Abstract
The polyphagous pest, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), damages fruit in orchards and field crops and is often found within nearby woodlands. Pheromone-baited traps can be ...used to monitor H. halys. However, the efficiency of trapping H. halys may vary depending on trapping strategy (live vs. dead capture), location (ground or canopy), and diel periodicity of captures. We compared H. halys capture within fruiting hosts for: (i) live and kill traps on the ground vs. traps in the canopy of black cherry (Prunus serotina Ehrh.) (Rosales: Rosaceae), sugarberry (Celtis laevigata Willdenow) (Rosales: Cannabaceae), and pecan (Carya illinoinensis (Wangenh.) K. Koch) (Fagales: Juglandaceae) trees, (ii) ground and canopy-live traps in sassafras (Sassafras albidum (Nutt.) Nees) (Laurales: Lauraceae), and (iii) whether diel periodicity was detected for live capture in sassafras and cotton. More H. halys adults and nymphs were captured in kill traps than in live traps. More nymphs were captured in kill traps in black cherry and sugarberry on the ground than in the canopy. Live adult capture was significantly greater in sassafras and pecan canopies than on the ground. In cotton and sassafras, more live adults were captured from 8 PM—noon, with the fewest captured from noon—6 PM. A better understanding of stink bug activity in the field allows for improved trapping and, possibly, improved timing of treatment applications.
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•We evaluated whether prey-, predator-, or plant-associated stimuli increase mortality of H. halys egg masses.•The H. halys aggregation pheromone was not used as a kairomone by ...natural enemies.•Presence of methyl salicylate and varying host species did not impact egg mortality.•Other predator attractants did not increase predation damage to egg masses.•We documented Trissolcus japonicus for the first time in West Virginia, USA.
Escape from the natural enemy community by invasive species in their introduced range is a key determinant to their success. Historically in North America, there have been only low levels of predation and parasitism for Halyomorpha halys (Stål), the brown marmorated stink bug. In our study, we sought to determine whether prey-, predator-, or plant-associated stimuli increase mortality of H. halys egg masses, and whether the exotic parasitoid Trissolcus japonicus (Ashmead) is present in West Virginia or New Jersey. We deployed sentinel egg masses over two years in a variety of studies. We found that the H. halys aggregation pheromone was not used as a kairomone by natural enemies, the presence of methyl salicylate and varying host species stimuli did not impact egg mortality, and other predator attractants did not increase predation damage to egg masses. However, we documented Trissolcus japonicus for the first time in Jefferson Co., West Virginia, USA. Ultimately, our study suggests that other related stimuli and potential landscape factors should be investigated for increasing the impact of the natural community on H. halys.
We report the first detection of
Trissolcusjaponicus
, an exotic Asian egg parasitoid and the primary candidate for classical biological control of the invasive brown marmorated stink bug,
...Halyomorphahalys
, in Canada. Twenty-eight
Trissolcusjaponicus
emerged from an
H.halys
egg mass from a site heavily infested by
H.halys
in Chilliwack, British Columbia, in 2018. This egg mass was deployed and retrieved as part of ongoing sentinel egg mass surveys for natural enemies of
H.halys
from 2017–2018 in coastal and interior British Columbia (total of 1,496 egg clusters at 16 sites). The identification of
T.japonicus
was based on biology (high levels of successful emergence from
H.halys
eggs), morphology, and mitochondrial DNA sequences.
Trissolcusjaponicus
was not detected at any other survey sites in 2017–2018; however, three species of indigenous egg parasitoids were found attending or emerging from
H.halys
egg masses at low levels (<4%) at several sites. The origin of the detected
T.japonicus
, the extent of its establishment in British Columbia, and its ultimate impact on
H.halys
populations remain to be determined. Nonetheless, the detection of this exotic biological control agent in Canada concurrently with regulatory review of its intentional importation and release is emblematic of the current uncertainty around regulatory control on the movement of biological control agents across borders.
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•Trissolcus japonicus and T. mitsukurii are valid potential biological control agents of H. halys.•Interspecific competition among BCAs can affect pest control ...success.•Multiparasitism caused a lower reproductive potential offspring production and wasted searching time.
