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While transgenic plants targeting lepidopteran and coleopteran insects have been available for almost 20 yr, there are no transgenic crops that target hemipteran insects such as tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), though at least one company lists potential products in advanced stages of development. A resistance management model for the U.S. Mid-South was developed to aid in resistance risk assessments for transgenic crops targeting L. lineolaris , and validated against the prior case of pyrethroid resistance in this insect. The model predicted that resistance to a pyrethroid would evolve in 17.6–21.0 yr (depending on the initial resistance allele frequency), which was close to the 15–20 years observed in the field. Due to uncertainty in female fecundity, we varied fecundity from 3 eggs/female/day to 12 eggs/female/day. Sprays were applied based on action thresholds, and increasing fecundity therefore increased the number of sprays applied per year and decreased durability. We also varied the action threshold in cotton ( Gossypium hirsutum L.) fields (the population levels at which sprays were applied) from 17,600/ha to as low as 1,100/ha. Lowering the threshold increased the number of sprays applied, but also increased durability of the pesticide. Removing the noncotton host refuge present at the same time as cotton changed the relationship so that increasing the action threshold increased durability. The impact of insect resistance management on action threshold cost estimates will vary depending on the landscape, and cannot be assumed to always move the economic injury level in the same direction.

Lygus lineolaris (Palisot de Beauvois) and Lygus hesperus Knight are among the most important pests affecting production of cotton in the United States. Lygus spp. use a cell rupture feeding strategy. However, the precise stylet-probing behaviors of adult Lygus spp. are not well understood or quantifiably related to cotton damage. The long-term goals of our research are to: 1) relate stylet probing to damage, and 2) quantitatively compare L. lineolaris feeding among resistant and susceptible host plants. The specific objectives of this study were to apply the latest technology in electropenetrography (EPG) to record adult, prereproductive Lygus spp. feeding, to identify and characterize all the waveforms, and to hypothesize their biological meanings. We used a third-generation AC–DC electropenetrograph to record nonprobing and probing waveforms of adult bugs on pinhead (

While growing strawberries under plastic low tunnels is an increasing trend in the northeastern U.S., the effect of low tunnels on the incidence and severity of arthropod pests, pathogens, and weeds is largely unknown and presents a possible barrier to commercial adoption. During 2018 and 2019, we identified and quantified pest abundance on low tunnel versus open field grown strawberries at a research site in Geneva, New York, and compared these trends under three plastic types in 2019. Overall, we found that while yield and fruit marketability increased under tunnels of all plastic types compared to the open-field, ground-dwelling and foliar herbivores (mostly Tetranychus urticae) abundance was higher under low tunnels compared to open plots. In contrast, herbivores caught on clear sticky cards were more prevalent in open plots than under tunnels. A neutral effect of tunnels was present for Lygus lineolaris density and weed biomass during both years, although damage by L. lineolaris decreased under UV-limiting plastics. Tunnels also reduced infestation by Drosophila suzukii and several pathogens on foliage and fruit. This study provides needed information on pest communities of low tunnel strawberry in the Northeast, and could be used as an essential foundation for future IPM research.

To meet growing global food demand, producers are actively searching for ways tocrop yield. One way to boost yield is to reduce arthropod damage. However, insecticides are becoming less effective and can have detrimental effects on human health and the environment. Learning how to harness natural pest control is one way to reduce arthropod damage to crops and avoid adverse effects of insecticide use. Therefore, we examined the diets of two bat species that are likely to provide pest control services across the United States corn belt: the eastern red bat (Lasiurus borealis) and the big brown bat (Eptesicus fuscus). We also show that primer choice can impact the diversity of taxa detected and resecent adavances in primer design can improve diet detection studies. Using new ANML primers to isolate prey DNA in fecal material, we found a more diverse diet than previously reported for both bat species. Big brown bats consumed an average of 16.2 species from 8.5 genera. Red bats consumed an average of 28.6 species from 15.8 genera. We found pest genera in 92 % of big brown bat samples and 94 % of red bat samples. For both bat species, approximately two pest genera were detected in each sample. Corn rootworms (Diabrotica), Cloverworms (Hypena), plant bugs (Lygus), wireworms (Melanotus), seed corn beetles (Stenolophus), and armyworms (Spodoptera) were the most frequently consumed agricultural pests. We confirm earlier studies that document beetles (Coleoptera) and moths (Lepidoptera) as the most common prey items of big brown and red bats, respectively. However, we also document a diverse diet for both bat species that includes many true bugs (Hemiptera). Because pest control services of big brown and red bats are not completely overlapped, we conclude that a diverse bat community is essential to maximize pest control services by bats.

Lygus lineolaris populations have become increasingly problematic in Virginia cotton since 2013. Although production practices have changed, changes in landscape composition and climatic conditions are also anecdotally associated with increasing populations. To better understand the recent increase in L. lineolaris infestations in Virginia cotton, 56 commercial cotton fields were sampled weekly in 2017 and 2018 for a nine-week period during the growing season. Insect density was measured using sweep net and black drop cloth sampling, targeting adult and nymphal populations, respectively. Geospatial crop production and forest disturbance data were used to measure the composition and management history of landscapes adjacent to sample fields. We also used spatial climate data sets to document the relationship between increasing L. lineolaris and temperature variation. We investigated the significance of landscape composition and climatic effects increasing L. lineolaris infestation intensity using a regression modeling approach. We found the best overall predictor of L. lineolaris abundance was higher annual minimum temperatures. Several crop components in the landscape were significant, specifically corn and double-crop winter wheat and soybeans, but these habitat patches did not explain high levels of variability. Results of this study suggest that increasing minimum temperatures will favor L. lineolaris and may translate into elevated infestation intensity and increasing dependence on insecticide inputs to manage this problematic pest of cotton. Results of this study will be important to describe short- and long-term factors driving L. lineolaris infestation risk in cotton agroecosystems.

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.

