Methyl (E,E,Z)-2,4,6-decatrienoate (1) is the aggregation pheromone of the brown-winged green bug, Plautia stali and is also a pheromone synergist of the brown marmorated stink bug, Halyomorpha halys ...pheromone. A scalable and controllable synthesis of methyl (E,E,Z)-2,4,6-decatrienoate (1) was achieved in 5 steps. The stereoselective formation of the 4E, 6Z conjugated double bond was accomplished by a tandem addition reaction of acrolein with acetylene and the 2E double bond was formed by a Heck reaction. The pheromone was obtained in 99 % stereochemical purity and 40 % overall yield starting from (Z,E)-7-bromo-4,6-heptadienal.
A scalable and controllable synthesis of methyl (E,E,Z)-2,4,6-decatrienoate, the aggregation pheromone component of the brown-winged green bug, Plautia stali, was achieved via Heck reaction strategy. Display omitted
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•Eleven parasitoid species, two new, emerged from H. halys egg masses in woodlands and crops.•Prevalence of parasitoid species emerging from egg masses was mainly habitat ...specific.•Emergence of adults and parasitism per egg mass was highest for Trissolcus edessae.•Peak parasitism (72.3%) in apple at a site in 2017 represented the highest parasitism rate.•Predation reached very high levels in soybean and cotton both years of the study.
The invasive brown marmorated stink bug, Halyomorpha halys, is present in the Piedmont and expanding into the Coastal Plains Regions of the southeastern US. Consequently, this study was conducted to evaluate parasitism and predation of H. halys sentinel egg masses by native parasitoids and predators in woodland habitats and orchard, vineyard, row, and vegetable crops alongside these habitats in Alabama and Georgia in 2017 and 2018. Ten primary parasitoid species, including two new records, and one hyperparasitoid emerged from eggs. Trissolcus japonicus was not detected. Ooencyrtus sp. was the prevalent parasitoid species in vegetables while Telenomus podisi was the predominant species in row crops. Anastatus reduvii, An. mirabilis, Tr. brochymenae, and Tr. euschisti were the prevalent species in woodland and orchard habitats. Trissolcus edessae Fouts occurred primarily in orchards. Trissolcus basalis and Gyron obesum were observed in vegetable habitats. Percentage successful development to adults, sex ratio, and percentage of parasitism per egg mass was highest for Tr. edessae. Predation damage included complete and incomplete chewing, stylet sucking, puncture sucking, and removal of whole eggs from egg masses. Hole and non-stylet sucking damage were discovered. Chewing and piercing-sucking predation constituted the majority of predation in woodlands, plum, blueberry, tomato, pecan, peach, and okra. Mainly chewing predation and egg removal occurred in soybean, cotton, and strawberry. Piercing-sucking predation was common in wine grape and apple. There was no difference between fresh and frozen eggs in the proportion of parasitism and predation both years. In 2017, overall percent parasitism was higher for blueberry compared to other crops except peach and apple. No differences were detected in 2018. Peak parasitism (72.3%) in apple at a site in 2017 represented the highest parasitism rate. Predation was highest in soybean and cotton. Indeed, predation in soybean reached very high levels in 2017 (96.3%) and 2018 (90.3%). In conclusion, native natural enemies parasitize and prey on H. halys egg masses in the southeastern US.
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•Generalist predators were assayed on various stages of Halyomorpha halys in the laboratory.•Predator taxa varied in their consumption of different H. halys life stages.•Chewing ...predators and omnivores most frequently damaged eggs.•Hemipteran predators were the most frequent cause of nymphal mortality.•The importance of nymphal predation to H. halys biocontrol may be underestimated.
