Tarnished plant bug (TPB) (Lygus lineolaris Palisot de Beauvois; Hemiptera: Miridae), is the number one insect pest in U.S. Mid-South crops including cotton. Development and deployment of lines exhibiting partial resistance to TPB could reduce the quantity of insecticides needed to control this pest. We have evaluated TPB resistance of cotton lines in small plots since 2003. Insecticides were not applied for TPB. When TPB damage was readily seen in flowers of the susceptible check, examination for “dirty flowers” was made on six white flowers per day for 5 to 8 days. Cumulative percent dirty flowers over sampling days was then calculated for each plot. Over the last 21 years, we evaluated 2,724 lines in 102 different tests. Variation between supposed resistant and susceptible check cultivars were relatively consistent over tests. These data were used to quantify the level of TPB resistance in breeding strains and in 90 germplasm lines and cultivars released from the University of Arkansas Cotton Breeding Program, as well as cultivars and breeding lines in the annual Arkansas Cotton Variety Test and Regional Breeders’ Network Test. Over the years, nectariless and highly pubescent lines have consistently provided some TPB resistance. However, TPB resistance has been found in some nectaried and glabrous lines. These findings suggest the existence of different mechanisms for TPB resistance.

Cotton, Gossypium hirsutum (L.), is a vital crop across the southern U.S. Numerous insect species are yield-limiting pests throughout the cotton growing regions of the U.S., often requiring multiple foliar insecticide applications annually. Those insecticides pose an indirect risk to honey bees, Apis mellifera (L.), and other pollinators through contaminated nectar, pollen, or other routes during cotton bloom. Currently, pest managers only consider efficacy against the target pest when selecting insecticides and give little consideration to honey bee toxicity. The objective of this study was to incorporate honey bee acute toxicity data as a non-target insect pollinator and insecticide efficacy data against target pests into insecticide selection. Efficacy trials were conducted in mid-southern U.S. to determine the efficacy of eight and five currently recommended insecticides against tarnished plant bug (Lygus lineolaris [Palisot de Beauvois]) and bollworm (Helicoverpa zea [Boddie]), respectively. Insecticides were ranked based on historical published data for their toxicity to honey bees and efficacy against the targeted pest based on standardized trials across multiple states. The rankings were multiplied to give equal weight to honey bee toxicity and pest efficacy. Novaluron, sulfoxaflor, and flonicamid provided the best balance between efficacy against tarnished plant bug and acute toxicity to honey bees. Chlorantraniliprole provided the best balance between honey bee toxicity and bollworm efficacy. These findings can be used to improve integrated pest management strategies by maximizing control of pests while considering honey bee toxicity.

An insulin-like peptide mediates trehalose storage in the western tarnished plant bug, Lygus hesperus.

Abstract Phytozoophagous insects, whose diets mainly consist of plant resources, can also feed on animal resources. Within populations, individuals' diets may vary according to their food preferences. The environment and their genetics determine these preferences. The degree of prey voracity (zoophagy) is likely to influence the ecological interactions of individuals. In the case of crop pests, these ecological interactions determine their economic impact. This study aimed to measure the genetic variation in the degree of zoophagy of a phytozoophagous pest, the tarnished plant bug Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae). Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were offered, as animal resources, to L. lineolaris individuals from 15 isofemale lines in a laboratory experiment, where individuals from each line did or did not have access to an alternative plant resource. The results indicate that tarnished plant bugs consume a significant quantity of E. kuehniella eggs per day and that this behaviour varies according to the availability of a plant resource. Additionally, the broad‐sense heritability (H2) in zoophagy is significant, with an estimated 0.27. Moreover, highly zoophagous lines are less responsive to the availability of plant resources than lowly zoophagous lines. The results suggest that individuals within tarnished plant bug populations exhibit varying levels of prey consumption, which may indicate potential differences in trophic behaviour. However, the relationship between fitness and prey consumption in this phytozoophagous insect has yet to be established.

Vulnerability Of Hybrid Populus Nursery Stock To Injury By The Tarnished Plant Bug, Lygus Lineolaris (Hemiptera: Miridae)