Lygus species of plant-feeding insects have emerged as economically important pests of cotton in the United States. These species are not controlled by commercial Bacillus thuringiensis (Bt) cotton varieties resulting in economic losses and increased application of insecticide. Previously, a Bt crystal protein (Cry51Aa2) was reported with insecticidal activity against Lygus spp. However, transgenic cotton plants expressing this protein did not exhibit effective protection from Lygus feeding damage. Here we employ various optimization strategies, informed in part by protein crystallography and modelling, to identify limited amino-acid substitutions in Cry51Aa2 that increase insecticidal activity towards Lygus spp. by200-fold. Transgenic cotton expressing the variant protein, Cry51Aa2.834_16, reduce populations of Lygus spp. up to 30-fold in whole-plant caged field trials. One transgenic event, designated MON88702, has been selected for further development of cotton varieties that could potentially reduce or eliminate insecticide application for control of Lygus and the associated environmental impacts.

The mirine plant bug genus Prolygus Carvalho, 1987 (Hemiptera: Heteroptera: Miridae: Mirinae: Mirini) and superficially reminiscent taxa in eastern Asia (mainly in Japan, P. R. China and Taiwan) are reviewed. Four species in the region are now assigned to Prolygus. Three new genera, Anthophilolygus gen. nov., Miyamotolygus gen. nov. and Poppiolygus gen. nov., are proposed to accommodate Prolygus bakeri (Poppius, 1915), Neolygus rufilorum (Lu & Zheng, 2004) and Lygus bengalicus Reuter, 1885, respectively. Ten new combinations and three new synonymies are established: Apolygopsis eoa (Poppius, 1915) comb. nov. [transferred from Apolygus China, 1941]; A. fuhoshoensis (Poppius, 1915) comb. nov. [Apolygus]; A. nigra (Poppius, 1915) comb. nov. [Prolygus]; Anthophilolygus bakeri (Poppius, 1915) comb. nov. [Prolygus] = P. tainanensis (Poppius, 1915) syn. nov.; Micromimetus rubrotinctus (Carvalho, 1956) comb. nov. [Lygus sensu lato]; Miyamotolygus bui (Lu & Zheng, 2004) comb. nov. [Neolygus Knight, 1917]; M. pictus (Lu & Zheng, 2004) comb. nov. [Neolygus]; M. rufilorum (Lu & Zheng, 2004) comb. nov. [Neolygus]; Poppiolygus bengalicus (Reuter, 1885) comb. nov. [Lygus sensu lato] = Prolygus kirkaldyi (Poppius, 1915) syn. nov.; Prolygus disciger (Poppius, 1915) comb. nov. [Neolygus]; P. palauensis (Carvalho, 1956) comb. nov. [Lygus sensu lato]; P. nigriclavus (Poppius, 1915) = Neolygus nigroscutellaris (Lu & Zheng, 2004) syn. nov. Two additional new species, Anthophilolygus alaneylesi sp. nov. (central Thailand) and Micromimetus sunweni sp. nov. (Lanyu Island, Taiwan), are also described. The lectotype is designated for Lygus bengalicus Reuter. Lygus sacchari Matsumura, 1910 is regarded as nomen dubium.

Lygus sacchari Matsumura, 1910 Lygus sacchari Matsumura 1910: 23 (original description). Lygus sacchari: YASUNAGA et al. (1996): 92 (note on missing type specimen); SCHUH (2013) (online catalog). Comments. This is the final unclear member of the Lygus -complex in eastern Asia. Although the type material appears to have been lost (cf. YASUNAGA et al. 1996), this taxon, described from Taiwan, most probably belongs to Deraeocoris Kirschbaum, 1856 (Deraeocorinae) or its allied genera (e.g., Dortus Distant, 1910), or to Prodromus Distant, 1904 (Bryocorinae), judging from the original description (MATSUMURA 1910). SHIRAKI (1913) subsequently provided a detailed redescription in Japanese and also mentioned rice, sugar cane, and various weeds as hosts. Lygus sacchari is currently presumed to fit Dortus chinai Miyamoto, 1965, a common graminoid inhabitant in Taiwan and southwestern Japan (YASUNAGA 2001). This taxon nonetheless should be treated as nomen dubium, due to absence of the type series., Published as part of Yasunaga, Tomohide, Schwartz, Michael D. & Chérot, Frédéric, 2018, Review of the plant bug genus Prolygus and related mirine taxa from eastern Asia (Hemiptera: Heteroptera: Miridae), pp. 357-388 in Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) (Acta. Ent. Mus. Natl. Pragae) 58 (2) on page 385, DOI: 10.2478/aemnp-2018-0030, http://zenodo.org/record/4504807, {"references":["MATSUMURA S. 1910: Die schadlichen und nutzlichen Insekten vom Zuckerrohr Formosas. Keiseisha, Tokyo, 52 pp.","YASUNAGA T., MIYAMOTO S. & KERZHNER I. M. 1996: Type specimens and identity of the mirid species described by Japanese authors in 1906 - 1917 (Heteroptera: Miridae). Zoosystematica Rossica 5: 91 - 94.","SCHUH R. T. 2013: On-line Systematic Catalog of Plant Bugs (Insecta: Heteroptera: Miridae). http: // research. amnh. org / pbi / catalog / (Last accessed: July 27, 2018.)","SHIRAKI T. 1913: Investigations upon general insect pests. Special Report of the Formosa Agricultural Experiment Station 8: 186 - 187 (in Japanese).","YASUNAGA T. 2001: Family Miridae Hahn, plant bugs. In: YASUNAGA T., TAKAI M. & KAWASAWA T. (eds.): A Field Guide to Japanese Bugs II. Zenkoku Noson Kyoiku Kyokai Publ. Co. Ltd., Tokyo, pp. 2 - 96, 111 - 351 (in Japanese)."]}

Field experiments were conducted in 2016 and 2017 in Tennessee to evaluate the effects of a novel Bacillus thuringiensis (Bt)-transgenic toxin, Bt Cry51Aa2.834_16, on thrips (Thysanoptera: Thripidae) and tarnished plant bug, Lygus lineolaris (Palisot De Beauvois) (Hemiptera: Miridae), in cotton. Protection from thrips injury with the Bt trait was as good or better than an insecticide-based approach. The use of the Bt trait resulted in reduced numbers of immature tarnished plant bug, particularly large nymphs, and partial protection from plant bug injury. Cotton that expressed Bt Cry51Aa2.834_16 had greater yields than the non-Bt isoline when insecticides were not used. Although Bt Cry51Aa2.834_16 reduced the need for insecticide applications, foliar-applied insecticide applications were needed to provide adequate plant protection from tarnished plant bug. The currently recommended treatment thresholds for tarnished plant bug performed similarly well for Bt Cry51Aa2.834_16 and non-Bt isolines. Insecticide applications for tarnished plant bug increased fiber quality, while Bt Cry51Aa2.834_16 had minor effects. The Bt-transgenic toxin Cry51Aa2.834_16 is expected to reduce the need for insecticide applications targeting thrips and tarnished plant bug and could be a valuable addition to an overall insect management program in cotton.

