Response of a parasitoid wasp to a bittering agent

Authors: MUYIZERE, MEREVILLE - Northern Illinois University; GUNATHUNGA, PANCHALIE - Northern Illinois University; Geden, Christopher - Chris; KING, BETHIA - Northern Illinois University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: House flies are a great nuisance to humans and can transmit pathogens to both humans and livestock. Populations of house flies are controlled through manure management, as well as chemical control measures (e.g., pesticides, toxic fly baits), and/or biological control measures, such as use of parasitoid wasps. However, use of toxic sugar baits can also harm non-targeted arthropods. Some toxic baits have a bittering agent aside from their active ingredient, which is used to prevent accidental ingestion by non-targeted organisms. An example of such bittering agent is denatonium benzoate, commercially known as “Bitrex”. Bitrex is used at a concentration of 100 ppm in several toxic baits for house flies. Insect responses to Bitrex varies by species and by the concentration present in the baits. In this study, the response of the house fly parasitoid, Spalangia cameroni, to Bitrex was examined. The parasitoids showed no aversion responses to Bitrex at doses up to 200 ppm. The results indicate that fly parasitoids are at risk for being killed when they encounter commercial toxic sugar baits that are commonly used for fly control.

Technical Abstract: House flies are a great nuisance to humans and can transmit pathogens to both humans and livestock. Populations of house flies are controlled through manure management, as well as chemical control measures (e.g., pesticides, toxic fly baits), and/or biological control measures, such as use of parasitoid wasps. However, use of toxic sugar baits can also harm non-targeted arthropods. Some toxic baits have a bittering agent aside from their active ingredient, which is used to prevent accidental ingestion by non-targeted organisms. An example of such bittering agent is denatonium benzoate, commercially known as “Bitrex”. Bitrex is used at a concentration of 100 ppm in several toxic baits for house flies. Insect responses to Bitrex varies by species and by the concentration present in the baits. In this study, the response of the house fly parasitoid, Spalangia cameroni, to Bitrex was examined. The parasitoids showed no aversion responses to Bitrex at doses up to 200 ppm. The results indicate that fly parasitoids are at risk for being killed when they encounter commercial toxic sugar baits that are commonly used for fly control.