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The direct effect of Palmer amaranth, Amaranthus palmeri Watson, on cotton growth and development is well documented, but its indirect effect through harboring feeding insects is less understood. Palmer amaranth emerged with cotton and remaining in the field for 30 days increased tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations compared with a weed-free system. Weedy systems noted up to 49% more damaged terminals than weed-free systems, with cotton yield decreasing as damaged terminals increased at one of two locations. Thrips (Thysanoptera: Thripidae) populations were effectively controlled with Aeris® (Bayer, St. Louis, MO) seed treatment (imidacloprid + thiodicarb at 0.375 mg active ingredient per seed), but there was no correlation between thrips infestations and increasing damaged cotton terminals. However, Aeris seed treatment significantly reduced the occurrence of damaged cotton terminals. In a second experiment, Palmer amaranth infesting an area adjacent to a weed-free cotton field had maximum damaged terminals of 51% on the cotton row proximal to the weedy area, with the distal cotton row (44 m away) having 8% terminal damage. Cotton yield significantly decreased as damaged terminals increased. A final bioassay experiment further evaluated the influence of seed treatment on tarnished plant bug feeding impacting cotton seedlings. With Aeris seed treatment, tarnished plant bug mortality was 97%, compared with 37% for nontreated seed. Results suggest tarnished plant bug infestations increased where Palmer amaranth was present in cotton fields. Additionally, greater Palmer amaranth infestations led to an increase in damaged cotton terminals and lower yields.

Crop diversification often promotes farm sustainability. However, proper management of newly introduced crops is difficult when pests are unknown. Characterizing herbivore dynamics on new crops, and how they respond to agronomic factors, is crucial for integrated pest management. Here we explored factors affecting Lygus spp. (Hemiptera: Miridae) herbivores in quinoa crops of Washington State. Quinoa is a newly introduced crop for North America that has multiple varieties and a range of agronomic practices used for cultivation. Through arthropod surveys and discussions with growers, we determined that Lygus spp. was the most abundant insect herbivore and likely contributed to low quinoa yields in previous seasons. We assessed how different varieties (Pison and QQ74), irrigation regimes (present and not), and planting methods (direct-seeded and transplanted) affected Lygus population dynamics. Lygus phenology was correlated with timing of quinoa seed-set in July and August, corresponding to a period when quinoa is most susceptible to Lygus. Both irrigation and planting manipulations had significant effects on Lygus abundance. Irrigation reduced Lygus abundance compared with nonirrigated plots in 2018. Planting method had a significant effect on Lygus populations in both 2017 and 2018, but effects differed among years. Variety had a significant effect on Lygus abundance, but only in nonirrigated plots. Overall, our study shows that Lygus is a common insect herbivore in quinoa, and careful selection of variety, planting method, and irrigation regime may be key components of effective control in seasons where Lygus abundance is high.

Lygus genus (Fig. 2, node 11). Lygus species are economically important group of insects in many agro-ecosystems (Shrestha et al. 2007). This genus comprises 163 species in the world (Schuh 2002 –2013), where three species have been recorded from Iran (Aukema 2020). The genus Lygus was recovered as a monophyletic group according to all analyses, with strong support (IW= 88%, EW= 86%). The monophyly of the genus Lygus was found in the previous studies based on morphological, molecular and combine data sets (e.g., Schwartz & Foottit 1998; Kim & Jung 2019)., Published as part of Zamani, Mozhgan & Hosseini, Reza, 2022, A phylogenetic study of the relationships within Mirinae subfamily (Insecta: Heteroptera: Miridae) based on specimens from Northern Iran: Insight into analyses of genera complexes, pp. 101-127 in Zootaxa 5200 (2) on page 105, DOI: 10.11646/zootaxa.5200.2.1, http://zenodo.org/record/7256717, {"references":["Shrestha, R., Parajulee, M. N. & Grimson, M. J. (2007) SEM Ultrastructure study of Lygus hesperus (Knight) (Hemiptera: Miridae). Available from: http: // wcrc. confex. com / wcrc / 2007 / techprogram / P 2024. HTM (accessed 10 Ocotber 2022)","Schuh, R. T. (2002 - 2013) On-line systematic catalog of plant bugs (Insecta: Heteroptera: Miridae). The American Museum of Natural History, New York, New York. Available from http: // research. amnh. org / pbi / catalog (accessed 10 October 2022)","Aukema, B. (2020) Catalogue of Palaearctic Heteroptera. Naturalis Biodiversity Center. Available from: https: // catpalhet. linnaeus. naturalis. nl / (accessed 20 August 2020)","Schwartz, M. D. & Foottit, R. G. (1998) Revision of the Nearctic species of the genus Lygus Hahn, with a review of the Palearctic species (Heteroptera: Miridae). Memoirs of Entomology International, 10, 1 - 428.","Kim, J. & Jung, S. (2019) Phylogeny of the plant bug subfamily Mirinae (Hemiptera: Heteroptera: Cimicomorpha: Miridae) based on total evidence analysis. Systematic Entomology, 44 (4), 686 - 698. https: // doi. org / 10.1111 / syen. 12348"]}