Chemosensory proteins (CSPs) are soluble carrier proteins typically characterized by a six-helix bundle structure joined by two disulfide bridges and a conserved Cys spacing pattern (C1-X6-8 -C2-X16-21 -C3-X2 -C4). CSPs are functionally diverse with reported roles in chemosensation, immunity, development, and resistance. To expand our molecular understanding of CSP function in plant bugs, we used recently developed transcriptomic resources for Lygus lineolaris and Lygus hesperus to identify 17 and 14 CSP-like sequences, respectively. The Lygus CSPs are orthologous and share significant sequence identity with previously annotated CSPs. Three of the CSPs are predicted to deviate from the typical CSP structure with either five or seven helical segments rather than six. The seven helix CSP is further differentiated by an atypical C3-X3 -C4 Cys spacing motif. Reverse transcriptase PCR-based profiling of CSP transcript abundance in adult L. lineolaris tissues revealed broad expression for most of the CSPs with antenna specific expression limited to a subset of the CSPs. Comparative sequence analyses and homology modeling suggest that variations in the amino acids that comprise the Lygus CSP binding pockets affect the size and nature of the ligands accommodated.

Ecological speciation is often observed in phytophagous insects and their parasitoids due to divergent selection caused by host‐associated or temporal differences. Most previous studies have utilized limited genetic markers or distantly related species to look for reproductive barriers of speciation. In our study, we focus on closely related species of Lygus bugs and two sister species of Peristenus parasitoid wasps. Using mitochondrial DNA COI and genomewide SNPs generated using ddRADseq, we tested for potential effects of host‐associated differentiation (HAD) or temporal isolation in this system. While three species of Lygus are clearly delineated with both COI and SNPs, no evidence of HAD or temporal differentiation was detected. Two Peristenus sister species were supported by both sets of markers and separated temporally, with P. mellipes emerging early in June and attacking the first generation of Lygus, while P. howardi emerging later in August and attacking the second generation of their hosts. This is one of the few studies to examine closely related hosts and parasitoids to examine drivers of diversification. Given the results of this study, the Lygus‐Peristenus system demonstrates temporal isolation as a potential barrier to reproductive isolation for parasitoids, which could indicate higher parasitoid diversity in regions of multivoltine hosts. This study also demonstrates that incorporating systematics improves studies of parasitoid speciation, particularly by obtaining accurate host records through rearing, carefully delimiting cryptic species and examining population‐level differences with genomic‐scale data among closely related taxa.

Mechanistic species niche models were used to map the seasonal spatio-temporal dynamics of biological control pressure. Future climate scenarios were applied to these models to identify potential future trends in the patterns of biological control pressure through space and time during an annual seasonal cycle.Peristenus digoneutisLoan (Hymenoptera: Braconidae) is a parasitoid ofLygusHahn (Hemiptera: Miridae) species, important pests of glasshouse and field crops throughout Europe and North America. Consistent with theoretical expectations, the modelled potential range ofP. digoneutisexpanded polewards and contracted from its southern temperature range limits. However, its distribution did not change consistently across continents or countries. Locations near the outer limits of the current modelled distribution were more sensitive to changes in future climates than locations near the central core. Weekly climate suitability and stress maps were developed to provide insight into seasonal adjustments that accompany changes in the potential range of pest species and their natural enemies. Climate change may increase the number ofLygusgenerations in western Canada allowingP. digoneutisto establish in areas, where biological control attempts had failed in the past.

BACKGROUND Lygus lineolaris (Palisot de Beauvois) is a serious pest of cotton (Gossypium hirsutum L.) in Mississippi, particularly in the Delta region. This may be due to decreased insecticide susceptibility in that region. Research has revealed populations of L. lineolaris in the Delta region with high levels of insecticide resistance; however, comparisons with populations in the remainder of the state are limited. RESULTS Experiments were undertaken to compare the LC50 values and activities of detoxification enzymes of L. lineolaris populations. The results of these studies indicated that the LC50 values were not different between the Delta and Hills regions, but differences were significant between populations within and across regions. Results of the detoxifying enzyme activity assays revealed significantly higher esterase activity in the Delta region when compared with the Hills. Glutathione S-transferase activity was not different between regions, but differences within and across regions were significant. CONCLUSION The results indicated that glass-vial assays to determine and compare LC50 values may be less accurate than enzymatic assays for detecting insecticide susceptibility differences. Higher esterase activity is likely a contributing factor to the difficulties with managing L. lineolaris in the Mississippi Delta region. © 2015 Society of Chemical Industry.

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 LC(50) and LC(90) values for novaluron. Mean LC(50s) for glass vial bioassays ranged from 44.70 ± 3.58 to 66.54 ± 4.19 μg/vial, while mean LC(50s) for diet-incorporated bioassays ranged from 12.10 ± 0.77 to 17.63 ± 2.42 μg/200 ml of artificial diet. A comparison of LC(50) values from the same field population screened using both bioassay methods failed to show a relationship. LC(50) 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 LC(50) values than a historically susceptible population.

Astakines are hematopoietic cytokines originally isolated from crustaceans. We identified three astakine-like transcripts in the tarnished plant bug (Lygus lineolaris), LlAst-1, LlAst-2 and LlAst-3, containing prokineticin domains. Quantitative real-time PCR showed variation in expression patterns of astakines in different tissues and between sexes. Relative expression levels of LlAst-1 were highest in the fat bodies of females, while LlAst-2 expression was highest in the fat bodies of both males and females. LlAst-3 expression was higher in male legs compared with the female legs, but lower in all other tissues. Infection with the entomopathogenic fungus Beauveria bassiana slightly elevated LlAst-1 expression 48 h after infection in both males and females. In contrast, the expression levels of LlAst-2 and LlAst-3 were not significantly changed in males and females. Compared with 12:00 h, LlAst-1 level was higher in both sexes at 18:00 h and 00:00 h (midnight). By 6:00 h, the LlAst-1 level in females was significantly reduced while that in males remained high. LlAst-2 and -3 had highest relative expression levels in females at midnight but were significantly lower than in males at midnight and in both sexes at 18:00 h and 6:00 h. This is the first report of expression of astakine-like cytokines from insects.

