| Summary: | The brown stink bug, Euchistus servus (Say), is a polyphagous pest of multiple
cultivated hosts in Virginia. It recently emerged as a potentially devastating pest of
maize, Zea mays L. (Poaceae), in eastern Virginia where small grain (e.g., wheat, rye)
production is common. In order to develop an integrated pest management (IPM)
plan, research is needed to determine if brown stink bug feeding causes economic
damage in maize at different growth stages and levels of infestations. Experiments
were conducted in 2018 and 2019 to determine: 1) effectiveness of seed applied and
in-furrow chemical control methods, 2) infestation levels in seedling and
reproductive growth stages that cause economic damage, and 3) the effect, if any, of
E. servus feeding on grain quality and mycotoxin contamination. Results of these
experiments demonstrated that infestation levels (i.e., number of bugs divided by
number of plants) of 11% and 15% in seedling and late vegetative maize,
respectively, can cause measurable yield reduction at harvest. Seedling damage
from E. servus is significantly mitigated by neonicotinoid seed treatments which are
applied to nearly all commercial maize seed. Further, experiments indicated that
maize quality can be affected by E. servus feeding in late reproductive stages of
development. Results of these experiments will help to inform Virginia maize
producers of the need to manage E. servus throughout the growing season. === Master of Science in Life Sciences === The brown stink bug, Euschistus servus, has emerged as a potential economic
pest of maize (commonly referred to as "corn" or "field corn") in Virginia following
reduced broad-spectrum insecticide use and increased adoption of no-tillage or
reduced-tillage crop production systems. Stink bug infestations in maize frequently
occur at two times in the growing season: following cover crop termination and
following small grain harvest. We need to determine the effects of brown stink bug
infestations on maize yield and quality, as well as the effectiveness of chemical
management options, to help minimize yield losses and input costs for maize
producers in our region. Experiments were conducted to determine: 1) the control
provided by insecticidal seed treatments and in-furrow insecticide applications, 2)
the level of brown stink bug infestations that cause economic damage at different
growth stages of maize, and 3) the effect of brown stink bug feeding and a Fusarium
fungal pathogen on grain yield and quality. Results of these experiments determined
economic injury levels in seedling corn and late vegetative stages. Additionally, we
found that universally applied neonicotinoid seed treatments mitigated early
damage. Further, stink bug feeding through reproductive stages of development can
reduce grain quality. Our results will help Virginia maize producers to make
informed pest management decisions throughout the season.
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