RESUMO
Brown marmorated stink bug (Halyomorpha halys Stål) is an invasive and economically important agricultural and ornamental insect pest now established in 46 U.S. states. It was first detected in Utah in 2012 and began causing agricultural damage in 2017. Tart cherry (Prunus cerasus Linnaeus) is a major processed agricultural commodity in Utah; yet, its susceptibility to brown marmorated stink bug is unstudied. Limb cages with six brown marmorated stink bug adults, nymphs, or no brown marmorated stink bug were established in a randomized complete block design in a tart cherry orchard to determine feeding impact on different fruit developmental stages. After 1 wk of feeding, half of the fruits in each cage were removed to assess feeding intensity, and the remainder left through maturity to assess marketability and quality. Feeding by adults and nymphs between petal fall and fruit pit hardening, even at feeding pressures as low as 1.7-4.0 feeding sites per fruit, caused 100% abscission of fruits, significantly reducing marketability when compared with the control treatment. For fruits that escaped abscission and matured, few quality differences were detected among treatments, indicating that brown marmorated stink bug feeding caused minimal detectable quality loss to this processed tree fruit crop. We conclude that tart cherries are at risk of abscission with short-term brown marmorated stink bug feeding between petal fall and pit hardening when overwintered adults or F1 nymphs are present in orchards, and suggest that longer-term feeding may be necessary to cause quality and yield reductions after pit hardening.
Assuntos
Heterópteros , Prunus avium , Rosaceae , Rosales , Animais , Frutas , UtahRESUMO
The highly polyphagous and invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), has become a significant insect pest in North America since its detection in 1996. It was first documented in northern Utah in 2012 and reports of urban nuisance problems and plant damage have since increased. Biological control is the preferred solution to managing H. halys in North America and other invaded regions due to its alignment with integrated pest management and sustainable practices. Native and non-native biological control agents, namely parasitoid wasps, have been assessed for efficacy. Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is an effective egg parasitoid of H. halys in its native range of southeast Asia and has recently been documented parasitising H. halys eggs in North America and Europe. Field surveys for native and exotic egg parasitoids using wild (in situ) and lab-reared H. halys egg masses were conducted in suburban and agricultural sites in northern Utah from June to September 2017-2019. Seven native wasp species in the families Eupelmidae and Scelionidae were discovered guarding H. halys eggs and adult wasps from five of these species completed emergence. Native species had low mean rates of adult emergence from wild (0.5-3.7%) and lab-reared (0-0.4%) egg masses. In 2019, an adventive population of T. japonicus was discovered for the first time in Utah, emerging from 21 of the 106 wild H. halys egg masses found that year, and none from lab-reared eggs. All T. japonicus emerged from egg masses collected on Catalpa speciosa (Warder). Our results support other studies that have observed biological control of H. halys from T. japonicus and improved parasitoid wasp detection with wild as compared to lab-reared H. halys egg masses.