Adjacent Habitat Influence on Stink Bug (Hemiptera: Pentatomidae) Densities and the Associated Damage at Field Corn and Soybean Edges

The local dispersal of polyphagous, mobile insects within agricultural systems impacts pest management. In the mid-Atlantic region of the United States, stink bugs, especially the invasive Halyomorpha halys (Stål 1855), contribute to economic losses across a range of cropping systems. Here, we characterized the density of stink bugs along the field edges of field corn and soybean at different study sites. Specifically, we examined the influence of adjacent managed and natural habitats on the density of stink bugs in corn and soybean fields at different distances along transects from the field edge. We also quantified damage to corn grain, and to soybean pods and seeds, and measured yield in relation to the observed stink bug densities at different distances from field edge. Highest density of stink bugs was limited to the edge of both corn and soybean fields. Fields adjacent to wooded, crop and building habitats harbored higher densities of stink bugs than those adjacent to open habitats. Damage to corn kernels and to soybean pods and seeds increased with stink bug density in plots and was highest at the field edges. Stink bug density was also negatively associated with yield per plant in soybean. The spatial pattern of stink bugs in both corn and soybeans, with significant edge effects, suggests the use of pest management strategies for crop placement in the landscape, as well as spatially targeted pest suppression within fields.     

Influence of corn on stink bugs (Heteroptera: Pentatomidae) in subsequent crops

In southeastern United States farmscapes, corn, Zea mays L., is often closely associated with peanut, (Arachis hypogaea L.), cotton, (Gossypium hirsutum L.), or both. The objective of this 3-yr on-farm study was to examine the influence of corn on stink bugs (Heteroptera: Pentatomidae), Nezara viridula (L.), and Euschistus servus (Say), in subsequent crops in these farmscapes. Adults of both stink bug species entered corn first, and seasonal occurrence of stink bug eggs, nymphs, and adults indicated that corn was a suitable host plant for adult survival and nymphal development to adults. Stink bug females generally oviposited on cotton or peanut near the interface, or common boundary, of the farmscape before senescence of corn, availability of a new food, or both. Adult stink bugs dispersed from crop to crop at the interface of a farmscape in response to senescence of corn, availability of new food, or both. In corn-cotton farmscapes, adult stink bugs dispersed from senescing corn into cotton to feed on bolls (fruit). In corn-peanut farmscapes, adult stink bugs dispersed from senescing corn into peanut, which apparently played a role in nymphal development in these farmscapes. In the corn-cotton-peanut farmscape, stink bug nymphs and adults dispersed from peanut into cotton in response to newly available food, not senescence of peanut. Stink bug dispersal into cotton resulted in severe boll damage. In conclusion, N. viridula and E. servus are generalist feeders that exhibit edge-mediated dispersal from corn into subsequent adjacent crops in corn-cotton, corn-peanut, and corn-peanut-cotton farmscapes to take advantage of suitable resources available in time and space for oviposition, nymphal development, and adult survival. Management strategies for crops in this region need to be designed to break the cycle of stink bug production, dispersal, and expansion by exploiting their edge-mediated movement and host plant preferences.     

Seeding Dates and Cultivars Effects on Stink Bugs Population and Damage on Common Bean <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L

Fields experiments were conducted during two growing seasons (2010–2011 and 2012–2013) at three seeding dates to identify stink bug (Hemiptera: Pentatomidae) species and to determine their seasonal population density fluctuation and damage caused to three common bean (Phaseolus vulgaris L.) cultivars “Ica Pijao,” “Cubacueto 25–9,” and “Chévere.” Stink bug species observed were Nezara viridula (L.), Piezodorus guildinii (Westwood), Chinavia rolstoni (Rolston), Chinavia marginatum (Palisot de Beauvois), and Euschistus sp. The most prevalent species was N. viridula in both seasons. The largest number of stink bugs was found in beans seeded at the first (mid September) and third (beginning of January) seeding dates. Population peaked at BBCH 75 with 1.75, 0.43, and 1.25 stink bugs/10 plants in 2010–2011 and with 2.67, 0.45, and 1.3 stink bugs/10 plants in 2012–2013 in the fields seeded the first, second, and third seeding dates, respectively. The lowest numbers of stink bugs were found in beans seeded at the second (mid November) seeding date. A significant negative correlation between relative humidity and number of stink bugs was found in 2010–2011, and a similar tendency was observed in 2012–2013. The highest seed and pod damage levels occurred in cv. “Chévere” and the lowest in cv. “ICA Pijao” during both seasons. Results suggest that cv. “ICA Pijao” and the second (mid November) seeding date is the best choice to reduce stink bug damage.     