The tarnished plant bug, Lygus lineolaris (TPB), (Palisot de Beauvois), and the western tarnished plant bug (WTPB), Lygus hesperus, Knight, are major agricultural pests that cause significant damage to a wide range of crops in the southeastern and southwestern United States. Flonicamid (commercial name: Carbine 50WG) is generally effective against various sap-feeding pests, including both L. hesperus and L. lineolaris. This study evaluated the toxicity of flonicamid on third-instar nymphs and adults of both Lygus species under laboratory conditions. Two bioassay methods were used: spray application to assess both contact and oral toxicity, and dipping to evaluate oral toxicity. Results showed that L. hesperus was significantly more susceptible to flonicamid than L. lineolaris across both bioassay methods. While no significant differences in toxicity were observed between spray and dipping assays, third-instar nymphs exhibited significantly higher sensitivity than adults in both species. The addition of piperonyl butoxide (PBO), a known inhibitor of cytochrome P450-monooxygenases (P450s), significantly enhanced the toxicity of flonicamid, suggesting that P450 enzyme plays a critical role in its detoxification. Sublethal exposure to flonicamid also induced increased P450 activity in both species. These findings provide valuable insights into the differences in susceptibility between L. lineolaris and L. hesperus to flonicamid and indicate that P450-mediated detoxification is critical for flonicamid metabolism. Such insights are valuable for early resistance monitoring and optimizing flonicamid application in integrated pest management programs.

In the Mid-South region of the U.S., the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is the most economically damaging insect pest of cotton, Gossypium hirsutum (L.). During 2022 and 2023, tarnished plant bugs accounted for more than 70,000 lost bales of cotton and caused almost $50 million of economic losses in Mississippi per annum. Scouting for tarnished plant bug in cotton prior to bloom is accomplished by direct insect counts using a sweep net and indirect sampling through evaluation of cotton square (flower bud) retention. Cotton consultants across the Mid-South use a variety of square retention monitoring methods. Research was conducted in the Mississippi Delta to evaluate six different square retention monitoring methods compared to whole plant assessment in non-ThryvOn and ThryvOn cotton. Cotton was planted as a split-plot arrangement within a randomized complete block design with insecticide program as the main-plot factor and technology as the subplot factor. Cotton technology and tarnished plant bug control did not affect method of square retention monitoring, whereas sampling interval and the growth stage of cotton did. These data suggest that assessing damage to the third node during the first 2.5 weeks of squaring best reflects whole plant damage. After this time, accessing square damage in the top three nodes or third node only from the terminal until bloom offers the best sampling efficiency while reflecting whole plant damage prior to bloom. These practices could enable scouts to make management decisions in a timely manner to reduce input costs.

A split-split plot experiment was conducted in Stoneville, MS in 2022 and 2023 to establish more precise insect termination timing to reduce insecticide applications for tarnished plant bug during late bloom in cotton. The main-plot factor was cotton technology that included non-ThryvOn and ThryvOn cotton. The subplot factor was removal timing. In each year, manual removal of squares took place during the fourth or fifth week of bloom. The sub-subplot factor was level of square removal consisting of 0, 50, and 100% above the uppermost first position white flower. To understand plant growth, maturity measurements were taken beginning at the first week of bloom until defoliation. These measurements included plant height, total node counts, nodes above white flower, and nodes above cracked boll. Cotton yield was also recorded. Results from 2022 and 2023 showed differences in plant maturity when 100% square removal was done during the fourth week of bloom. Due to differences among varieties, ThryvOn cotton had greater yields than non-ThryvOn cotton. These data combined with previous research suggest that insecticide termination could occur after the fourth week of bloom without significant yield loss.

The tarnished plant bug, Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae), is an economically important pest of row crops worldwide. Ten isolates of entomopathogenic nematodes (EPNs) (Rhabditida: Steinernematidae and Heterorhabditidae) were evaluated against the third instar nymphal stage of the tarnished plant bug and its generalist predator, the sculpted damsel bug, Nabis roseipennis Reuter (Hemiptera: Nabidae), one of the most abundant and commonly encountered damsel bugs in cotton and soybean agroecoscapes across the Southeastern United States. The objectives of these experiments were to assess the infectivity of entomopathogenic nematodes (EPN) by direct topical exposure against the sculpted damsel bug and tarnished plant bug, whether the predator prey choice is affected by EPN infection, and if feeding on EPN-infected tarnished plant bug (TPB) prey items could result in cross-infection of the predator. Mortality rates at a concentration of 200 infective juveniles (IJs)/mL significantly differed among isolates and insect species, ranging from 30% to 93% for tarnished plant bugs and from 6% to 38% for sculpted damsels, respectively. The third instars of L. lineolaris were more susceptible to the ten nematode isolates than N. roseipennis. Higher pathogenicity on the tarnished plant bug and a low mortality potential make strains HbHP88, HbVS, Sc17c+e, and SfSN the most promising candidates for the biological control of L. lineolaris under lab and greenhouse conditions while preserving beneficial predators of the Southeastern United States.