In Manitoba, Canada, commercial soybeans and two types of field beans, navy and pinto, were sampled for plant bugs. At the centre and margins of 36 fields, sweep net and tap tray samples were taken weekly. In all three crops, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) comprised >78% and Adelphocoris lineolatus (Goeze) (Hemiptera: Miridae) Lygus Hahn, nymphs were 46% of the catch in trays and 23% in sweeps, but total Lygus catch in trays was >2% of that in sweeps. Catch/sample effort was similar at field centres and margins for both Lygus adults and nymphs. Lygus lineolaris reproduced and developed in all three crops. In field beans, Lygus adults were first collected in late vegetative and early pod set stages and late instar nymphs and adults were present from pod elongation until maturity – results consistent with immigration of first summer generation reproductive adults and development of the second generation in the crops. There was evidence of late season immigration of Lygus into all crops. There was no loss of seed quantity attributable to mirids in any of the crops; in field beans there was no evidence that mirids reduced seed quality.

Lygus bugs are highly polyphagous insect pests. In recent years, Lygus bugs have become more conspicuous on potato, Solanum tuberosum L., fields in the Pacific Northwest, particularly in the Lower Columbia Basin. There are concerns that direct feeding damage or potential pathogen transmission can reduce yield. Lygus species on potatoes in the region are collectively identified as 'Lygus bugs'. Overlapping physical traits and the fact that the same species exhibit morphological variations across a geographic range makes it difficult to identify Lygus to species level. Thus, in this study we used DNA barcodes in combination with morphological characters to identify Lygus species on potatoes. Three species were identified in the Lower Columbia Basin: Lygus hesperus (Knight) and Lygus elisus L. were the most common, whereas Lygus keltoni L. was the least common. Interspecific genetic distances among Lygus species were relatively low, ranging from 0.013 to 0.004. Neighbor-joining (NJ) tree clustered L. hesperus and L. elisus into two major clades, with L. keltoni forming a subclade within L. hesperus clade. Statistical parsimony analysis corroborated findings from phylogenetic analysis with L. keltoni and L. hesperus sharing one haplotype. Our study demonstrates the utility of integrating morphology and molecular markers in identifying morphologically similar species such as Lygus bugs. The study also serves as a fundamental step in contributing to developing suitable management strategies against Lygus bugs on potato.

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.

Lygus pratensis is a phytophagous pest responsible for yield losses in Bt alfalfa and other economic crops in Northwestern China. To better characterize Miridae at the genomic level, the complete mitochondrial (mt) genome of L. pratensis was sequenced and analyzed in this study. The mt genome was amplified via the polymerase chain reaction to generate overlapping fragments. These fragments were then sequenced, spliced, and analyzed to include the examination of nucleotide composition, codon usage, compositional biases, protein-coding genes (PCGs), and RNA secondary structures. Phylogenetic relationships between L. pratensis and other species in different Heteroptera families were also examined. The mt genome was found to be a typical circular genome with a length of 16,591 bp and a total AT content of 75.1%, encoded for 13 PCGs, 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (lrRNA and srRNA), and a noncoding control region. The nucleotide composition of the entire mt genome was heavily biased toward A and T. All of the tRNAs were predicted to have classic clover leaf structures, but three of the tRNAs (tRNAAsn, tRNAHis, tRNAHis) were missing the TΨC loop. The control region (2,017 bp), which was found to be located between 12S and tRNAIle, contained three tandem repeat elements. Phylogenetic analyses showed that L. pratensis is closely related to the other three examined Lygus bugs, and that it is a sister group to Apolygus and Adelphocoris. This study confirms the usability of the mt genome in phylogenesis studies pertaining to the Lygus genus, within Miridae.

Members of the Miridae (Lygus lineolaris Palisot de Beauvois and Pseudatomoscelis seriatus Reuter) and Pentatomidae (Acrosternum hilare Say, Euschistus servus (Say), Euschistus tristigmus (Say), Euschistus quadrator Rolston, Oebalus pugnax (F.), Piezodorus guildinii (Westwood), and Thyanta custator accerra McAtee) comprise a piercing-sucking insect complex that continues to plague multiple crops, including cotton. All these species have been associated with pathogen transmission. Breaching of boll carpel walls facilitates introduction of pathogens, and it is unknown whether stylets of these pests can fully penetrate carpel walls. Thus, stylet penetration estimates are needed and have been the focus of the present work. Stylet penetration estimates for L. lineolaris were significantly deeper than P. seriatus. Among the Pentatomidae, highest mean penetration was estimated for E. servus followed by A. hilare, yet A. hilare possessed a longer rostrum. Similarly, O. pugnax showed deeper penetration estimates than P. guildinii yet P. guildinii possessed a longer rostrum. Thus, rostrum length should not be equated to penetration potential. Pseudatomoscelis seriatus and L. lineolaris both infest early-season cotton, and the ranges of observed penetration indicate these insects, as well as the Pentatomidae, can breach the walls of critical pinhead squares and smaller bolls. The insects addressed herein affect a myriad of crops globally, and penetration estimates allow identification of growth stages susceptible to feeding and disease transmission.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), is a major pest of cotton (Gossypium hirsutum L.) in the state of Mississippi. Economic data indicate that L. lineolaris is a more serious pest of cotton in the Delta region of Mississippi than in the Hills region; however, little data exist comparing the two populations. Two experiments were undertaken to compare L. lineolaris from these two geographically distinct regions. In the first experiment, colonies of L. lineolaris from each region were reared in the laboratory under controlled conditions and measurements of development time, survivorship, fecundity, and hatch rate were compared. The geographic region of origin had no effect on any of the variables measured; however, the diet used for rearing had a significant effect on all variables except hatch rate. In the second experiment, part of the cox1 gene of the L. lineolaris mitochondrial genome was compared between the two populations to examine possible genetic differences between L. lineolaris from the two regions of Mississippi. Data revealed two cox1 clades in the Delta region and only one cox1 clade in the Hills region. Taken together, the data do not explain the reason for the differences in the severity of damage to cotton in the two regions.