The invasive stink bug Halyomorpha halys, native to east Asia, is a severe agricultural pest of worldwide importance and biocontrol is a promising method for its long-term management. The two Asian egg parasitoids Trissolcus japonicus and Trissolcus mitsukurii are considered to be effective candidates as biological control agents. These species can co-occur in the same habitats and interspecific competition for hosts could therefore have an important role in natural control. We assessed the foraging behavior and the progeny production of both species under laboratory conditions with three different interspecific competition scenarios. With indirect competition, H. halys egg masses previously parasitized by the female of one species were offered to the competitor females after 0, 3, 5, or 7 days. With direct extrinsic competition, females of each species were tested in arenas either when introduced simultaneously (synchronous release) or when half of the host egg mass had already been parasitized by the other species (asynchronous release). Both Trissolcus species were able to parasitize host eggs already parasitized by the other species, although the progeny production always favored the species that arrived first on the host egg mass. However, in the synchronous releases scenario, T. mitsukurii displayed more aggressive behavior and spent more time defending the host egg mass than T. japonicus, resulting in a higher progeny production. Our results showed that multiparasitism among T. japonicus and T. mitsukurii, at least under laboratory conditions, resulted in a general waste of searching time, energy, eggs laid, and a lower reproductive potential by the second-arriving species on the host egg mass.
The invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a mobile, polyphagous agricultural pest that feeds on a variety of plants. In orchard systems, seasonal ...monitoring of adults and nymphs in fruit and nut trees and noncrop host plants in surrounding habitat can be used to identify, in time and space, areas of high-density aggregations to develop targeted pest management strategies. We explored the spatiotemporal distribution of H. halys adults and nymphs and assessed whether seasonal distribution patterns varied according to habitat. From 2018 to 2021, pheromone-baited traps were placed in orchard and noncrop plants to first document the establishment of H. halys at this site and to describe seasonal development. In addition, stink bugs were monitored weekly during 2019–2020 across a grid of baited traps placed within the orchard ecosystem. Based on grid data, we used Spatial Analysis by Distance Indices (SADIE) to identify significant clusters of H. halys and visualized aggregations with interpolated maps. Overall, the distribution of H. halys adults and nymphs were similar; both aggregated primarily in peach and adjacent woodlands followed by pecan. Timing of aggregations was consistent across years and reached the highest levels in July and August. Moreover, we document that H. halys is an established pest within this orchard ecosystem, and that noncrop host plants likely play an important role in maintaining populations of H. halys. To manage H. halys in southeastern orchard systems, growers may need to account for host plants in habitats that surround fruiting trees.
This paper explores the utilization of innovative technologies such as RGB cameras, drones, and computer vision algorithms, for monitoring pests in orchards, with a specific focus on detecting the ...Halyomorpha halys (HH), commonly known as the “brown marmorated stink bug”. The integration of drones and machine learning (ML) into integrated pest management shows promising potential for effectively combating HH infestations. However, challenges arise from relying on vision models solely trained using high-quality images from public datasets. To address this issue, we create an ad hoc dataset of on-site images mainly captured with the help of a drone as well as other devices. We initially conduct an in-depth analysis of the captured images, considering factors such as blurriness and brightness, to possibly improve the performance of the ML algorithms. Afterwards, we undertake the training and evaluation of diverse ML models using distinct approaches within the YOLO framework. We employ a range of metrics to compare their performance and ultimately achieve a satisfactory outcome. Through the optimization of ML models and the correction of image imperfections, we contribute to advancing automated decision-making processes in pest insect monitoring and management, specifically in HH monitoring.
•Drones and AI algorithms enhance orchard Halyomorpha halys (HH) pest monitoring.•Improved dataset of in-field images enhances preliminary results in pest detection.•In-depth analysis of image factors improves ML algorithm performance.•Optimized ML models advance automated decision-making in HH monitoring.
The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive agricultural and nuisance pest that has established across much of the United States and caused ...significant crop losses in the Mid-Atlantic region. While it has been monitored extensively using ground-deployed pheromone traps, the vertical distribution of its life stages in the canopy of wild tree hosts has not been examined. In Virginia, small pyramid traps baited with ‘low-dose’ H. halys pheromone lures were deployed via a pulley system at the lower, mid-, and upper canopy of female tree of heaven (Ailanthus altissima (Mill.) Swingle) in 2016 and 2017 and male A. altissima and hackberry (Celtis occidentalis L.) in 2017. Weekly captures of adults and nymphs were recorded throughout each season. Each year, additional female A. altissima trees were felled during the two main periods of H. halys oviposition. The number and relative locations of all pentatomid egg masses found on foliage were recorded and any parasitoids that emerged from them were identified. Halyomorpha halys adults and nymphs were captured in greatest numbers in upper canopy traps and in lowest numbers in traps near the tree base. More H. halys egg masses were collected from mid-canopy than from the lower or upper canopy. The adventive egg parasitoid, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), emerged most frequently from egg masses found at mid-canopy and was not recovered from those in the lower canopy. Results are discussed in relation to the foraging ecology of H. halys and its natural enemies, including TT. japonicus.