Impact of brown stink bug (Heteroptera: Pentatomidae) feeding on corn grain yield components and quality

Brown stink bug, Euschistus servus (Say) (Heteroptera: Pentatomidae), damage on developing corn, Zea mays L., ears was examined in 2005 and 2006 by using eight parameters related to its yield and kernel quality. Stink bug infestations were initiated when the corn plants were at tasseling (VT), mid-silking (R1), and blister (R2) stages by using zero, three, and six in 2005 or zero, one, two, and four bugs per ear in 2006, and maintained for 9 d. The percentage of discolored kernels was affected by stink bug number in both years, but not always affected by plant growth stage. The growth stage effect on the percentage of discolored kernels was significant in 2006, but not in 2005. The percentage of aborted kernels was affected by both stink bug number and plant growth stage in 2005 but not in 2006. Kernel weight was significantly reduced when three E. sercus adults were confined on a corn ear at stage VT or R1 for 9 d in 2005, whereas one or two adults per ear resulted in no kernel weight loss, but four E. servus adults did cause significant kernel weight loss at stage VT in 2006. Stink bug feeding injury at stage R2 did not affect kernel damage, ear weight or grain weight in either year. The infestation duration (9 or 18 d) was positively correlated to the percentage of discolored kernels but did not affect kernel or ear weight. Based on the regression equations between the kernel weight and stink bug number, the gain threshold or economic injury level should be 0.5 bugs per ear for 9 d at stage VT and less for stage R1. This information will be useful in developing management guidelines for stink bugs in field corn during ear formation and early grain filling stages.     

Influence of non‐crop plants on stink bug (Hemiptera: Pentatomidae) and natural enemy abundance in tomatoes

We investigated the effects of weed hosts on stink bug density and damage (Euschistus conspersus Uhler and Thyanta pallidovirens Stal), and a nectar bearing plant on natural enemies of stink bugs in the Sacramento Valley of California. Stink bug density and fruit damage were evaluated in processing tomatoes adjacent to weedy and cultivated borders. The density of E. conspersus was significantly greater in tomatoes adjacent to weedy borders in July but not during August/September. Thyanta pallidovirens was less abundant overall (19%), but was found in significantly greater densities adjacent to cultivated borders in July but not in August/September. Mean percent fruit damage by stink bugs was greater adjacent to the weedy border than the cultivated border, but this difference was not significant. Stink bug egg parasitism and generalist predator density were evaluated in fresh market tomatoes adjacent to a sweet alyssum (Lobularia maritima L.) border and an unplanted control border at three sites. Egg parasitism was significantly greater in the alyssum treatment for the 9–12 September sampling period. Jalysus wickhami VanDuzee (Hemiptera: Berytidae) density was significantly greater in the alyssum treatment in mid‐June. No other significant differences in predator populations were detected. Results of these two studies show that habitat manipulations have the potential to reduce densities of E. conspersus in tomato, the first step in developing a farmscape management plan for stink bug control.     

Attractiveness of conspecific stink bugs to adult stink bug-baited traps in soybean fields

The attractiveness of live adult stink bugs used as baits in traps in soybean fields, Milyang, Korea, to conspecific stink bugs was evaluated. Both sexes of bean bug, Riptortus pedestris Fabricius (Hemiptera: Alididae), and one-banded stink bug, Piezodorus hybneri Gmelin (Hemiptera: Pentatomidae), were attracted to conspecific male adults-baited traps. Likewise, both sexes of brown-marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), and sole bug, Dolycoris baccarum L. (Hemiptera: Pentatomidae), were attracted to traps baited with conspecific male stink bugs. However, in Nezara antennata Scott (Hemiptera: Pentatomidae), both male and female used as baits in traps were attractive to conspecific adults. Accordingly, these results suggest that the only male adults of H. halys and D. baccarum and both sexes of N. antennata are attractive to conspecific male stink bugs.     

Stink Bug Feeding Induces Fluorescence in Developing Cotton Bolls

Background

Stink bugs (Hemiptera: Pentatomidae) comprise a critically important insect pest complex affecting 12 major crops worldwide including cotton. In the US, stink bug damage to developing cotton bolls causes boll abscission, lint staining, reduced fiber quality, and reduced yields with estimated losses ranging from 10 to 60 million dollars annually. Unfortunately, scouting for stink bug damage in the field is laborious and excessively time consuming. To improve scouting accuracy and efficiency, we investigated fluorescence changes in cotton boll tissues as a result of stink bug feeding.