Tarnished plant bug, Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae), has become a primary pest of cotton in the Midsouthern United States. Insect growth regulators such as novaluron are an important part of L. lineolaris management. While novaluron is lethal to nymphs, it does not kill adults, so it has been used when nymphs are the primary stage present. However, cotton yield protection was observed from an application of novaluron when adults were the predominant stage present. To explain this, a series of studies were conducted to examine sublethal impacts of novaluron to L. lineolaris adults. Novaluron ingestion by adults reduced hatch rate and sometimes reduced oviposition rate. Ingestion by either males or females reduced hatch rates, but the reduction was greater from female exposure. Contact exposure of adults with novaluron residues within 1 d of application reduced hatch rate by about 50%, but the impact on oviposition was inconsistent. A field study showed reduced hatch rate from contact exposure to mixed-age natural populations, but the overall net reproductive rate was not reduced. Surface exposure of eggs to novaluron did not reduce hatch rate. Overall, exposure of tarnished plant bug adults to novaluron, regardless of adult age or exposure route, reduced egg viability. However, the impact on oviposition rate and net reproductive rate varied with adult age and exposure route. This understanding of sublethal impacts of novaluron, in addition to lethal impacts on nymphs, should be considered when choosing application times to maximize effects on L. lineolaris populations.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important insect pest in cotton that feeds on reproductive fruit, contributing to yield loss. Economically damaging infestations of L. lineolaris have doubled in Virginia since 2013. Escalation of L. lineolaris abundance may increase Fusarium hardlock disease observed in this region, compounding economic losses. Research has linked Fusarium hardlock with fungal species Fusarium verticillioides and F. proliferatum. Field and greenhouse experiments were performed to investigate (i) Fusarium hardlock occurrence in field plots managed and unmanaged for L. lineolaris, (ii) severity of F. verticillioides infection of cotton bolls with and without the presence of L. lineolaris feeding in a greenhouse setting, and (iii) Fusarium species composition and prevalence within field-collected L. lineolaris and cotton lint with and without insect feeding injury and hardlock symptoms present. Nearly twice the amount of hardlock (i.e., proportion of hardlocked locules) occurred in field-collected bolls with L. lineolaris feeding symptoms (0.40 ± 0.02) compared with bolls without (0.21 ± 0.01). Based on real-time quantitative PCR, cotton bolls exposed to F. verticillioides inoculum and caged with L. lineolaris adults had greater levels of F. verticillioides DNA compared with untreated bolls. F. proliferatum, F. verticillioides, and F. fujikuroi were isolated from field-collected L. lineolaris and hardlocked cotton lint at harvest. These findings suggest that the presence of L. lineolaris is associated with an increased risk of Fusarium hardlock in Southeastern cotton, and both should be carefully managed using timely insecticide applications and cultural control practices to minimize yield loss.

Lygus spp. are major pests of the California strawberry industry and have prompted growers to purchase and use machines called “bug vacuums” to mitigate damage throughout the production season. The...