Mirid plant bugs (Hemiptera: Miridae), including Lygus hesperus (western tarnished plant bug), are key pests of numerous agricultural crops. While management of this pest relies heavily on chemical insecticides, the evolution of resistance and environmental concerns underscore the need for new and more effective approaches. Genetic-based strategies that target male fertiliy are currently being evaluated for population suppression. However, a lack of candidate gene targets with appropriate function, specifically in non-model species like L. hesperus, has hindered progress in the development and application of such approaches. Given their conserved role in stabilization of the flagella axoneme and association with sperm motility in many organisms, members of the tektin gene family represent logical targets for genetic-based sterilization. Here, we identified four homologs of the non-vertebrate tektin family from L. hesperus and used RNA interference-mediated knockdown to assess their roles in male fertility. Although transcription of the four tektins was predominantly in the testis, knockdown had negligible effects on either sperm abundance or male fertility. Our results suggest that tektins do not play a critical role in sperm fertilization of eggs in L. hesperus and are thus likely poor targets for genetic-based sterilization approaches in this species.

The polyphagous Lygus hesperus Knight is a serious pest on many crops in the western USA, including California’s central coast. Although L. hesperus adults can cause damage to broccoli and cauliflower, symptoms from their interactions with these plants are not fully characterized. Characterizing the feeding and ovipositional damage will help in the early diagnosis of the problem in the field and in greenhouses. Thus, the objective of this study was to characterize the feeding and ovipositional injury symptoms in broccoli and cauliflower after exposing 0, 1, 3, 5, and 10 adult L. hesperus to seedlings of broccoli and cauliflower for 24 h, 48 h, and 7 d. Although distorted and “blind” shoots were observed, feeding injury did not rapidly manifest into damage after 7 d post-exposure with high counts of adults on broccoli and cauliflower seedlings. The ovipositional injury was expressed as lesions that developed rapidly with a high density of adults in 24 h. The same levels of damage were observed with three or five adults to these hosts in 48 h. Significant positive correlations between the total eggs and lesions developed were observed on broccoli and cauliflower seedlings. After adult L. hesperus exposure, the growth of broccoli seedlings was reduced, but there was no effect on the growth of cauliflower seedlings. For diagnosis, data show that lesions are associated with adult L. hesperus ovipositional activity on these crops, which recommends thorough scouting and immediate application of plant protectants to reduce potential crop loss in greenhouses and in the field.

We examined methods of producing day-neutral strawberries in a north temperate climate using alternatives to standard bare-root propagules and clean cultivation between plant rows. Fragaria ×ananassa ‘Albion’ were planted in plastic-covered raised beds in Ithaca, NY, USA, for each of the 2022 and 2023 growing seasons. Plants were selected from the following four propagule types from different developmental stages: standard bare-root plants set in early May; bare-root plants started in the greenhouse in February and planted in early May; bare-root plants started in the greenhouse in March and planted in early May; and plug plants set in the field in fall (Aug 2021 and Oct 2022) of the previous year. To determine if pollination could be enhanced, each type of plant was grown in plots in the field with one of the following between rows: bare ground; a diverse flowering groundcover; or exclusion netting on hoops over the strawberry plants when they were flowering. Pollinators visiting strawberries were observed weekly and identified to species when possible. Fruits were collected weekly and marketable and unmarketable yields were measured through the harvest season. Fall-planted plugs produced significantly higher marketable yields than those of other propagule types in both years. Bare-root plants set in early May had the lowest yield. Percent marketable yield varied depending on the growing year because of drastically different weather conditions. There was no evidence that flowering groundcover attracted pollinators to the strawberry plants because strawberries had few pollinator visits, regardless of the surrounding vegetation. Exclusion netting had significantly higher percent marketable yield and total yield than the those of other groundcover types despite lower percent fruit set, likely because of the benefits of tarnished plant bug exclusion.

Herbivorous insects utilize olfactory and visual cues to orient on suitable host plants, and such cues can be employed to facilitate insect monitoring. Lygus lineolaris Palisot de Beauvois is a polyphagous pest throughout North America. Monitoring this pest as it moves between crop and non-crop hosts remains challenging, and a lack of effective monitoring tools complicates management of this insect. In this study, we examined the electrophysiological and behavioral responses of L. lineolaris to the volatile emissions of 2 crop hosts: alfalfa and strawberry. Gas chromatography with electroantennographic detection was applied to identify antennally active compounds in headspace extracts of flowering host plants, before responses to individual compounds were examined in the field. Five compounds consistently elicited antennal depolarizations in adults of L. lineolaris and, of these, (±)-linalool increased the capture rate of L. lineolaris females in the field. Subsequent experiments examined the influence of visual cues and stereochemistry on capture rate, revealing that lures containing (±)-linalool and (S)-(+)-linalool significantly increased the capture rate of L. lineolaris females compared with traps baited with (R)-(-)-linalool and controls, indicating that L. lineolaris is attracted to (S)-(+)-linalool. While lures increased capture on red traps, this was not the case for white traps, emphasizing the importance of visual cues in the movements and monitoring of L. lineolaris. This study demonstrates that L. lineolaris is attracted to (S)-(+)-linalool in the field, and that attraction depends on trap color. This knowledge is expected to improve monitoring strategies for L. lineolaris in agricultural systems.