A segment of the nuclear 28S rRNA gene was compared among six species of Lygus [Lygus hesperus (Knight), Lygus keltoni (Schwartz), Lygus borealis (Kelton), Lygus elisus (Van Duzee), Lygus lineolaris (Palisot de Beauvois), and Lygus vanduzeei (Knight)]. The DNA sequences were separate into three main groups. The LL group contains L. lineolaris and L. vanduzeei. Group LBLE is composed of L. elisus and most of L. borealis. Group LH includes L. hesperus and most of L. keltoni. Some L. keltoni were part of the LBLE group and some L. borealis were part of the LH group. The 28S region does not contain sufficient genetic polymorphism to delineate species. The apparent polyphyly of L. borealis and L. keltoni could reflect historic interbreeding, recent development of a hybrid swarm, or highlight inadequacies of morphospecies identification.

Remote sensing was used in a series of experiments over a three-year period to obtain spectral reflectance data for studying differences in vegetation indices between grasses, broadleaf plants, and grass/broadleaf plant mixtures. Selected non-crop winter and spring host plants of tarnished plant bug, Lygus lineolaris, were planted in field-plot experiments. Multispectral reflectance data were aerially acquired with both a Real-Time Digital Airborne Camera System (RDACS) sensor and Geospatial Systems (Duncan Tech) MS-2100 multispectral camera. The following six vegetation indices of spectral reflectance were evaluated in this study: normalized difference vegetation index, ratio vegetation index, green normalized difference vegetation index, green vegetation index, green ratio vegetation index, and Ashburn vegetation index. Vegetation indices calculated with imagery data for the grasses and broadleaves differed significantly; there appeared to be more discriminating differences between vegetation indices for grasses and broadleaf plants when the indices were based on a combination of green and near infrared or green and red spectral bands than when the indices were based on red and near infrared spectral bands. Insect data from these studies confirm that tarnished plant bug prefers broadleaf host plants, but can use Italian ryegrass for food and reproduction. The narrow temporal window of host suitability for Italian ryegrass may limit its significance. Herbicide destruction of broadleaf host plants in early spring prevented the tarnished plant bug population increases that occurred in untreated plots. Findings of this study would be useful in site-specific vegetation management decisions in programs such as the prototypical area-wide tarnished plant bug management experiment conducted in the Delta region of Mississippi.

* Lygus rugulipennis Poppius, 1911 Throughout the study area collected in large numbers., Published as part of TASZAKOWSK, Artur & PASI��SKA, Agnieszka, 2017, New data on the occurrence of terrestrial true bugs (Hemiptera: Heteroptera) in Pieniny Mountains, pp. 1-13 in Fragmenta Faunistica 60 (1) on page 6, DOI: 10.3161/00159301FF2017.60.1.001, http://zenodo.org/record/6251980

Lygus pratensis (Linnaeus, 1758) Throughout the study area collected in large numbers., Published as part of TASZAKOWSK, Artur & PASI��SKA, Agnieszka, 2017, New data on the occurrence of terrestrial true bugs (Hemiptera: Heteroptera) in Pieniny Mountains, pp. 1-13 in Fragmenta Faunistica 60 (1) on page 6, DOI: 10.3161/00159301FF2017.60.1.001, http://zenodo.org/record/6251980

* Lygus wagneri Remane, 1955 Throughout the study area collected in large numbers. Remarks: Specimens of the genus Lygus were collected in large numbers. Identification of L. pratensis and L. rugulipennis is not problematic, but L. wagneri and Lygus punctatus (Zetterstedt, 1838) are difficult to distinguish from each other. These species have similar coloration, which is characterized also by very high variability. The differences in structure of paramers, which used by Wagner & Weber (1964), were not included as distinguishing taxonomic features in the most recent revision of Palearctic species of the genus Lygus (Aglyamzyanov 2009). The shape of vesical spicula, which clearly distinguishes species within the genus, in this case is a little valuable feature, because it is very similar in both species (Fig. 2A, B). The puncturation of the corium (Fig. 2C) is the only reliable feature that distinguishes both species (Aglyamzyanov 2009): L. punctatus ��� puncturation of the corium is scattered and uneven, distance of punctures from each other on clavus is clearly shorter than on the middle of corium; L. wagneri ��� puncturation of the corium is dense and uniform, distance of points from each other on clavus is the same as on the middle of corium (Fig. 2C). This feature is poorly visible in the light microscope, therefore the photographs taken on a scanning electron microscope are most useful., Published as part of TASZAKOWSK, Artur & PASI��SKA, Agnieszka, 2017, New data on the occurrence of terrestrial true bugs (Hemiptera: Heteroptera) in Pieniny Mountains, pp. 1-13 in Fragmenta Faunistica 60 (1) on page 6, DOI: 10.3161/00159301FF2017.60.1.001, http://zenodo.org/record/6251980, {"references":["WAGNER E. & WEBER H. H. 1964. Heteropteres Miridae. Faune de France. 67. Federation Francaise Des Societes De Sciences Naturelles Office Central De Faunistique, Paris, 589 pp.","AGLYAMZYANOV R. S. 2009. Revision of the Palaearctic species of Lygus Hahn, 1833 (Heteroptera: Miridae). Entomologische Zeitschrift mit Insekten-Borse, 119 (6): 249 - 276."]}

Author(s): Mueller, Shannon C; Summers, Charles G; Goodell, Peter B | Abstract: Correct identification of captured Lygus bugs and similar-looking insects is a key to accurate research and pest control. This publication and its companion publication (Key Features of Common Lygus Species%) give point-by-point instructions.

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.