BACKGROUND The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), has emerged as a major pest of cotton, Gossypium hirsutum L, in the mid-southern USA. In the early 1990s L. lineolaris populations developed resistance to several classes of conventional insecticides, increasing the need for insecticides with alternative modes of action such as insect growth regulators (IGRs) for integrated pest management (IPM). The benzoylphenyl urea (BPU) class of IGRs acts by disrupting the growth and development of immature stages of insects, but little is known about its impact on adult stages. RESULTS The effect of novaluron (Diamond™ 0.83EC), a BPU with known chitin synthesis inhibitor activity, was investigated on adult females of L. lineolaris. Treatment of 1-day-old adults with 600 ppm of novaluron in the diet prevented oviposition, while treatment of older females had no impact on oviposition. Oral novaluron exposure of adults of all ages reduced the viability of eggs laid. Novaluron treatment caused ultrastructural changes in the ovaries of 1-day-old adults (48 h post exposure), distorting the follicular epithelial cell architecture of developing oocytes. Additionally, novaluron treatment decreased the chitin content in ovarian tissue. CONCLUSION Our results suggest that chitin or chitin-like components in the developing ovaries of adult L. lineolaris are a target of IGRs such as novaluron, but its activity is specific to a critical time during development. This enhances our understanding of the effects of BPUs on adult insects and could lead to incorporation of IGRs in IPM for controlling adult insect pest populations in the field. © 2020 Society of Chemical Industry.

Spotted-wing drosophila (Drosophila suzukii(Matsumura) (Diptera: Drosophilidae)) is a pest of tender fruit and berry crops because female flies oviposit in ripening fruit. Frequent insecticide applications are needed for control during fruit ripening, with few noninsecticide options available. The effect of interplanting peppermint (Mentha × piperitaLinnaeus (Lamiaceae)) in strawberry (Fragaria × ananassaDuchesne (Rosaceae)) onD. suzukiifruit infestation was investigated because peppermint essential oil deterredD. suzukiifrom fruit in the laboratory, and interplanted aromatic plants reduced crop pest populations in other field studies. Regardless of whether peppermint was untrimmed or periodically trimmed to reduce shading of strawberries and promote release of volatiles,D. suzukiiinfestation was consistently lowest in strawberries adjacent to no peppermint. Interplanted peppermint also reduced strawberry yield in the second year of the experiment. Abundance ofLygus lineolaris(Palisot de Beauvois) (Hemiptera: Miridae), a strawberry pest, was higher in plots with peppermint, but abundances ofLigyrocoris diffusus(Uhler) (Hemiptera: Rhyparochromidae) andNeortholomus scolopax(Say) (Hemiptera: Lygaeidae), seed feeders but not common strawberry pests, were lower in plots with peppermint. Overall, interplanted peppermint is not recommended forD. suzukiimanagement, but other strategies for using volatile, repellent compounds in the field should be investigated.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton in many areas of the southern United States. An experiment was conducted at two locations in Mississippi during 2016 and 2017 to evaluate action thresholds for tarnished plant bug on a novel Bacillus thuringiensis cotton that expresses the Cry51Aa2.834_16 toxin. Treatments included the current action threshold, a 2× threshold, and treatments where insecticides were only applied during the early season (preflower) or only during late season (during flowering) based on the current action thresholds. These were compared to an untreated control and a weekly insecticide use regime that received weekly insecticide sprays. All treatments were imposed on both Bt Cry1Aa2.834_16 cotton and a nontraited cotton. The Bt Cry1Aa2.834_16 trait reduced the number of tarnished plant bugs and injury, and improved yields compared to nontraited cotton. For all spray treatments except the weekly insecticide use regime, yields were greater for the Bt Cry51Aa2.834_16 cotton than the nontraited cotton. In terms of thresholds, Bt Cry1Aa2.834_16 cotton sprayed based on current action thresholds resulted in similar yields to the weekly insecticide use regime of both cotton types. In contrast, the 2× threshold resulted in lower yields than the current threshold for both cotton types. Though thresholds intermediate to the currently recommended action threshold and the 2× threshold were not tested, these data suggest that currently recommended action thresholds appear appropriate for Bt Cry51Aa2.834_16 cotton. These results suggest that this trait will be an important component of current IPM programs in cotton where tarnished plant bug is an important pest.