Results

Fluorescent imaging under long-wave ultraviolet light showed that stink bug-damaged lint, the inner carpal wall, and the outside of the boll emitted strong blue-green fluorescence in a circular region near the puncture wound, whereas undamaged tissue emissions occurred at different wavelengths; the much weaker emission of undamaged tissue was dominated by chlorophyll fluorescence. We further characterized the optimum emission and excitation spectra to distinguish between stink bug damaged bolls from undamaged bolls.

Conclusions

The observed characteristic fluorescence peaks associated with stink bug damage give rise to a fluorescence-based method to rapidly distinguish between undamaged and stink bug damaged cotton bolls. Based on the fluorescent fingerprint, we envision a fluorescence reflectance imaging or a fluorescence ratiometric device to assist pest management professionals with rapidly determining the extent of stink bug damage in a cotton field.     

Gripping ease in southern green stink bugs Nezara viridula L. (Heteroptera: Pentatomidae): Coping with geometry,orientation and surface wettability of substrate

The southern green stink bug Nezara viridula L. (Heteroptera, Pentatomidae) is highly polyphagous, preferring apically situated seeds and fruits on more than 150 plant species belonging to over 30 plant families all over the world. This forces them to move over highly variable terrains, including plant stems, leaves, pods and buds, which requires efficient attachment. Stink bugs have long slender legs and feet (tarsi) equipped with paired curved claws, paired soft adhesive pads (pulvilli), and flattened lanceolate hairs (setae), which arise ventrally on the first and second foot segments (tarsomeres). To characterize their attachment abilities on well‐defined test substrates, here we comparatively measured and analyzed the traction forces of bugs walking horizontally and vertically on hydrophilic (water attractive) and hydrophobic (water repellent) glass plates and rods. The latter correspond to the geometry of preferred feeding sites of stink bugs in the field. The results show a clear contribution of tarsal flattened lanceolate hairs to the stink bug's attachment. Higher traction forces are generated on a glass rod than on a glass plate, corresponding to up to individual maximum of 43 times the stink bug's body weight. Substrate hydrophobicity promotes the attachment, while the measured forces are up to eight times lower when tarsal hairs are disabled. The combination of smooth and hairy tarsal pads results in a remarkable attachment ability, which enables N. viridula to climb unstable apical plant parts, and supports their invasive behavior and global dispersion.     

Electropenetrography (EPG): a Breakthrough Tool Unveiling Stink Bug (Pentatomidae) Feeding on Plants

In this article, we review and discuss the potential use of EPG (electropenetrography) as a powerful tool to unveil the feeding process of phytophagous stink bugs (pentatomids). These bugs are relatively big and vigorous, which presents a problem during wiring (i.e., attachment of the gold wire on the bug’s pronotum) for use in EPG. Once this challenge was overcome, using the sand paper-and-wire technique, several species have been studied using EPG, yielding waveforms that, coupled with histological studies, revealed the ingestion sites on different host plants. These sites include vascular tissues (xylem and phloem), parenchyma tissue, and seed endosperm. Stink bugs usually feed by secreting a gelling saliva to create a salivary sheath that surrounds the stylets and anchors/supports/lubricates them. However, using the cell rupture feeding strategy and the tactic of combined laceration (mechanical movements of the stylets) and maceration (action of chemical enzymes) breaks the plant cells enabling ingestion. The number of ingestion events and their duration is variable according to the feeding site. Waveforms generated have typical patterns according to the feeding site. Recent studies with several species of stink bugs have started to demonstrate the potential of EPG as a tool to unveil their feeding behavior. This may also be useful in the applied field of stink bug management, such as the development and screening of resistant genotypes and the action of chemical insecticides affecting their feeding and survivorship.     

