Persistence of mating suppression of the Indian meal moth Plodia interpunctella following direct and indirect exposure to commercial mating disruption dispensers

Authors: WIJAYARATNE, LEANAGE K. W. - Rajarata University Of Sri Lanka; Burks, Charles - Chuck

Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2020
Publication Date: 10/14/2020
Citation: Wijayaratne, L., Burks, C.S. 2020. Persistence of mating suppression of the Indian meal moth Plodia interpunctella following direct and indirect exposure to commercial mating disruption dispensers. Journal of Pest Science. 11(10):701. https://doi.org/10.3390/insects11100701.
DOI: https://doi.org/10.3390/insects11100701

Interpretive Summary: The Indian meal moth is a global pest of stored products that is controlled by commercial mating disruption products using passive release to emit high concentrations (relative to females or monitoring lures) of the principal component of the female sex pheromone, thereby preventing males from finding females and females from mating and producing damaging offspring. Since this moth is sexually active throughout the night, an assay system was developed to determine the importance of direct interaction of the male with the dispenser, and whether exposure to mating disruption early in the night is enough to suppress mating throughout the night. Exposure to mating disruption dispensers in the mating assay chamber for the first two hours of a 10-hour night significantly reduced mating when females were introduced four hours later. Trials using only previously-treated assay chambers and other trials using only pre-treated males without exposure in the assay chambers indicate that both direct exposure of males to mating disruption dispensers and indirect effects such as re-emission contributed to mating suppression. These findings will help research and development scientists and practitioners improve mating disruption products and their use, thereby increasing use of this minimally toxic technique for control of pests of many value-added food products worth billions of dollars.

Technical Abstract: The Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is controlled by commercial mating disruption products using passive release to emit high concentrations (relative to females or monitoring lures) of its principal sex pheromone component, (Z9,E11)-tetradecadienyl acetate. Since P. interpunctella is sexually active throughout the scotophase, an assay system was developed to determine the importance of direct interaction of the male with the dispenser, and whether exposure to mating disruption early in the night is sufficient to suppress mating throughout the night. Exposure to mating disruption dispensers in the mating assay chamber for the first two hours of a 10-hour scotophase significantly reduced mating when females were introduced four hours later. Mating was also reduced to a lesser degree in a dose-dependent manner based solely on re-emission of pheromone. Exposure of males to mating disruption dispensers outside the mating assay chamber also significantly reduced subsequent mating in the chambers. These results indicate that the commercial mating disruption dispensers can suppress mating throughout the night base on interaction with the dispenser early in the night. Desensitization resulting from attraction to a high-concentration pheromone source is likely important to this suppression, but other factors such as re-emission from the environment may also have a role. These observations suggest that effectiveness of the mating disruption dispenser might be augmented by using them in conjunction with another formulation such as an aerosol or microencapsulated product.