The available data on seasonal development of plant bugs (Mirinae: Mirini) are reviewed, and the level of understanding of their seasonal adaptations is evaluated. The ecological responses involved in control of seasonal development of 14 species from 5 genera (Adelphocoris, Apolygus, Lygus, Lygocoris, and Stenotus) are analyzed in detail. All the studied species are broadly polyphagous and produce a varying number of annual generations in different climatic zones. The studied members of four genera, namely Adelphocoris, Apolygus, Lygocoris, and Stenotus, hibernate at the embryonic stage while bugs of the genus Lygus do so at the adult stage. Some species of the genera Adelphocoris and Lygus, in particular Lygus pratensis, have acquired a pronounced ability to fly over long distances, facilitating the search for flowering vegetation. However, unlike many insects that make distant migrations in the state of adult diapause, females of plant bugs of the genus Adelphocoris migrate with mature eggs in their oviducts. This feature allows Adelphocoris females to successfully colonize new areas even in the absence of males, since females do not need additional mating in the colonized area. For the majority of Mirini species experimentally studied in the laboratory, the temperature parameters of development and the sum of effective temperatures needed to complete the full generation were calculated. When combined with observations done under natural conditions, these data allowed us to determine the exact number of annual generations produced by the species or population. The role of day length in the control of seasonal development was analyzed in detail in three species of the genus Adelphocoris: A. triannulatus, A. suturalis, and A. lineolatus. The conditions inducing and terminating adult diapause were studied in detail in Lygus hesperus in the southern United States. The seasonal development of Lygocoris pabulinus is an unusual example of an obligate host plant change during the year. The diapausing eggs of this species overwinter in the tissues of woody plants but the nymphs then migrate onto herbaceous plants on which the summer generations develop. Such a seasonal strategy is more characteristic of aphids (Homoptera) than of true bugs (Heteroptera). On the whole, our analysis of the available data indicates that the control of seasonal development of plant bugs of the subfamily Mirinae is still poorly understood despite their high economic importance. Most reports deal with a small number of experimentally studied species and are limited to the data on temperature parameters of development. The important role of photoperiodic adaptations in the control of seasonal development has been demonstrated only for a few well-studied species (e.g., Adelphocoris triannulatus); such data are crucial for analysis and prediction of seasonal development and spread of harmful and beneficial insects, since the seasonal cycle of each population of a given species is strictly synchronized with the local conditions.

Lygus lineolaris is an important native pest of cotton in the mid-southern USA and a potential invasive species in other parts of the world. L. lineolaris feeds on more than 300 plant species, especially preferring reproductive plant organs but also feeding on young terminal leaves. There is little known about feeding behaviors performed on cotton leaves nor of associated injury symptoms triggered. Herein, we used the most accurate way to study feeding of piercing–sucking insects, i.e., electropenetrography (EPG). EPG was used to quantify L. lineolaris feeding behaviors on young terminal leaves of cotton, for third, fourth, and fifth instars plus male adults. Both non-probing (combined walking, standing and antennation) as well as probing behaviors (cell rupturing, transition, and ingestion) were compared with a time course of digitally measured leaf damage. Overall, L. lineolaris, especially adults, spent most time in non-probing behaviors. For probing behaviors, the longest duration was cell rupturing, especially for fourth and fifth instars followed by the third instars. The greatest damage to cotton leaves occurred when high numbers of wound-inducing cell-rupturing probes, which inject macerating saliva, were combined with minimal subsequent ingestion of saliva. On cotton leaves, this style of cell rupturing matches that of older nymphs. Thus, even small amounts of cell rupture feeding and ingestion by older L. lineolaris nymphs are damaging to cotton leaf terminals. These results help to understand the cause of damage to L. lineolaris hosts and consequently aid in developing strategies to reduce crop loss.

