition to killing 50% of the treated bees acephate (6.97 mg/L) inhibited 79.9%, 20.4%, and 29.4% of esterase, Glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities, respectively, in survivors after feeding treatment for 48 h. However, P450 activity was elevated 20% in bees exposed to acephate for 48 h. Even though feeding on sublethal acephate did not kill honey bees directly, chronic toxicity to honey bee was noticeable in body weight loss and esterase suppression, and its potential risk of synergistic interactions with other formulated pesticides should not be ignored.

Supplemental control with diamides for bollworm, Helicoverpa zea (Boddie), in Bt cotton is becoming more frequent, but there is little information on net returns to growers. The value of spraying Bt cotton with commercially available diamides was evaluated at seven locations in the Mississippi Delta cropping region in 2014 and 2015. Plots of Bollgard II (R), Widestrike 3((R)), and non-Bt cotton varieties planted at each location were divided into five subplots. Treatments randomly assigned to subplots of each cotton cultivar were: 1) lowest labeled rate of chlorantraniliprole applied at threshold, 2) lowest labeled rate of flubendiamide applied at threshold, 3) lowest labeled rate of lambda- cyhalothrin + chlorantraniliprole applied at threshold, 4) sprayed check, which was the maximum labeled rate of chlorantraniliprole applied on a 3- week schedule and initiated before first bloom to minimize damage from heliothines, and 5) nontreated check. Each plot was monitored weekly for larval abundance and plant damage by examining 100 plants at random. Supplemental control applications were initiated when larval abundance (>= 4 per 100 plants) and plant damage (> 2% damaged bolls with larvae present) met economic thresholds outlined by the Mississippi State University Extension Service. Following first bloom, all non-target pests were controlled with broadcast sprays of insecticide with low or no known toxicity to heliothines. No differences were detected in yield among treatments for any given Bt cotton variety. In non-Bt cotton, all threshold treatments and the sprayed check yielded significantly more lint cotton per hectare than did nontreated plots. Mean larval numbers per 100 plants ranged from 0.75-5.95 in non-Bt cotton to 0.04-0.8 and 0.44-1.17 in Bollgard II and Widestrike 3 cottons, respectively. Non-Bt cotton required approximately one additional diamide application for heliothine control as compared to Bt cotton plots. Results indicated no economic benefit to supplemental spray of diamides for bollworms in Bt cotton at larval abundance observed during the study. Bt cotton alone seemed sufficient to control bollworms. This should provide confidence for producers to avoid overspray at near threshold densities of bollworms.

Here, we report on the first state and county record of Euschistus quadrator Rolston (Hemiptera: Pentatomidae) in Washington County, Mississippi. The species has been documented from Honduras to Virginia primarily on soybean, cotton, various row crops, fruit, and non-crop hosts. The local impact on agricultural crops in the area is unknown. The lack of E. quadrator sightings in Mississippi compared with the frequency of occurrence in literature from Louisiana is of interest. Weather patterns may have contributed to the range expansion. Future efforts to educate growers and consultants on identifying key characteristics of the various Euschistus species common in the southeastern United States may reveal an even larger distribution of E. quadrator in the state and region.

Bioassays were conducted to examine the pathogenicity of the fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales), strain NI8, against Lygus lineolaris (Palisot de Beauvois) and its impact on beneficial arthropods including Apis mellifera L., Crysoperla rufrilabris Burmeister, Orius insidiosus Say, Hippodamia convergens Guerin-Meneville, Harmonia axyridis (Pallas), Coleomegilla maculata De Geer, and field-collected Aranea spiders Salticidae and Thomisidae. Insects were treated with four concentrations of NI8 (3.9 x 10(4), 2.3 x 10(5), 4.2 x 10(6), and 1.5 x 10(7) spores/ml) directly via topical spray. Median lethal concentration (LC50), sporulation response, and resistance ratio were estimated for all species except for the two groups of spiders. No significant differences in mortality (10 d after application) were observed among L. lineolaris, A. mellifera, and C. rufilabris, and all three species were highly affected when exposed to the highest concentrations of B. bassiana with 99.0, 98.2, and 90.0% mortality, respectively. Between 35 and 45% of the tested populations of O. insidiosus, H. convergens, field-collected crab spiders, and C. maculata were killed at 1.5 x 10 7 spores/ml; whereas only 22 and 27%, respectively, of the field-collected jumping spiders and H. axyridis were killed at 10 d with the same concentration. No significant differences were found between the LC(50)s measured for L. lineolaris and C. rufilabris 10 d after application. Results suggested that C. rufilabris would be highly affected by the NI8 strain of B. bassiana when applied for control of L. lineolaris. In contrast, B. bassiana appeared to have lower effects on the other beneficial arthropods assayed at the concentrations targeted for L. lineolaris control.

