Control potential of Trialeurodes vaporariorum by the autoparasitoid Encarsia gennaroi, a newly recorded wasp in Canadian greenhouses

Abstract: In 2025 a newly recorded Encarsia species was found parasitizing Trialeurodes
vaporariorum in greenhouses in Canada, ON with evidence suggesting it may compete with E. formosa and disrupt ongoing T. vaporariorum control. Individuals were assessed
morphologically and genetically confirming the species as E. gennaroi. Here, we report the
results of initial trials that assess T. vaporariorum control by E. gennaroi alone or in
combination with E. formosa in cup arenas with particular emphasis on whether the species
represents a comparable or better candidate for pest suppression on short-season greenhouse
crops. We observed significant T. vaporariorum suppression in all parasitoid treatments, with suppression being greatest when both parasitoid species were released together. The presence of E. gennaroi in Ontario represents the first record of this species in Canada and brings forth an opportunity for development of a novel inundative biological control agent for T. vaporariorum, providing a new way to mitigate this challenging and persistent pest of
greenhouse crops, especially in year-round production systems.