Lygus hesperus Knight (Miridae: Hemiptera), a key pest of cotton in the United States, is a highly polyphagous insect. Upland cotton (Gossypium hirsutum L. var. hirsutum) and alfalfa (Medicago sativa L.) are two major field crop hosts of Lygus hesperus in the Texas High Plains. While alfalfa is considered a source of Lygus in cotton, Lygus intercrop movement behavior has not been fully characterized in cotton-alfalfa systems. Understanding the intercrop movement behavior of Lygus may facilitate better decision-making for Lygus management in these crops. A series of studies including a mark-release-recapture study and season-long field monitoring of Lygus were conducted in the Texas High Plains, USA. Season-long field marking and monitoring of Lygus intercrop movement revealed bidirectional Lygus movement and confirmed that Lygus preferred alfalfa over cotton. Net movement of Lygus between cotton and alfalfa was influenced by cotton phenology. A “two-crop/two-marker” field-marking and monitoring approach was successfully applied in characterizing Lygus seasonal intercrop movement. This approach can be used to study the effect of various crop management practices on Lygus intercrop movement and is applicable to other pests and cropping systems.

Simple Summary The tarnished plant bug, Lygus lineolaris, is a polyphagous, sap-feeder that causes significant economic damage in several field crops, especially cotton (Gossypium hirsutum L.) in the mid-southern United States. In 2020, it was reported that 4.8 million acres of cotton were infested by Lygus spp. in the United States. A broad host range, polyphagous feeding behavior and high mobility of this pest along with resistance development to conventional pesticides helped them establish as a significant pest of concern for cotton growers in the mid-south. Since the publication of a review by Layton (2000) on damage caused by Lygus lineolaris, many new research studies have been published on the Lygus biology, ecology, and integrated pest management strategies. A comprehensive review paper that summarizes these latest research developments and Lygus management strategies will be useful for researchers and cotton growers. In this review, we report and discuss the latest developments in Lygus research and the new control strategies that have been developed in the last two decades. Abstract The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), (Hemiptera: Miridae) is considered the most damaging pest of cotton (Gossypium hirsutum L.) in the mid-southern United States, although it is established throughout the United States, southern Canada, and northern Mexico. The introduction of transgenic crops for the control of moths in the Heliothine complex and eradication of the boll weevil, Anthonomus grandis, from much of the United States led to greatly reduced pesticide use in cotton fields, which allowed L. lineolaris to emerge as a new primary pest of cotton in the mid-southern United States. Since the publication of a review by Layton (2000) on damage caused by Lygus lineolaris, many new studies have been published on the changes in host range, population dynamics, sampling methods and thresholds, cultural practices, sex pheromones and attractant blends, novel pesticides and insecticide resistance mechanisms, olfactory and feeding behaviors, introduction of biological control agents, host-plant resistance mechanisms, and new molecular and genetic tools for integrated pest management of Lygus species in cotton and other important crops. Here, we review and discuss the latest developments in L. lineolaris research in the last two decades.

A method for rearing the southern green stinkbug, (Nezara viridula L.) (Heteroptera: Pentatomidae), using a modified lygus semi-solid artificial diet was developed. First to second-instar nymph were reared in a density of 631.5 ± 125.05 eggs per Petri-dish (4 cm deep × 15 cm diam). Second instar to adult were reared in a density of 535.0 ± 112.46 s instar nymphs per rearing cage (43 × 28 × 9 cm). Mating and oviposition occurred in popup rearing cages (30 × 30 cm), each holding 60–90 mixed sex adults of similar age. Adults emerged 35.88 ± 2.13 d after oviposition and survived for an average of 43.09 ± 9.53 d. On average, adults laid 223.95 ± 69.88 eggs in their lifetime, for a total production of 8,099 ± 1,277 fertile eggs/oviposition cage. Egg fertility was 77.93% ± 16.28. Egg masses held in petri-dishes had a total hatchability of 79.38% ± 20.03. Mortality of early nymphs in petri-dishes was 0.64% ± 0.12 for the first instar and 1.37% ± 0.45 for second instar. Late nymphal mortality in rearing cages was 1.41% ± 0.10, 3.47% ± 1.27, and 4.72% ± 1.29 for the third, fourth, and fifth instars, respectively. Survivorship from nymphs to adults was 88.48% ± 2.76. Using artificial diet for rearing N. viridula could reduce cost by avoiding time-consuming issues with daily feeding fresh natural hosts and insect manipulation. It could increase reliability and simplicity of bug production, which should facilitate mass rearing of its biological control agents.