Dynamics and seasonal abundance of stink bugs (Heteroptera: Pentatomidae) in a cotton-soybean ecosystem

Two soybean varieties (early-maturing group V and late-maturing group VII) and two cotton varieties (conventional and transgenic (Bt) were grown in adjacent replicated large field plots (approximately 0.1 ha each) at two locations for 3 yr. The dynamics and relative abundance of phytophagous stink bugs within these two crops were observed. The most abundant pentatomid species in both crops for all 3 yr were Nezara viridula (L.), Acrosternum hilare (Say), and Euschistus servus (Say). Several other species also were commonly collected. This is the first record of Mormidea lugens (F.) on soybean and E. quadrator Rolston, E. obscurus (Palisot), Holcostethus limbolarius (St?l), and Oebalus pugnax (F.) on cotton. Stink bugs began arriving in soybean when plant growth stages ranged from pod formation to full seed development. Peak numbers of these insects were found in soybean from the time of full-size seeds in the pods until early maturity. The bugs were first attracted to the earlier maturing cultivar (group V), where they remained until plants began to mature (R7). The pentatomids then moved to the later-maturing cultivar (group VII) as it reached full pod to full seed. Stink bugs began arriving in cotton from the time of the earliest flowers until after the first bolls formed. Peak numbers in cotton occurred during the time when all stages of developing bolls were present. Stink bug numbers were much greater in soybean than in cotton over all three seasons. This preference for soybean over cotton indicates the potential use of soybean as a trap crop for attracting stink bugs away from cotton. Additionally, the coordinated use of early- and late-maturing soybean cultivars as a trap crop could minimize the area requiring insecticides, as well as the number of insecticide applications to cotton.     

Attraction of stink bugs to rocket traps with different combinations of wing and landing board color

The stink bugs, Halyomorpha halys and Riptortus pedestris, are two of the most economically important pests of leguminous crops and fruits in Korea. Here we present the results from a field monitoring test that evaluated the effect of variation in rocket trap type and color on stink bugs captures. We tested various types of rocket traps, along with wing combinations and landing boards of various colors. The test was run in soybean fields in Miryang, Korea. We developed a modified rocket trap intended to enhance the capture efficacy of stink bugs. We evaluated traps including (1) yellow rocket trap with a solar fan and blue LED lamp, (2) a yellow trap with solar fan but no light, (3) rocket traps with black, green, yellow, white, red, brown, and blue color stimuli, (4) different color combinations of trap wings, and (5) traps with a landing board were evaluated. Our results showed that yellow winged rocket traps with solar fans and blue LED lamps attracted significantly more stink bug species than other traps, in both soybean fields. Use of these improved traps such as a yellow trap with a solar fan and blue LED lamp, and a yellow trap with a solar fan would therefore enhance the monitoring and capture of stink bugs in diversified agro-ecological landscapes. The potential use of traps with a specific hue, combination of features, and modifications to monitor stink bugs accurately is discussed. Continuing improvements to traps to meet the demands of a changing pest landscape and agricultural mechanization are needed.     

Toxicity of insecticides in a glass-vial bioassay to adult brown, green, and southern green stink bugs (Heteroptera: Pentatomidae)

Adult brown, Euschistus servus (Say); green, Acrosternum hilare (Say); and southern green, Nezara viridula (L.), stink bugs were collected from soybean, Glycine max (L.) Merr., in fall 2001 and 2002 near Stoneville, MS, and Eudora, AR. A glass-vial bioassay was used to determine LC50 values for the three species of stink bugs for the pyrethroids bifenthrin, cypermethrin, cyfluthrin, lambda-cyhalothrin, and permethrin, and the organophosphates acephate, dicrotophos, malathion, and methyl parathion. Results confirmed findings of other researchers that the brown stink bug was less susceptible to pyrethroid and organophosphate insecticides than were green and southern green stink bugs. The susceptibility of all three stink bug species to the insecticides tested was very similar at both test locations. The study established baseline insecticide mortality data from two locations in the mid-South for three stink bug species that are pests of soybean and cotton, Gossypium spp. Data from the tests are valuable for future use in studies on resistance and in resistance monitoring programs.     

Assessing stink bug resistance in soybean breeding lines containing genes from germplasm IAC-100

Sixty-five soybean, Glycine max (L.) Merr., breeding lines containing the stink bug resistant 'IAC-100' in their pedigrees were evaluated for their resistance to stink bug, primarily southern green stink bug, Nezara viridula L., feeding in replicated field trials from 2001 to 2005. Plots were sampled throughout the season for stink bug abundance, and, at harvest, seed samples were rated for stink bug-induced kernel damage. Individual seeds were categorized as having none, light, moderate, or heavy damage plus 100-seed wt and plot yields were determined. Both ground cloth and sweep net sampling procedures were used to compare stink bug densities between the soybean entries. Stink bug densities varied between years; however, in the years when populations exceeded four per row-meter or six per 25 sweeps, there were more damaged soybean seeds (>25%) in the entries with higher stink bug numbers. During the first 2 yr of evaluations, the mean stink bug-damaged soybean seeds ranged from 10.0 to 38.2%. From these differential responses, 28 entries were selected for continued study in 2003-2004. In 2003, stink bug-damaged soybean seeds were low, with damage ranging from 2.9 to 18.2%. In 2004, stink bug damage ranged from 8.8 to 53.2%. From these 28 lines, 12 entries were selected for an advanced field screening trial in 2005, including the IAC-100 and 'Hutcheson'. Damaged soybean seeds ranged from 18.5 to 54.1% among these 12 entries in 2005, under heavy stink bug pressure. From these evaluations, four breeding lines with either Hutcheson X IAC-100 or IAC-100 x 'V71-370' in their genealogy were identified as possible breeding material for future soybean stink bug resistance cultivar development.     