Passive mechanisms of mate guarding are used by males to promote sperm precedence with little cost, but these tactics can be disadvantageous for their mates and other males. Mated females of the plant bug Lygus hesperus are rendered temporarily unattractive by seminal fluids containing myristyl acetate and geranylgeranyl acetate. These antiaphrodisiac pheromones are gradually released from the female’s gonopore, declining until they no longer suppress male courtship. Because starting quantities of these compounds can vary widely, the repellant signal becomes less reliable over time. Evidence was found of a complimentary mechanism that more accurately conveys female mating status. Once inside the female, geranylgeranyl acetate is progressively converted to geranylgeraniol then externalized. Geranylgeraniol counteracts the antiaphrodisiac effect despite having no inherent attractant properties of its own. This is the first evidence for such an anti-antiaphrodisiac pheromone, adding a new element to the communication mechanisms regulating reproductive behaviors. DOI: http://dx.doi.org/10.7554/eLife.24063.001, eLife digest In many animal species, males guard females to prevent rivals from mating so that they can be sure that they fathered the female’s offspring. Some guarding methods work even when the male is not present. For example, the semen of some male insects contains chemicals known as antiaphrodisiacs that repel other males from females who have recently mated. Over the course of several days or weeks, the females expel or degrade the antiaphrodisiacs, making themselves attractive to other mates again. How long it takes to eliminate the antiaphrodisiacs depends on how much of the chemicals were deposited in the first place. Therefore, males could gain an advantage in fertilizing more eggs by depositing excess antiaphrodisiac to make the females unattractive to other mates for a long time. The Western tarnished plant bug (Lygus hesperus) is an agricultural pest that targets cotton, strawberries and other crops. One antiaphrodisac had already been identified in the semen of male Lygus bugs. To investigate whether the males produced any others, Brent et al. tested the molecules emitted by recently mated females. This search identified another potential antiaphrodisiac. However, females are able to convert this second chemical into a third one that neither attracts nor repels males. This “anti-antiaphrodisiac” acts against the males’ two antiaphrodisiacs, and allows the females to more accurately signal when they are ready to mate again, giving them more control over their reproduction. Anti-antiaphrodisiacs were not previously known to exist, but now that scientists know where to look, more are likely to be found in other species. A better understanding of how different chemicals interact to influence the mating behavior of insects could also lead to new methods of targeting pests of crops, which are safer for the environment than existing chemical pesticides. DOI: http://dx.doi.org/10.7554/eLife.24063.002

Increased homogeneity of agricultural landscapes in the last century has led to a loss of biodiversity and ecosystem services. However, management practices such as wildflower borders offer supplementary resources to many beneficial arthropods. There is evidence that these borders can increase beneficial arthropod abundance, including natural enemies of many pests. However, this increase in local habitat diversity can also have effects on pest populations, and these effects are not well-studied. In this study, we investigated how wildflower borders affect both natural enemies and pests within an adjacent strawberry crop. Significantly more predators were captured in strawberry plantings with wildflower borders versus plantings without wildflowers, but this effect depended on sampling method. Overall, herbivore populations were lower in plots with a wildflower border; however, responses to wildflower borders varied across specific pest groups. Densities of Lygus lineolaris (Tarnished Plant Bug), a generalist pest, increased significantly in plots that had a border, while Stelidota geminata (Strawberry Sap Beetle) decreased in strawberry fields with a wildflower border. These results suggest that wildflower borders may support the control of some pest insects; however, if the pest is a generalist and can utilize the resources of the wildflower patch, their populations may increase within the crop.

The tarnished plant bug, Lygus hesperus (Heteroptera: Miridae) is a pest on more than 150 plant species including field, fruit and vegetable crops. Our investigation on rose plants at Taif, Saudi Arabia observed that there are individuals of Lygus sp. during the flowering period. We morphologically identified these as Lygus hesperus. Consequently, this pest is considered as an exotic species in Saudi Arabia and it may be transformed from a minor to a major pest. We studied the length and sequencing of the ITS1 region and its flanking: 18S rRNA and 5.8S genes in this species. Biological and demographic parameters also were studied on two host plant species: green bean pods and rose flower buds. Sequencing of PCR product of ITS1 and its flanking in nine individuals of L. hesperus showed identical sequences for this fragment and obtained 743 bp for the complete ITS1. Biological data showed that the tested host source had an influence on all biological parameters except sex ratio, male longevity, preoviposition and postoviposition periods for females. The green bean pods as a host resulted in higher hatchability, shorter egg duration and nymphal development time, higher survival and fecundity, and longer female longevity. Therefore more favorable demographic parameters of L. hesperus were achieved on green bean pods where it had the shortest T and DT values as well as the highest GRR, rm, λ and R0 values. Additional biological data will be required on other plant hosts in the laboratory or field to estimate population growth and pest potential of L. hesperus in Saudi Arabia. Surveying of parasitoids and predators associated with this invasive insect pest are also desirable.

BACKGROUND The invasive brown marmorated stink bug, Halyomorpha halys (Stal) (Hemiptera: Pentatomidae), has emerged as a key pest in mid-Atlantic peach production. Current management of H. halys has disrupted IPM programs by relying exclusively on frequent, repeated, season-long insecticide applications. We developed a behaviorally-based tactic termed IPM-CPR (Crop Perimeter Restructuring) that utilizes border sprays for H. halys, groundcover management for Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) and mating disruption for Grapholita molesta (Busck) (Lepidoptera: Tortricidae). RESULTS IPM-CPR reduced insecticide usage by 25–61%. Generally there was less, and at times significantly less, catfacing injury (attributable to H. halys) in peaches in the IPM-CPR blocks relative to the standard, and minimal differences in injury due to G. molesta or L. lineolaris. These results suggest that perimeter applications of insecticides exploit the border-arrestment behavior of H. halys by controlling them at the orchard edge, reducing damage throughout the block. CONCLUSION IPM-CPR significantly reduces the area managed by growers for control of H. halys, while simultaneously managing key pests at levels equal to current grower standard practices. This approach brings IPM tactics back into the orchard system after disruption by the invasive H. halys and potentially supports beneficial insects. © 2014 Society of Chemical Industry

A laboratory experiment was performed to compare fitness parameters of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations collected from the Hills and Delta regions of Mississippi. Each population was split into two cohorts to be reared on cotton or artificial diet to make comparisons of food source and region of collection. Each population was maintained separately and allowed to mate. Nymphal survivorship from the F1 generation of each population from each region and food source was compared. Parameters measured included development times to fourth instar, fifth instar and adult, total nymphal survivorship, fecundity, and fertility. Populations collected from the Delta region and reared on cotton developed significantly faster at all life stages than other populations. Tarnished plant bugs from the Hills reared on cotton developed significantly slower than other populations, except those from the Hills reared on artificial diet. Populations reared on diet had significantly higher survivorship than those reared on cotton. Tarnished plant bug populations from the Delta region laid significantly more eggs per female per day than those from the Hills region. Populations reared on cotton also laid significantly more eggs per female per day than those reared on diet. Populations collected in the Delta region laid significantly more viable eggs per female per day than those from the Hills region. Tarnished plant bugs reared on cotton produced significantly more nymphs per female per day than those reared on diet. These data indicate there are differences in several fitness parameters between tarnished plant bug populations from the Hills and Delta regions of Mississippi.