Reduction in pests targeted by Bt cotton is widely studied; however, other phytophages not affected by Bt cotton-expressed toxins are increasing, suggesting these potential pests might occupy ecological niches of primary pests and become new key pests requiring use of broad-spectrum insecticide. During the 2017 spring-summer crop season, insects were collected on 10 genetically modified (GM) hybrids of cotton (Gossypium hirsutum L.), planted at “Rincon del Buitre” ranch, belonging to “Universidad Autonoma Agraria Antonio Narro” (UAAAN) at San Pedro, Coahuila, Mexico. The 13,422 phytophagous insects collected from GM cotton were in five orders: Coleoptera, Diptera, Hemiptera, Lepidoptera, and Thysanoptera; ≈12,766 of the individual insects were in Hemiptera, mainly whiteflies (Aleyrodidae), for a total of 657 other insects collected. Coleoptera were 18.5% of the families, 19.4% of species, and 6.6% of individuals; Diptera had 29.6, 27.8, and 17.2%, respectively; Hemiptera (without Aleyrodidae) had 25.9, 27.8, and 18.9%, respectively; Lepidoptera had 18.5, 19.4, and 44.6%, respectively, and Thysanoptera had 3.7, 2.8, and 2.5%, respectively. Species with more individuals than 5% of the total were Anagasta kuehniella Zeller (32.7%), Spodoptera exigua Hubner (11.0%), Epichlorops sp. Becker (10.7%), Lygus oblineatus Say (9.0%), Diabrotica balteata Leconte (6.9%), Anthonomus grandis Boheman (5.9%), and Bemisia tabaci Gennadius (≈12,766 individuals). Species with greatest incidence among cotton hybrids were Epichlorops sp. (70%), L. oblineatus and D. balteata (each 60%), and A. grandis and Aphis gossypii Glover (each 30%). Monitoring increasing abundance of secondary pests on Bt crops can indicate if the pests threaten sustainable production of the crop.

Lygus bugs are highly polyphagous piercing/sucking insects found throughout North America. Collectively, they have been reported to feed on over 330 plant species (one of the broadest host range ever documented for a group of insects); they also feed on many economically important crops. Despite its prevalence across North America and status as a common pest in many agroecosystems, very little is known about how Lygus bugs regulate their intake of nutrients. In reality, little is known about nutrient regulation for most hemipterans, specifically non-phloem feeding species in the suborder Heteroptera. This likely reflects difficulties in developing adequate artificial diets for insects with piercing/sucking mouthparts. There is, however, an artificial diet for L. hersperus, and in this study we modified it and performed choice and no-choice experiments to determine how L. hesperus regulates its intake of two macronutrients – protein (p) and carbohydrates (c) – that are tightly linked to survival and performance in other insect herbivores. In choice experiments L. hesperus was allowed to select between two foods with different protein:carbohydrate ratios. We documented strong regulation for protein and carbohydrates, with late instar nymphs selecting a slightly protein-biased intake target (protein-carbohydrate ratio = 1.5:1). We also performed no-choice experiments, where nymphs were restricted to a single food. Here, the protein-carbohydrate ratio of their food had a strong impact on survival, which was highest for nymphs reared on the treatment with a protein-carbohydrate ratio closest to the self-selected intake target (determined by the choice experiments), but no significant impact on developmental time or mass gain. Our data are the first of their kind for a non-phloem feeding hemipteran and provide a starting point for more broadly understanding and further investigating the nutritional ecology/physiology of Lygus bugs. Our study also provides a framework for exploring nutrient regulation in other hemipterans and for optimizing artificial diets for piercing/sucking insects, especially heteropterans.

