Comparison of Yellow and Blue Sticky Cards for Detection and Monitoring Parasitoid Wasps of the InvasiveHalyomorpha halys(Hemiptera: Pentatomidae)

Abstract

The invasive Halyomorpha halys (Stål) is a significant agricultural and urban nuisance pest in many parts of the world. In North America, biological control of H. halys by parasitoid wasps in the families Scelionidae and Eupelmidae has shown promise. An effective technique for detection and monitoring native and exotic parasitoids is the deployment of yellow sticky cards; however, yellow cards also attract nontarget arthropods, reducing efficiency and accuracy of parasitoid screening. This study sought to identify an alternative yet effective trapping technique by comparing the number of target parasitoid wasps [Anastatus spp. Motschulsky (Hymenoptera: Eupelmidae), Telenomus spp. Haliday (Hymenoptera: Scelionidae), and Trissolcus spp. Ashmead (Hymenoptera: Scelionidae)] and arthropod bycatch on yellow and blue sticky cards deployed in urban, orchard, and vegetable landscapes in northern Utah from late May to early October in 2019 and 2020. Yellow sticky cards captured 54–72% more target parasitoids than blue cards from June through August in all three landscape types in both years; however, a positive correlation in parasitoid capture indicated blue cards detect target parasitoids, just in fewer numbers. Both card colors detected adventive Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) in initial findings of 2019, and in expanded locations of 2020. Furthermore, blue cards captured 31–48% less Diptera and nontarget Hymenoptera than yellow cards in both years across all three landscapes, translating to reduced card processing time and impacts to beneficial insect populations. Our results suggest that blue vs yellow sticky cards offer an alternative monitoring technique to survey for H. halys parasitoids.

Habitat and vertical stratification affect capture of stink bugs (Hemiptera: Pentatomidae) and biological control of the invasive brown marmorated stink bug

“…An adventive population of Tr. japonicus , a parasitoid of H. halys in its native range, has also been confirmed in several US states (Talamas et al 2015a, Holthouse et al 2021, Peterson et al 2021, Dyer et al 2022). Prevalence of parasitoid species emerging from stink bug eggs can be habitat specific.…”

Adapting to changing methodology in a long-term experiment

“…Aside from Orthoptera, which are herbivores (Joern 1979) commonly captured on these traps, we selected these taxa because they are important beneficial insects either providing biocontrol (Chalcidoidea, Ichneumonoidea, Syrphidae) or pollination services (Lepidoptera, Syrphidae) (Bonet 2009;Herrmann, Buchholz, and Theodorou 2023;Skevington et al 2019). Given that these taxa are very commonly captured and known to be sensitive to environmental conditions (Benthall et al 2022;Eckberg et al 2015;Holthouse, Spears, and Alston 2021;Toennisson, Klein, and Burrack 2019), they provided an additional, more sensitive test beyond that which would be provided by simply examining the core taxa monitored at the site. Indeed, capture rates of four of the five additional taxa revealed a statistical difference between card types: the new cards appeared to be more attractive to Chalcid wasps, hoverflies, and Orthoptera, but less attractive to Ichneumon wasps.…”

Colored sticky traps for monitoring phytophagous thrips (Thysanoptera) in mango agroecosystems, and their impact on beneficial insects

“…Green, orange, and yellow traps caught the higher numbers of natural enemies, whereas the blue, purple, and white had a lesser effect. Yellow sticky traps are known to trap high numbers of natural enemies of Diptera and Hymenoptera [ 75 ]. An evaluation of sticky traps for monitoring thrips in a cowpea crop, found that beneficial insects were caught 1.7 times more on yellow than on blue traps [ 20 ].…”