荔枝蝽取食行为的研究

在越冬前和产卵期,荔枝蝽Tessaratoma papillosa Drury在寄主植物-荔枝树的花枝、嫩枝和老枝上都有取食行为。但在这两个不同时期, 其取食行为有显著差异。在越冬前,只有50%～70%的成虫在各类枝条上取食;而处于产卵期的荔枝蝽成虫,在各类枝条上,100%积极取食,且其取食前时间显著短于越冬前在同类枝条上的取食前时间。同一时期在不同枝叶上,荔枝蝽的取食行为也有显著差异。被置于嫩枝叶和花枝上的成虫取食前时间明显短于被置于老枝叶上者;在有选择的情况下,两个时期的成虫都明显地选择在花枝和嫩枝上取食。经分析测定：在不同生长时期,荔枝树的花枝和嫩枝的含水量与含氮量均较老枝叶中的高,可溶性糖含量的变化较大;组织结构也存在明显差异。     

Treatment thresholds for stink bugs (Hemiptera: Pentatomidae) in cotton

The green stink bug, Acrosternum hilare (Say), the southern green stink bug, Nezara viridula (L), and the brown stink bug, Euschistus servus (Say), were predominant phytophagous Pentatomidae detected during 1995-1997 in cotton in South Carolina. These species occurred in similar numbers in conventional and transgenic cotton 'NuCOTN33B', containing the gene for expression of CryIA(c) delta-endotoxin of Bacillus thuringiensis Berliner variety kurstaki. Adult stink bugs moved into cotton from wild and cultivated alternate hosts during July, and reproducing populations usually were detected in cotton from late July into September. Applications of either methyl parathion (0.56 kg [AI]/ha) directed for stink bugs or lambda-cyhalothrin (0.037 kg [AI]/ha) or cyfluthrin (0.056 kg [AI]/ha) for control of cotton bollworm, Helicoverpa zea (Boddie), provided effective control of pentatomids in NuCOTN33B or conventional 'DP5415' and increased yields compared with untreated plots. Fiber quality did not differ among treated or untreated plots of NuCOTN33B. The ground-cloth technique was used to estimate populations of stink bugs, and data indicated that treatment at one bug per 2 m of row adequately protected cotton from yield loss due to stink bug damage. Observations on boll damage indicated that treatment might be necessary if >20-25% reveal internal symptoms of feeding injury during mid- to late season. More detailed damage thresholds should be developed to complement an approach based on population monitoring. This study validated current recommendations for management of pentatomids in cotton, demonstrated the necessity of threshold use for stink bugs in transgenic cultivars expressing endotoxin from B. thuringiensis, and provided insight into further development of management options for pentatomids in the crop.     

Delayed maturity associated with southern green stink bug (Heteroptera: Pentatomidae) injury at various soybean phenological stages

Delayed maturity in soybean, Glycine max (L.) Merr., occurred in response to infestation by southern green stink bug, Nezara viridula (L.), in 4 yr of field studies. Maturity delays followed stink bug infestation that occurred only during the pod set and filling stages (R3-R5.5), and infestations at R3-4 and R5 resulted in delayed maturity more consistently than did infestation at R5.5. Infestation levels of six stink bugs per 0.3 m of row for 7-14 d generally were required to delay soybean maturity. The greatest impact on seed yield and quality parameters followed stink bug infestations that occurred during R3-R5.5, which corresponded closely with the periods of infestation that resulted in delayed maturity. If both delayed maturity and yield reduction are considered, the pod elongation through late pod filling stages were most critical for protecting soybeans from southern green stink bugs.     