Lygus Hahn (Hemiptera: Miridae) feeding in faba beans (Vicia faba Linnaeus (Fabaceae)) often results in a reduction in seed quality and economic losses. Traditionally, seed damage is assessed subjectively through visual examination by a trained individual, but the use of non-destructive imaging to evaluate seed quality is gaining momentum. The focus of this study was to determine the ability to quantify Lygus species damage in faba bean using shortwave-infrared imaging and two analysis techniques: (1) spectral angle mapper and (2) simple reflectance indices. Seed samples were visually assessed for damage before imaging in 242 wavebands between 980 and 2500 nm. Four spectral intervals, involving 102 wavebands, were identified as optimal for the detection of seed damage using spectral angle mapper. A strong relationship was obtained between the area of seed damage derived using spectral angle mapper and visually (R2 = 0.95). Seed damage derived by thresholding of two normalised faba bean damage indices involving reflectance at 1086 and 1313 nm and 2218 and 2342 nm also showed a strong relationship with the visual assessment (R2 = 0.92). The two image analysis techniques provided similar results. The study suggests that imaging in the shortwave-infrared wavelengths and the derivation of simple indices can effectively quantify faba bean damage by Lygus feeding.

Thrips (Thysanoptera: Thripidae) and tarnished plant bug, Lygus lineolaris (Hemiptera: Miridae), are among the most important insect pests of cotton, Gosssypium hirsutum, in the mid-southern United States. These pests are currently managed primarily by insecticides; however, a new Bt toxin, Cry51Aa2.834_16 is under evaluation for control of thrips and tarnished plant bug. Experiments were conducted to evaluate the behavioral response of thrips and tarnished plant bug to Bt Cry51Aa2.834_16. Adult thrips avoided Bt Cry51Aa2.834_16 cotton in field choice tests and in separate field tests of Bt and non-Bt cotton not treated with insecticides. In a greenhouse choice test, approximately twice as many adult thrips and eggs were found on non-Bt compared with Bt Cry51Aa2.834_16 cotton. Similarly, in a field test of nontreated Bt Cry51Aa2.834_16 and non-Bt cotton, 68% of adult thrips collected were found on non-Bt cotton. In cotton that was not sprayed with insecticides, Bt Cry51Aa2.834_16 did not affect the distribution of tarnished plant bug within the canopy, although more square and flower injury was caused by tarnished plant bug in non-Bt cotton. Adult tarnished plant bug exhibited a nonpreference for diet containing lyophilized Bt Cry51Aa2.834_16 leaves and for excised Bt Cry51Aa2.834_16 squares in choice tests with non-Bt squares. The behavioral responses of these pests when exposed to this new Bt toxin will play a key role in the efficacy and potential resistance management strategies if this new technology is incorporated in an overall cotton insect pest management system.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), causes severe damages in strawberry (Fragaria × ananassa Duchesne ex Rozier; Rosaceae) fields in Québec, Canada. Currently, only chemical insecticides successfully control that major pest. Lygus lineolaris aggregate in trap crops such as buckwheat (Fagopyrum esculentum Moench; Polygonaceae) and white mustard (Sinapis alba Linnaeus; Brassicaceae) but do not remain long enough on these plants to significantly reduce damages on strawberries. However, the attractiveness of the trap crop gives the opportunity to gather L. lineolaris in an area of the field where chemical treatments could be applied more efficiently. The aim of this study was to test the effectiveness of the combination of trap crop (buckwheat and white mustard) and chemical treatments to control L. lineolaris. Randomised complete-block design included treatment with either no trap crop, buckwheat, or white mustard row planted close to strawberry plants. Half blocks were treated with insecticide (cypermethrin) sprayed on strawberry plants (in treatment without trap crop) or directly on trap crop. We found that L. lineolaris was more abundant on buckwheat than on white mustard or strawberry plants. Insecticide application on trap crops reduced the population on these hosts, but did not reduce L. lineolaris on adjacent strawberry plants. Behavioural avoidance and physiological pesticide resistance could explain this result.