Alfalfa trap crops are currently used to manage Lygus spp. in organic strawberry fields on the California Central Coast. The retention of Lygus spp. in alfalfa creates aggregated distributions that provide improved opportunities for biological control by the introduced parasitoid Peristenus relictus (Ruthe). The abundance and distribution of P. relictus between two trap crops separated by 50 strawberry rows were analyzed in 2008 and 2010. Parasitism of Lygus spp. nymphs by P. relictus (measured by larval abundance and % parasitism) was greatest in alfalfa trap crops compared with strawberry rows. A significantly positive correlation between host nymphs and P. relictus larvae in and between trap crops was found. Movement of P. relictus adults from a marked alfalfa trap crop into adjacent strawberry rows or trap crops was also studied in 2008 and 2009 using a chicken egg-albumin enzyme-linked immunosorbent assay mark-capture technique. In 2008 and 2009, 85 and 49% of protein-marked wasps were captured from central trap crops, respectively, indicating that alfalfa trap crops act as a concentrated "host-density anchor" in organic strawberry fields.

Background The timing and location of Lygus lineolaris (Palisot de Beauvois) dispersal into cotton is important to accurate and effective scouting and management. In the spring, L. lineolaris populations develop on non-crop weeds surrounding cotton fields. As weeds senesce, L. lineolaris migrate into susceptible cotton at the squaring stage. Given this predictable temporal colonization pattern, scouting efforts to inform insecticide interventions may be improved with a spatiotemporally targeted sampling recommendation. Methods Using a geospatial approach, we tracked L. lineolaris populations at 352 unique sites along transects located in commercial North Carolina cotton fields over two consecutive years. Standardized sweep samples of L. lineolaris adults and nymphs were taken at each site. To relate the abundance of L. lineolaris to the spatial structure of cotton fields, the distance of the sample from the field edge and the edge-to-area ratio of each field were analyzed using GIS. All counts were related to accumulated degree days at each sample time to document seasonal progression of L. lineolaris abundance and temporal host utilization (i.e., weeds vs. cotton). Counts were also related to spatially structured scouting recommendations used in North Carolina. Results Nymph counts were significantly affected by accumulated degree days and distance from field edge. Higher adult counts were found in fragmented fields with greater edge-to-area ratios. Our results show that L. lineolaris nymphs were more spatiotemporally variable than adults, thereby being more likely to affect scouting accuracy when using sweep samples alone. We found that samples closer to the field edge likely increase the probability of being over the North Carolina L. lineolaris threshold.

The western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), can cause serious losses to strawberry, vegetables, and field crops in the western US. Often, fifth instars are noticed walking at the perimeter of crop fields. However, little is known of their walking capacity and dispersal. A series of laboratory and field studies were used to record the walking capacity of fifth instars. Starved nymphs moved farther (∼2×) than non-starved individuals in a laboratory. Fifth instars also traveled farther (as many as 12 m in 15 minutes) as surface temperature warmed. Wind velocity had no effect on nymphal movement.

Field trials conducted in 2008 and 2009 investigated whether plot size affects incidence of white flower anther injury by tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)) in host plant resistance (HPR) evaluations. The three cotton lines evaluated in the trial included a susceptible frego bract line (RBCDHGPIQH-197) and 2 standards, SureGrow (SG) 105 and Deltapine (DP) 393. Samplers monitored white flower anther injury between single row mini-plots embedded within multiple row max-plots. A sub-section of the max-plots was sprayed with insecticides to evaluate these tactics on altering the incidence of white flower anther injury. Plant bug numbers were very low in 2008, while infestation levels were higher in 2009. Significantly higher numbers of flowers with anther injury were observed in both years in the susceptible frego bract line compared to SG 105 and DP 393 lines. In both years, anther injury levels were similar in the max- and mini-plots, with lower levels observed in max-sprayed plots. The white flower monitoring procedure is a consistent indicator of adult plant bug preferences and is not influenced by plot size or interspersions of cultivar lines among plots.

A field experiment was conducted in Stoneville, MS, during 2010 and 2011 to investigate the impact of varietal maturity, planting date, and insecticide application on tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations and damage in cotton. Four planting dates were selected to encompass the cotton-planting period in Mississippi. An early and late maturing variety were planted at each planting date, and each variety and planting date combination was either sprayed or unsprayed for tarnished plant bugs. Plots were sampled weekly from first square until physiological maturity. Plots were harvested at the end of the season. Early planting dates had lower densities of tarnished plant bug and required fewer insecticide applications than the later planting dates. Mid-April to early May planting dates sustained less yield loss from tarnished plant bug than mid-May to late-May planting dates. Tarnished plant bug had less impact on yield of the early maturing variety than on the late maturing variety. The sprayed plots yielded more than unsprayed plots. These data demonstrate that later plantings of cotton in the Mississippi Delta are likely to experience yield losses from tarnished plant bug and need to be sprayed more compared with early cotton plantings. As a result, growers should manage their crop for earliness through planting date and varietal selection.