The effect of exposing apples to brown marmorated stink bug, Halyomorpha halys, for discrete intervals before harvest and of post-harvest cold storage on feeding injury expression was evaluated in ...2011 and 2012. Individual apples from four cultivars in experimental orchards in Virginia and West Virginia, USA were caged soon after fruit set to protect them from insect injury. During each of the four weeks preceding harvest of each cultivar, five adult H. halys were placed in a subset of cages for 7-days, then removed. Control fruit were not exposed. The proportion of injured fruit and the number of external injuries was evaluated at harvest, after which the fruit were held in cold storage for about 5 weeks, followed by assessments of the proportion of fruit injured and the number of external and internal injuries. Most exposure timings resulted in external injury at harvest, but fruit exposed closer to harvest tended to show less injury than those exposed earlier. Fruit from all cultivars showed external injury at harvest, with variation in the proportion of injured fruit among them. The proportion of injured fruit and the number of external injuries tended to increase during post-harvest cold storage in some, but not all cultivars. The number of external injuries at harvest and after cold storage underrepresented the number of internal injuries. Results are discussed in the relation to the length of pre-harvest protection required to mitigate fruit injury from H. halys.
•Pre-harvest feeding on apple by Halyomorpha halys caused external injury at harvest.•Feeding during the fourth and third weeks before harvest caused most injury.•In some cultivars, external injury increased during post-harvest cold storage.•Internal injury was often greater than external injury after cold storage.
Egg clutches of many animals hatch synchronously due to parental control 1, 2 or environmental stimulation 3, 4. In contrast, in some animals, embryos actively synchronize their hatching timing with ...their siblings to facilitate adaptive behavior in sibling groups, such as mass migration 5, 6. These embryos require synchronization cues that are detectable from eggs and indicative of when the siblings hatch, such as pre-hatching vocalizations in birds and crocodiles 7, 8. Previous studies, using methods including artificial presentation of non-specific mechanical stimuli, demonstrated that vibrations or other mechanical forces caused by sibling movements are cues used by some turtles and insects 9–13. However, there is no evidence about which movements of tiny embryos or hatchlings, among multiple possibilities, can generate mechanical cues actually detectable through eggs. Here, we show that embryos of the brown marmorated stink bug, Halyomorpha halys, synchronize hatching by responding to single pulsed vibrations generated when siblings crack open their eggshells. An egg-cracking vibration seems to be transmitted to distant eggs within a clutch while still maintaining its function as a cue, thus leading to the highly synchronized hatching pattern previously reported 14. In this species, it is possible that embryos attempt to hatch with short lags after earlier-hatched siblings to avoid egg cannibalism by them 14. The present study illustrates the diversity of social-information use by animal embryos for success in the sibling group.
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•During the hatching of a stink bug, egg cracking generates a single pulsed vibration•Fully developed embryos immediately start hatching when receiving the vibration•The vibration widely spreads across a clutch and induces its explosive hatching•Synchronized hatching crucial for survival is achieved using the vibration as a cue
Diverse animal embryos achieve synchronized hatching within a clutch mainly for mass migration, but social cues used for this purpose are often unclear. Endo et al. show that in a stink bug, a single pulsed vibration generated when an embryo cracks open its eggshell serves as a cue for later-hatching siblings to synchronize hatching.
Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is a highly polyphagous invasive species and an important pest of orchard crops in the United States. In the Mid-Atlantic region, wild hosts of H. ...halys are common in woodlands that often border orchards, and H. halys movement from them into orchards poses ongoing management issues. To improve our understanding of host plant effects on H. halys populations at the orchard–woodland interface, nymphal survivorship, developmental duration, and adult fitness (size and fresh weight) on apple (Malus domestica Borkh.), peach (Prunus persica (L.) Batsch), Tree of Heaven (Ailanthus altissima (Mill.) Swingle), and northern catalpa (Catalpa speciosa (Warder)) were examined in laboratory studies. Specifically, we investigated nymphal performance on the foliage and fruiting structures of those hosts and on single- versus mixed-host diets, as well as the effects of host phenology on their suitability. Nymphal performance was poor on a diet of foliage alone, regardless of host. When fruiting structures were combined with foliage, peach was highly suitable for nymphal development and survivorship, whereas apple, Tree of Heaven, and catalpa were less so, although nymphal survival on Tree of Heaven was much greater later in the season than earlier. Mixed-host diets yielded increased nymphal survivorship and decreased developmental duration compared with diets of suboptimal single hosts. Adult size and weight were generally greater when they developed from nymphs reared on mixed diets. The implications of our results to the dispersal behavior, establishment, and management of H. halys are discussed.
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