Economically damaging infestations of Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), the tarnished plant bug, have been increasing in North Carolina and Virginia cotton since 2009. We conducted experiments to compare prophylactically timed sprays based on cotton phenology and current action thresholds based on sweep net and drop cloth sampling. In the second year of the study, we included planting date as a factor, with early and late-planted cotton. We found L. lineolaris nymph densities were reduced by at least 60% in North Carolina and 74% in Virginia in threshold plots when compared with the untreated control. Protecting the crop from first square through the fourth week of bloom afforded at least 30% control across planting dates in Virginia and at least 40% control in North Carolina. Economic returns were two to three times greater in early-planted cotton than in late-planted cotton. Treating cotton at action threshold or using prophylactic sprays from first square until the sixth week of bloom in early-planted cotton yielded over $500/ha in net returns in both North Carolina and Virginia. This study supports previous research that shows controlling L. lineolaris infestations during squaring and early weeks of flowering is critical for maximizing yield potential. Our findings also suggest that prebloom and bloom thresholds based on adult and nymphal density devised in the Mid-South may need revision in North Carolina and Virginia.

Background Plant bugs (Lygus spp.) and thrips (Thrips spp.) are two of the most economically important insect pest groups impacting cotton production in the USA today, but are not controlled by current transgenic cotton varieties. Thus, seed or foliar-applied chemical insecticides are typically required to protect cotton from these pest groups. Currently, these pests are resistant to several insecticides, resulting in fewer options for economically viable management. Previous publications documented the efficacy of transgenic cotton event MON 88702 against plant bugs and thrips in limited laboratory and field studies. Here, we report results from multi-location and multi-year field studies demonstrating efficacy provided by MON 88702 against various levels of these pests. Results MON 88702 provided a significant reduction in numbers of Lygus nymphs and subsequent yield advantage. MON 88702 also had fewer thrips and minimal injury. The level of control demonstrated by this transgenic trait was significantly better compared with its non-transgenic near-isoline, DP393, receiving insecticides at current commercial rates. Conclusion The level of efficacy demonstrated here suggests that MON 88702, when incorporated into existing IPM programs, could become a valuable additional tool for management of Lygus and thrips in cotton agroecosystems experiencing challenges of resistance to existing chemical control strategies. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Cabbage seedpod weevil (Ceutorhynchus obstrictus Marsham; Coleoptera: Curculionidae) and Lygus Hahn (Hemiptera: Miridae) species are part of the late season insect pest complex of canola (Brassica Linnaeus; Brassicacea) in the southern prairies of Canada. From 2010 to 2013, large strips in 73 commercial fields were studied in southern Alberta to validate action thresholds for cabbage seedpod weevil and assess the impact of insecticide spraying at the early flower stage for cabbage seedpod weevils on abundance of Lygus at the pod stage. Only fields planted in April accumulated the damaging populations of cabbage seedpod weevils, such that the application of an insecticide resulted in significant yield protection. The economic injury level for the cabbage seedpod weevil was calculated at 20 cabbage seedpod weevils per 10 sweeps, but an action threshold of 25–40 is recommended because sampling mainly occurs along the edge where cabbage seedpod weevils are initially concentrated. At the pod stage, Lygus were lower in strips sprayed with insecticides at the early flower stage than in those not sprayed, but the differences were not statistically significant. Furthermore, Lygus were generally below economically damaging levels in early seeded fields. Therefore, there is no benefit of spraying early seeded fields to attempt to prevent Lygus outbreaks when cabbage seedpod weevils are below thresholds because Lygus may pose a risk only in fields planted later in the season.

Cotton (Gossypium hirsutum L.) has nectar containing modified stomates called nectaries that can be located on leaves, bracts or calyces. The nectar attracts some beneficial insects such as bees, but also predatory damaging insects such as heliothines and Lygus species. There is a naturally occurring mutation that eliminates the nectar containing nectaries and makes the cotton plants less attractive to insects. The nectariless (ne) trait is associated with a double recessive mutation of two genes (ne1 and ne2) on homeologous chromosomes 12 and 26. Expression of the trait can be variable and is also affected by environmental conditions. This makes accurately selecting for the trait based on phenotype difficult. This study identified SSR and SNP markers that can be used by breeders for marker assisted selection (MAS) of the nectariless trait. DNA markers associated with the genes conditioning the trait and used for MAS, will allow cotton cultivars to be easily developed that have decreased attractiveness to insects and reduce the need for insecticides, especially those harmful to beneficial insects such as honeybees.