The plant bugs Lygus hesperus, Lygus lineolaris, and Lygus elisus (Hemiptera: Miridae) are major pests of many agricultural crops in North America. Previous studies suggested that females release a sex pheromone attractive to males. Other studies showed that males and females contain microgram amounts of (E)-4-oxo-2-hexenal, hexyl butyrate, and (E)-2-hexenyl butyrate that are emitted as a defense against predators. Usinggaschromatography-massspectrom- etry, we found that female L. lineolaris and L. elisus have a 4:10 ratio of hexyl butyrate to (E)-2-hexenyl butyrate that is reversed from the 10:1 ratio in female L. hesperus (males of the three species have ~10:1 ratio). These reversed ratios among females of the species suggest a behavioral role. Be- cause both sexes have nearly equal amounts of the major volatiles, females should release more to attract males. This expectation was supported because L. hesperus females re- leased more hexyl butyrate (mean of 86 ng/h) during the night (1800-0700 hours) than did males (

In insects, the perception and discrimination of odorants requires the involvement of odorant-binding proteins (OBPs). To gain a better molecular understanding of olfaction in the agronomic pest Lygus lineolaris (the tarnished plant bug), we used a transcriptomics-based approach to identify potential OBPs. In total, 33 putative OBP transcripts, including the previously reported Lygus antennal protein (LAP), were identified based on the characteristic OBP Cys signature and/or sequence similarity with annotated orthologous sequences. The L. lineolaris OBP (LylinOBP) repertoire consists of 20 ‘classic’ OBPs, defined by the spacing of six conserved Cys residues, and 12 ‘Plus-C’ OBPs, defined by the spacing of eight conserved Cys and one conserved Pro residue. Alternative splicing of OBP genes appears to contribute significantly to the multiplicity of LylinOBP sequences. Microarray-based analysis of chemosensory tissues (antennae, legs and proboscis) revealed enrichment of 21 LylinOBP transcripts in antennae, 12 in legs, and 15 in proboscis, suggesting potential roles in olfaction and gustation respectively. PCR-based determination of transcript abundance for a subset of the LylinOBP genes across multiple adult tissues yielded results consistent with the hybridization data.

Mirid bugs (Hemiptera: Miridae) are an important group of insect pests on many agricultural crops, including cotton, legumes, cereals, vegetables, and fruits (Wheeler, 2001). The adults and nymphs feed via piercing and sucking mouthparts on the terminal meristems, young flower buds, fruits (including cotton bolls), and other tissues, often causing the formation of bushy plants, the abscission of flower buds and fruits, and the malformation of mature fruits (Wheeler, 2001). These injuries greatly reduce crop yield and quality, causing serious economic losses in years of high infestation levels. Unlike many other common piercing/sucking insects (e.g., aphids, planthoppers, whiteflies) that are vascular feeders, mirid bugs are mostly considered ‘lacerate-and-flush’ feeders (Miles, 1972; Backus, 1988). More specifically, mirid bugs use their stylets to first lacerate the plant cells, simultaneously secreting a watery saliva into the ruptured cellular matter, and then ingest the resulting lacerated/macerated ‘soup’ (Backus et al., 2007). However, certain species – e.g., Helopeltis clavifer (Walker) – move their stylets very little while probing and use the watery saliva itself to macerate plant tissue, a strategy that is termed ‘macerate-and-flush’ feeding (Miles, 1987; Miles & Taylor, 1994). As both feeding strategies of mirid bugs are apparently related to the presence of digestive enzymes in their saliva, knowledge of the extra-oral digestion of mirid bugs is important for fully understanding the interactions between mirid bugs and their host plants (CelorioMancera et al., 2008). Among the various digestive enzymes in the salivary glands of mirid bugs, polygalacturonase (PG) is the most important in the induction of visible plant injury. This enzyme catalyzes the hydrolysis of the a-1,4-glycosidic linkages in polygalacturonic (pectic) acid in the cell walls. Strong & Kruitwagen (1968) determined the presence of PG in the salivary glands of Lygus hesperus Knight, and Strong (1970) further found that the plant injury caused by L. hesperus was mainly due to the activity of PG, rather than tomechanical damage caused by stylet probing. Shackel et al. (2005) injected a crude and partially purified PG solution into alfalfa (Medicago sativa L.) florets and cotton (Gossypium hirsutum L.) flowers and observed damage similar to that caused by Lygus feeding, whereas the control plant injected with a solution lacking PG showed no damage. Meanwhile, Celorio-Mancera et al. (2008) compared the damage of an enzymatically active PG and a mutant inactive PG in alfalfa florets and found that the former elicited Lygus damage symptoms, whereas the latter did not. These two recent studies support the results of previous studies (Strong & Kruitwagen, 1968; Strong, 1970) and highlight the significance of PG proteins in the formation of plant symptoms caused bymirid bug feeding. In China, the mirid bug Apolygus lucorum (Meyer-D€ ur) is a common polyphagous pest (Cao & Wan, 1983; Lu & Wu, 2008). Since the late 1990s, with the wide-scale adoption of transgenic Bt (Bacillus thuringiensis Berliner) cotton and the associated reduction of insecticide use in this crop, A. lucorum population levels have drastically increased, resulting in high infestations in such crops as cotton, local Chinese dates, cherries, grapes, apples, and pears (Lu et al., 2010; Lu &Wu, 2011). Although A. lucorum causes the same damage symptoms as other common mirid bug species (e.g., Lygus spp.) (Lu & Wu, 2008), the role of its salivary gland digestive enzymes in the formation of plant damage symptoms has not been determined. In addition, although the micropressure probe system is suitable for simulating mirid bug feeding on transplanted plants in the laboratory (Shackel et al., 2005), it requires a specialized micropressure probe system which is not suitable for assay*Correspondence: E-mail: yhlu@ippcaas.cn

Despite numerous studies examining feeding injury to cotton (Gossypium spp.) caused by different stages of Lygus hesperus Knight, no consistent trends are apparent. One explanation for inconsistencies among previous results is failure to account for important sources of biological variation. Because it was only recently recognized that feeding behavior and injury differed among adults of different physiological ages, this source of variance was not controlled in earlier studies of Lygus stage-dependent injury. We incorporated this knowledge into video assays and greenhouse experiments to compare feeding behaviors, within-plant distributions, and injury to cotton plants among L. hesperus nymphs and prereproductive adults. Laboratory behavior assays indicated third instars exhibited more stylet-probes, but of shorter duration, compared with prereproductive adults. Numbers and duration of stylet-probes by fifth instars were intermediate to those of third instars and adults. Total time spent stylet-probing was similar among the insect age-classes. On whole plants, third instars tended to reside within the bracts of squares (flower buds) >3 mm in diameter, whereas fifth instars and adults tended to frequent the plant terminals. Adults were more likely than third or fifth instars to be located off the plants at any given observation. Plants exposed to fifth instars exhibited more square abscission and retained fewer squares 3-6 mm in diameter than did plants exposed to third instars or adults. Our results indicated that fifth instars were more injurious to cotton than third instars or prereproductive adults, and that differences in feeding injury corresponded with within-plant distributions exhibited by different L. hesperus age-classes.