Location: Horticultural Crops Disease and Pest Management Research Unit
Title: Flourishing with sugars - following the fate of parasitoids in the fieldAuthor
Submitted to: Current Opinion in Insect Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/21/2023 Publication Date: 1/4/2024 Citation: Lee, J.C. 2024. Flourishing with sugars - following the fate of parasitoids in the field. Current Opinion in Insect Science. 61. Article 101158. https://doi.org/10.1016/j.cois.2023.101158. DOI: https://doi.org/10.1016/j.cois.2023.101158 Interpretive Summary: Flowers, plants bearing extrafloral nectaries (EFN) or sugar sprays have been added to agroecosystems with the expectation that parasitic wasps will feed on it, and will attack more pests. This paper reviews our current understanding of how to monitor wasps for feeding, health status, abundance and reproduction and how the presence of sugar sources influence these factors and ultimately impact suppression of target plant pests by parasitic wasps. Technical Abstract: Habitat manipulation is touted to provide parasitoids with needed sugar sources. As flowers, plants bearing extrafloral nectaries (EFN) or sugar sprays are added to agroecosystems, parsasitoids are expected to feed and lead to improved biological control according to the “Parasitoid nectar provision hypothesis”. This paper reviews studies where sugar-feeding of field-collected parasitoids was monitored via biochemical assays mentioning parameters to indicate recent feeding or honeydew versus nectar feeding. Also, the paper follows subsequent trends in parasitoid abundance, energetic reserves, longevity and per capita fecundity. Starved parasitoids readily feed on sugar sources in the field, and more individuals will feed near sugar sources when sugar is limited in the system. When sugar is not limited, like with honeydew present, trends are not as clear. Some studies follow the hypothesis with improved fecundity and parasitism, while other studies show inconsistent trends between parasitoid feeding, abundance, longevity and parasitism, with some factors improved but not others. Future research could address the dispersal or resting behavior of wasps following feeding since it can influence eventual biological control. Researchers should also consider sampling methods since they may overestimate feeding based on sampling bias. |