Halyomorpha halys (Stål) is an invasive pest of agriculture in the USA. Feeding damage from H. halys affects dozens of crops yet little is known about the community of predators which prey on H. halys in its invaded range. Ten taxa of predatory or omnivorous insects were evaluated for their capacity to consume eggs and nymphs of Halyomorpha halys in laboratory mesocosm experiments. Predators were collected from agricultural ecosystems in New Jersey, starved for 24–48h, and then exposed to H. halys eggs, first instar, or second instar nymphs. Survivorship of control prey in predator-excluding containers within the arenas was compared to that of predator treatment groups to determine the effect of predator presence. Stage-specific differences in H. halys survivorship among life stages were observed for several predator taxa indicating stage-specific predation. Acrididae, Coccinella septempunctata (L.), Podisus maculiventris (Say) (nymphs and adults), and Tettigoniidae reduced the hatch rate of H. halys eggs. Hemipteran predators, including Nabis spp. and Reduviidae, reduced the survivorship of first instar nymphs. Similarly, Nabis spp. and P. maculiventris nymphs reduced the survivorship of second instar nymphs. Acrididae, Nabis spp., P. maculiventris nymphs, Reduviidae, and Tettigoniidae showed stage-specific tendencies in their consumption of H. halys. Morphological similarities between the immature stages of H. halys may facilitate predator suppression of these mobile stages. These results indicate that predation estimates that rely solely on sentinel egg masses may underestimate the impact of generalist predators on other H. halys life stages.
•We investigated the virome associated to an italian population of H. halys.•Seven new viral sequences belonging to different taxonomical groups were reported.•The potential of viruses as biocontrol ...agents has been discussed.
Halyomorpha halys (Stål, 1855) (Hemiptera: Pentatomidae), the brown marmorated stink bug, is an invasive pentatomid native to East-Asia, and introduced worldwide in recent times. It is a polyphagous pest with approximately 300 host plants, which, due to its plasticity, reproductive and feeding behavior, long-distance flight, and walking as well as human-mediated dispersal ability, is able to cause significant economic and ecological damage. In several cases pest control mediated by insecticide treatments leads to unsatisfactory efficacy, mostly due to insect recovery ability. Thus, the most promising method for the long-term management of this pest has been focused with growing emphasis on classical biological control strategies. In this framework, viruses have untill now been poorly investigated in H. halys with only a single virus described from the US territory. For this reason we investigated the virome associated with a small and well described population of H. halys from Piedmont (Italy) describing for the first time 7 new viral sequences belonging to different taxonomical groups. Further studies will be necessary to assess the biological and ecological effects the viruses have on their host. Due to the agricultural importance of this insect, the biological characterization of these viruses would give important information on the possibility to exploit viral entities as biological control agents. Finally, the presence of a such relevant number of viruses from a small population suggests a wide association between the brown marmorated stink bug and viral entities. Further studies to determine the possible exploitation of viral sequences to trace different populations are ongoing.
To improve our understanding of adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) overwintering biology and to better inform models of its population dynamics, its temporal pattern of spring ...emergence was investigated using experimental overwintering shelters in screened cages within protective structures. In 2012, plastic shelters containing 100 adults were deployed in unheated, unlighted buildings, and adjacent woodlots in Virginia, USA. In 2013 and 2014, wooden shelters containing 300 paint‐marked adults were deployed in pairs in six woodlots across Virginia, West Virginia, and Maryland, USA; one in a closed cage and one in a cage with the top removed, enabling emerged adults to be counted or to disperse, respectively. In 2013 and 2014, pheromone‐baited and non‐baited pyramid traps encircled the shelters at each site. Regular counts of adults that emerged into the closed cage and of marked and ‘wild’ (unmarked) adults captured in traps were conducted from February or March through early July. In 2012, emergence patterns from shelters in buildings and woodlots were very similar and matched those recorded from woodlots in 2013 and 2014. In all years, a small peak of emergence occurred in about mid‐April, a larger and more prolonged peak was observed between mid‐May and early June, and emergence ended by early July. Of the 449 H. halys adults captured in traps between 2013 and 2014, only three were marked individuals from shelters in the open cage, suggesting that adults emerging from overwintering sites may require a dispersal flight before responding to pheromone‐baited traps. In 2013 and 2014, respectively, 98 and 93% of captures were in pheromone‐baited traps, but there was no correlation between the weekly number of adults that emerged from shelters in the closed cages and captures in traps.
Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), the brown marmorated stink bug, is an invasive polyphagous insect that can cause serious economic injury to specialty and row crops in the United ...States and globally. To date, H. halys has been managed with repeated insecticide applications. While progress has been made toward development of trap-based monitoring tools to guide management decisions, little is known regarding the trapping area over which a single pheromone-baited trap captures H. halys. We conducted single trap, multiple distance mark-release-recapture experiments; results were used to estimate trapping area for nymphs and adults in sites without host plants present (open field) and for adults in sites with host plants present (apple orchard). Plume reach for pheromone-baited sticky traps was consistently estimated to be <3 m. Maximum dispersive distance in an open field devoid of host plants was estimated to be 40 m for nymphs and 120–130 m for adults resulting in trapping areas of 0.58 ha and 4.83–5.56 ha, respectively. When traps were deployed in association with host plants within the border row of an apple orchard, adult maximum dispersive distance and trapping area was reduced to 70 m and 1.67 ha, respectively. These results indicate that the behavioral response of H. halys to pheromonal stimuli is influenced by the presence of host plants and that trapping area for pheromone-baited traps will likely change relative to the cropping system in which it is deployed. Caution should be taken when extrapolating these results, because the measured values may differ in other crop systems.
Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive species that has become an important orchard pest in the Mid-Atlantic region of the US. Adults and nymphs feed on tree fruit. Feeding ...injury from adults has been characterized but the injury from nymphs has not been examined systematically. Since the four plant-feeding instars of H. halys (second through fifth) differ substantially in size, it is plausible that the effects of their feeding on fruit injury and injury expression may differ among them. We compared feeding injury at harvest from young nymphs (second plus third instars), older nymphs (fourth plus fifth instars), and adults that were caged on ‘Smoothee Golden’ apples and ‘Redhaven’ peaches in early June (peach and apple), late July (peach), and late August (apple). Individual apples and peaches were caged at fruit set and assigned to the following treatments (n = 28/treatment): 1) control (no H. halys), 2) young nymphs or 3) adults early in the season, and 4) young nymphs, 5) older nymphs or 6) adults later in the season. Fruit in each treatment were exposed to 3–4 young nymphs, two older nymphs or 1–2 adults placed in the cages for 96 h and evaluated for external and internal feeding injury within 36 h after harvest. No injury was recorded from unexposed peaches or apples. The percentage of injured fruit and number of injuries per fruit varied significantly among the exposed treatments. Early season feeding by young nymphs yielded the least injury to peaches and apples. In apples, the highest percentage of injured fruit and number of injuries per fruit were caused by late season feeding by adults. In peaches, early season adult feeding produced the highest percentage of injured fruit and injuries per fruit. More internal than external injury was recorded on peach and no such difference was observed on apple. The implications of these findings on H. halys management in fruit orchards are discussed.
•Feeding by Halyomorpha halys nymphs caused injury to apple and peach.•Nymphal injury differed between old and young nymphs.•Early-season feeding by nymphs yielded the least injury to apples and peaches.•Late-season feeding by adults injured apple fruit the most.•Early-season feeding of adults caused more injury on peaches.
The brown marmorated stink bug, Halyomorpha halys (Stål), is a highly polyphagous species native to Asia that has become a serious invasive agricultural and nuisance pest across North America and ...Europe. Classical biological control host range evaluations have revealed egg parasitoid Trissolcus japonicus (Ashmead) to be the primary candidate biocontrol agent for field release against H. halys. However, these evaluations only provide us with the physiological host range of T. japonicus. Other Trissolcus species have demonstrated that contact kairomones from different host species elicit varied responses in the parasitoids' host foraging behaviors. To assess T. japonicus response to host kairomones, mated naive females were exposed to leaf surfaces contaminated with adult kairomones from its preferred host, H. halys, or from a native nontarget host, Podisus maculiventris (Say) (Heteroptera: Pentatomidae). Red maple, apple, and soybean were used as plant substrate treatments. The wasp's residence time on the leaf surface, linear walking velocity, and angular walking velocity were observed and measured using Noldus EthoVision XT tracking software. Within each leaf treatment, T. japonicus displayed stronger behavioral responses on leaves contaminated with contact kairomones from H. halys. The parasitoid resided on H. halys contaminated leaves for approximately twice as a long as it did on P. maculiventris contaminated leaves. Further, both species' kairomones elicited significant decreases in parasitoid walking velocity on all tested substrate types. Overall, our study suggests that kairomone-based behavioral studies can be used to further evaluate the host specificity of T. japonicus and can be an invaluable supplement to classical biocontrol host range testing regimes.
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