A Mississippi Delta native strain (NI8 ARSEF8889) of Beauveria bassiana (Bals.-Criv.) Vuill. (Cordycipitaceae), isolated from Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), was tested on green lacewings, Chrysoperla rufilabris (Burmeister) (Neuroptera: Chrysopidae) at 4 spray concentrations (7.02 x 104, 105, 106, and 107 spores per mL) to evaluate effects on reproductive rates and adult life expectancy of this insect predator. The application method simulated atomized spray, and concentrations tested were similar to those used to measure impacts of the fungus on L. lineolaris. Significant effects of B. bassiana on C. rufilabris adults were found, and the severity of impact depended on the concentrations tested. Beauveria bassiana impacted all demographic measurements of C. rufilabris reproduction and survival. Intrinsic and finite rates of increase and gross and net reproductive rates of adults treated with the highest concentrations tested were significantly decreased, whereas doubling time increased for adults treated with the lowest test concentrations. Based on these observations, C. rufilabris will be affected by sprays of B. bassiana targeted at L. lineolaris if adults are present at the time and location of treatment. The measured lethal concentration, LC50, of 2.11 viable spores per mm(2) compares to an LC50 of 2.75 spores per mm(2) determined previously for L. lineolaris. Higher concentrations of spores per mm(2) were required for sporulation (SR50) of the entomopathogenic fungus on C. rufilabris (13.60 viable spores per mm(2)) than concentrations required for mortality (LC50).

Imidacloprid is the most widely used insecticide in the world. In this study, we used spraying methods to simulate field exposures of bees to formulated imidacloprid (Advise® 2FL) alone and binary mixtures with seven pesticides from different classes. Synergistic toxicity was detected from mixtures of Advise (58.6 mg a.i./L imidacloprid)+Domark (512.5 mg a.i. /L tetraconazole), Advise+Transform (58.5 mg a.i./L sulfoxaflor), and Advise+Vydate (68 mg a.i./L oxamyl), and mortality was significantly increased by 20%, 15%, and 26% respectively. The mixtures of Advise+Bracket (88.3 mg a.i./L acephate) and Advise+Karate (62.2 mg a.i./L L-cyhalothrin) showed additive interaction, while Advise+Belay (9.4 mg a.i./L clothianidin) and Advise+Roundup (1217.5 mg a.i./L glyphosate) had no additive/synergistic interaction. Spraying bees with the mixture of all eight pesticides increased mortality to 100%, significantly higher than all other treatments. Except Bracket which significantly suppressed esterase and acetylcholinesterase (AChE) activities, other treatments of Advise-only and mixtures with other pesticides did not suppress enzyme activities significantly, including invertase, glutathione S-transferase (GST), and esterase and AChE. Immunity-related phenoloxidase (PO) activities in survivors tended to be more variable among treatments, but mostly still statistically similar to the control. By using specific enzyme inhibitors, we demonstrated that honey bees mainly rely on cytochrome P450 monooxygenases (P450s) for detoxifying Advise, while esterases and GSTs play substantially less roles in the detoxification. This study provided valuable information for guiding pesticide selection in premixing and tank mixing in order to alleviate toxicity risk to honey bees. Our findings indicated mixtures of Advise with detoxification-enzyme-inducing pesticides may help bees to detoxify Advise, while toxicity synergists may pose further risk to bees, such as the Bracket which not only suppressed esterase and AChE activities, but also increased toxicity to bees.

Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen) induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate), Karate (λ-cyhalothrin), Vydate (oxamyl), Domark (tetraconazole), and Roundup (glyphosate) at residue level had a mortality range of 1.3-13.3%, statistically similar to that of control (P>0.05). The additive/synergistic toxicity was not detected from binary mixtures of Advise with different classes of pesticides at residue levels. The feeding of the mixture of all seven pesticides increased mortality to 53%, significantly higher than Advise only but still without synergism. Enzymatic data showed that activities of invertase, glutathione S-transferase, and acetylcholinesterase activities in imidacloprid-treated survivors were mostly similar to those found in control. Esterase activity mostly increased, but was significantly suppressed by Bracket (acephate). The immunity-related phenoloxidase activity in imidacloprid-treated survivors tended to be lower, but most treatments were statistically similar to the control. Increase of cytochrome P450 activity was correlated with Advise concentrations and reached significant difference at 56 mg/L (12 ppm a.i.). Our data demonstrated that residue levels of seven pesticide in pollens/hive may not adversely affect honey bees, but long term exclusive ingestion of the maximal residue levels of imidacloprid (912 ppb) and sulfoxaflor (3 ppm a.i.) may induce substantial bee mortality. Rotating with other insecticides is a necessary and practical way to reduce the residue level of any given pesticide.

