Do buckwheat insectary strips improve dispersal into orchards and parasitism performance of Trissolcus japonicus?

Monday, November 14, 2022

11:06 AM – 11:18 AM PT

Location: Vancouver Convention Centre, Meeting Room 215/216

Presenting Author(s)

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Emma O. Waltman

PhD Student
Rutgers, The State University of New Jersey
Bridgeton, New Jersey

Co-Author(s)

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Anne Nielsen

Associate Extension Specialist
Rutgers, The State University of New Jersey
Bridgeton, New Jersey

Halyomorpha halys (brown marmorated stink bug, BMSB) is an invasive pentatomid that is a major pest in the United States. In the mid-Atlantic, it first reached outbreak levels in 2010 and has caused severe damage to tree fruit and other crops since. Insecticide-based strategies are the primary management tactic for BMSB, and in outbreak years, applications of broad-spectrum insecticides increase as much as fourfold. Our research aims to decrease reliance on broad-spectrum insecticides by improving biological control of the pest with Trissolcus japonicus (TJ), a parasitoid wasp with BMSB as its primary host that has been found in 15 US states. Where both species are native in Asia, parasitism of BMSB by TJ reaches 80%, but it remains low at < 2 in US orchards, possibly due to a resource-poor agroecosystem.

We conducted field studies in 2021 and 2022. We released TJ into buckwheat strips adjacent to peach orchards and, on the opposite side of the orchard, into mowed grass. We measured parasitism rates of BMSB sentinel eggs in the orchard across from the buckwheat and across from the mowed grass control. Additionally, we measured dispersal by recapturing TJ on yellow sticky cards and used protein-marking to determine if recaptured TJ foraged on buckwheat. Our hypothesis is that the TJ released into buckwheat parasitize a higher proportion of eggs and disperse farther into the orchard compared to TJ released into grass.