Efficacy and timing of foliar plinazolin to manage tarnished plant bug, 2024

Insecticide tolerance in field populations of western tarnished plant bug (<i>Lygus hesperus</i>) in strawberry, 2024

Insecticide efficacy for tarnished plant bug in cotton, 2024

Insecticide efficacy for control of western tarnished plant bug (<i>Lygus hesperus</i>) in strawberry, 2024

Abstract Arkot 1301 (Reg. no. GP‐1152, PI 706424), Arkot 1308 (Reg. no. GP‐1153, PI 706425), Arkot 1309 (Reg. no. GP‐1154, PI 706426), Arkot 1311 (Reg. no. GP‐1155, PI 706427), and Arkot 1317 (Reg. no. GP‐1156, PI 706428) are conventional cotton ( Gossypium hirsutum L.) germplasm lines released by the Arkansas Agricultural Experiment Station in November 2024. Arkot 1301 was derived from a cross of Arkot 0111 and Arkot 0222. The other four lines were derived from crossing an Arkot line with a line from another public cotton breeding program. Arkot 1309 and Arkot 1311 lines share MD10‐5 as a common parent. The second parent for Arkot 1309 and Arkot 1311 was ‘UA48’ and Arkot 0222, respectively. Arkot 1317 was derived from crossing Arkot 0219 and MD87. Arkot 1308 came from crossing Arkot 0409 with GA2009100, an unreleased breeding line developed by the University of Georgia. Arkot 9111 was in parentage of all lines except Arkot 1309. In replicated field tests at four Arkansas sites over 5 years, the five lines produced equal or more lint yield than UA48 and ‘UA222’. Wide adaptation of the lines was indicated by high lint yields of lines in 2021 regional tests. All four lines displayed high resistance to bacterial blight. Plant (leaf, stem, and bract) trichomes, tarnished plant bug response, and yield component traits varied among the lines but were generally more like UA222 than UA48.

ABSTRACTThe polyphagous tarnished plant bug (TPB), Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), inflicts substantial damage to strawberries and to several other valuable crops, impacting both yield quantity and quality. Effective control strategies are crucial to mitigate these losses. This study aimed to elucidate TPB host preferences and reproductive behaviours under various integrated pest management approaches. Experimental arenas with strawberry plants included treatments involving the predator Nabis americoferus (Carayon) (Hemiptera: Nabidae) and trap crops. In each arena, 30 adult TPBs were exposed to different configurations: (i) three strawberry plants, (ii) three strawberry plants with predators, (iii) one strawberry plant alongside two trap crop plants (buckwheat and canola), and (iv) one strawberry plant with the two trap crops and predators. TPB distribution among the arena, plant species and plant sites (flower, stem and adaxial and abaxial leaves) were monitored over 72 h. One week later, adults were removed and the number of emerged first instar nymphs (L1) was recorded three times postexperiment. The results indicate a preference shift in TPB behaviour influenced by plant diversity and predator presence. TPBs exhibited a reduced presence on strawberries when trap crops were introduced, with canola as a preferred plant. This preference for canola was supported by higher TPB offspring counts. Conversely, buckwheat, although less preferred, contributed to diluting TPB populations across plant species. The introduction of N. americoferus showed dual effects: While reducing TPB oviposition on canola, it increased TPB presence on strawberries, highlighting the importance of nonconsumptive effects (NCEs) of predators in agroecosystems. Nonetheless, the combination of canola as a trap crop and N. americoferus as a predator effectively reduces TPB presence on strawberry flowers, essential for fruit development. This approach shows promise when integrated with other strategies, such as vacuuming and pheromone‐enhanced coloured traps.

Stink bug species emerged as major insect pests of cotton in the mid-southern United States following the eradication of the boll weevil and the introduction of genetically modified Bt cotton for lepidopteran pests. Considering the limited number of chemical classes available for insect control, further insights into other chemistries are necessary to inform management strategies with the overall goal of establishing and maintaining the most cost efficient and efficacious control programs for stink bugs in Alabama. The insect growth regulator, novaluron, has shown control of tarnished plant bugs, but little research has been done on its effect in stink bugs. The objective of our study is to evaluate the effects of novaluron, in a laboratory setting, on adult fecundity, nymphal mortality, and yield and damage in the field. We hypothesized that novaluron would have a direct effect on mortality in nymphs and could decrease fecundity in adult stink bugs. Although the effect on fecundity was counter to our hypothesis, this study shows effective control of nymphs in our model insect, the southern green stink bug, Nezara viridula (Hemiptera: Pentatomidae). Future evaluation of proper timing of novaluron applications could make this a valuable tool for residual control of stink bugs in cotton.