Comparison of Spathius agrili vs. Spathius galinae Host Seeking Abilities in the Context of Agrilus planipennis Control
Date
2024-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Spathius agrili Yang (Braconidae) and Spathius galinae Belokobylskij (Braconidae)
are two larval parasitoid wasps used in biological control to manage emerald ash borer
populations, Agrilus planipennis Fairmaire (Buprestidae), (hereafter EAB) because of
the invasive insect’s harmful impact on ash trees across the United States and Canada.
According to recent studies, S. galinae has had better success in establishing across
northern climates in which EAB is most commonly detected. This study is meant to
investigate olfactory cues and host selection behavior to potentially determine
additional factors that explain why one species has been more successful than the
other. Olfactometer assays were conducted with both species in competitive and non competitive settings. Choice decisions and average run times were recorded and
compared between wasps. When given olfactory cues emitted by the host complex, S.
agrili was more likely to make a choice within the time limit and was quicker on
average than S. galinae in making several host selection decisions in both competition
environments. While these traits do not explain S. galinae establishment success, they
reaffirm that the parasitoid’s success is due to temperature tolerance and host
synchronization rather than behavior.