Composition and abundance of stink bugs (Heteroptera: Pentatomidae) in corn

The species composition and abundance of stink bugs (Heteroptera: Pentatomidae) in corn, Zea mays L., was determined in this on-farm study in Georgia. Seven species of phytophagous stink bugs were found on corn with the predominant species being Nezara viridula (L.) and Euschistus servus (Say). All developmental stages of these two pests were found, indicating they were developing on the corn crop. The remaining five species, Oebalus pugnax pugnax (F.), Euschistus quadrator (Rolston), Euschistus tristigmus (Say), Euschistus ictericus (L.), and Acrosternum hilare (Say), were found in relatively low numbers. Adult N. viridula were parasitized by the tachinid parasitoid Trichopoda pennipes (F.). There was a pronounced edge effect in distribution of stink bugs in corn. Population dynamics of N. viridula and E. servus were different on early and late-planted corn. Oviposition by females of both stink bug species occurred in mid-to-late-May and again mid-to-late-June in corn, regardless of planting date. In early planted fields, if stink bug females oviposited on corn in mid-July, the resulting nymphs did not survive to the adult stage in corn because ears were close to physiological maturity and leaves were senescing. Density of stink bug adults in early planted corn was relatively low throughout the growing season. In late-planted corn, females of both stink bug species consistently laid eggs in mid-to-late-July on corn with developing ears. This habitat favored continued nymph development, and the resulting adult population reached high levels. These results indicate that corn management practices play a key role in the ecology of stink bugs in corn agroecosystems and provide information for designing management strategies to suppress stink bugs in farmscapes with corn.     

Stink bug rostrum length vs. stylet penetration potential

Stink bugs (Hemiptera: Pentatomidae) and related species continue to plague cotton, Gossypium hirsutum L. (Malvaceae), worldwide. Stink bugs utilize their stylets (housed within the rostrum) to feed upon cotton bolls and transmit pathogens that cause seed and boll rot of cotton. Stylet penetration potential of stink bugs is influenced by species and recent observations indicated a phenomenon whereby stink bugs with shorter rostra yielded deeper stylet penetration estimates. The objective of this study was to elucidate the relationship between rostrum length and known stylet penetration estimates for two pairs of similar‐sized pentatomid species: Chinavia hilaris (Say) vs. Euschistus servus (Say), and Oebalus pugnax (Fabricius) vs. Piezodorus guildinii Westwood. For each species, individual rostral segments were measured to yield total lengths, and measurements were compared against known stylet penetration estimates. Chinavia hilaris and P. guildinii have longer rostra than E. servus and O. pugnax, respectively, yet E. servus and O. pugnax yielded deeper stylet penetration estimates. Deeper stylet penetration by species with shorter rostra can be attributed to differences in the lengths of rostral segments 1 and 2. Euschistus servus and O. pugnax each had significantly longer rostral segments 1 and 2 than C. hilaris and P. guildinii, respectively. Also, the cumulative lengths of rostral segments 1 and 2 comprised a higher overall proportion of the entire rostrum length in E. servus and O. pugnax vs. C. hilaris and P. guildinii, respectively. Rostral segments 1 and 2 are instrumental in the feeding mechanics of these phytophagous species; it is clear that their greater length and their role in stylet penetration model calculations – including the lengths of segments 3 and 4 – override the presumption that total rostrum length equates to stylet penetration potential. This novel finding contributes to the general knowledge of stink bug feeding mechanics.     

Field attraction of the stink bug Euschistus conspersus (Hemiptera: Pentatomidae) to synthetic pheromone-baited host plants.

The attraction of the stink bug Euschistus conspersus Uhler to sources of the synthetic pheromone component methyl (2E,4Z)-decadienoate was investigated in a series of field experiments in native vegetation surrounding commercial apple orchards in Washington. In experiments with pheromone lures placed inside two different tube-type traps, stink bugs were attracted to the immediate area around traps in large numbers, but very few were caught in the traps. Pheromone lures attached directly to the host plant mullein, Verbascum thapsus L., demonstrated that these 'baited" plants attracted significantly more E. conspersus than unbaited plants. Spring (reproductive) and summer (reproductively diapausing) E. conspersus adults, both males and females, were attracted to pheromone-baited plants. There was no significant difference in the number of male or female E. conspersus attracted to pheromone-baited traps or plants in any of the experiments, further characterizing methyl (2E,4Z)-decadienoate as an aggregation, and not a sex pheromone. Stink bug aggregations formed within 24-48 h of lure placement on mullein plants and remained constant until the lure was removed after which aggregations declined over 3-4 d to the level of unbaited plants. The implications of these studies for E. conspersus monitoring and management are discussed.