Concentration-response assays were conducted from 2008 through 2015 to measure the susceptibility of field populations of Lygus lineolaris (Palisot de Beauvois) from the Delta regions of Arkansas, Louisiana, and Mississippi to acephate, imidacloprid, thiamethoxam, permethrin, and sulfoxaflor. A total of 229 field populations were examined for susceptibility to acephate, 145 for susceptibility to imidacloprid, and 208 for susceptibility to thiamethoxam. Permethrin assays were conducted in 2014 and 2015 to measure levels of pyrethroid resistance in 44 field populations, and sulfoxaflor assays were conducted against 24 field populations in 2015. Resistance to acephate and permethrin is as high or higher than that previously reported, although some populations, especially those exposed to permethrin, appear to be susceptible. Variable assay responses were measured for populations exposed to imidacloprid and thiamethoxam. Average response metrics suggest that populations are generally susceptible to the neonicotinoids, but a few populations from cotton fields experiencing control problems exhibited elevated LC50s. Efforts to associate variability in LC50s with recorded use of insecticides and estimated cotton insect losses and control costs suggest that intensive use of insecticides over several decades may have elevated general detoxifying enzymes in L. lineolaris and some field populations may be exhibiting resistance to multiple classes of insecticide. These results suggest that efforts should be made to manage these pests more efficiently with a reduced use of insecticides and alternative controls.

The mitochondrial genome (mitogenome) of the bollworm, Helicoverpa zea (Boddie), was assembled using paired-end nucleotide sequence reads generated with a next-generation sequencing platform. Assembly resulted in a mitogenome of 15,348 bp with greater than 17,000-fold average coverage. Organization of the H. zea mitogenome (gene order and orientation) was identical to other known lepidopteran mitogenome sequences. Compared with Helicoverpa armigera (Hübner) mitogenome, there were a few differences in the lengths of gaps between genes, but the lengths of nucleotide overlaps were essentially conserved between the two species. Nucleotide composition of the H. zea mitochondrial genome was very similar to those of the related species H. armigera and Helicoverpa punctigera Wallengren. Mapping of RNA-Seq reads obtained from 2-h eggs and 48-h embryos to protein coding genes (PCG) revealed that all H. zea PCGs were processed as single mature gene transcripts except for the bicistronic atp8 + atp6 transcript. A tRNA-like sequence predicted to form a hammer-head-like secondary structure that may play a role in transcription start and mitogenome replication was identified within the control region of the H. zea mitogenome. Similar structures were also found within the control regions of several other lepidopteran species. Expression analysis revealed significant differences in levels of expression of PCGs within each developmental stage, but the pattern of variation was similar in both developmental stages analyzed in this study. Mapping of RNA-Seq reads to PCG transcripts also identified transcription termination and polyadenylation sites that differed from the sites described in other lepidopteran species.

The kudzu bug, Megacopta cribraria (F.), is an urban nuisance and significant agricultural pest. The median lethal concentrations of three strains of Beauveria bassiana (Balsamo), including the Mississippi Delta native strain (NI8) isolated from Lygus lineolaris (Palisot de Beauvois), the commercial strain BotaniGard® (GHA) (Victor, NY, USA), and the B. bassiana strain isolated from M. cribraria (KUDSC), were estimated on kudzu bug adults. A technique developed to evaluate B. bassiana against L. lineolaris was used. Younger adults (eight days after collection) were treated with NI8 and GHA and older adult (50 days after collection) were treated with NI8, GHA and KUDSC. Higher concentrations (n × 106, n × 107) of NI8 and GHA caused kudzu bug mortality two days after treatment in younger adults and similar concentrations of NI8, GHA, and KUDSC caused mortality one day after treatment in older adults. Lower concentrations (n × 104, n × 105) were not significantly different in mortality between strains. LS50 values of the KUDSC were significantly lower than NI8 and GHA values in older adults. This is the first available information on median lethal concentration of B. bassiana on kudzu bug adults bioassayed on artificial diet. It was determined that B. bassiana (KUDSC and NI8) are highly effective for young adults at very low doses (LC50 1.98–4.98 viable spores per mm2).

Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations were collected from field locations in the Mississippi River Delta of Arkansas, Louisiana, and Mississippi. Third-instar F-1 nymphs from each field location, in addition to a laboratory colony, were screened for susceptibility to novaluron. Both a glass vial bioassay and a diet-incorporated bioassay used dose-response regression lines to calculate LC50 and LC90 values for novaluron. Mean LC50s for glass vial bioassays ranged from 44.706 +/- 3.58 to 66.54 +/- 64.19 mu g/vial, while mean LC50s for diet-incorporated bioassays ranged from 12.10 +/- 60.77 to 17.636 +/- 2.42 mu g/200 ml of artificial diet. A comparison of L-C50 values from the same field population screened using both bioassay methods failed to show a relationship. LC50 values from field locations were compared with a historically susceptible population from Crossett, AR. Results indicated that considerable variability in susceptibility to novaluron exists within field populations of tarnished plant bugs across the Delta, including some locations with lower LC50 values than a historically susceptible population.