New Year IFB Seminar (9th)

Pest control by sterilization and evolution of polyandry: Evolution of Resistant Females or Emergence of Promiscuous Females?

Professor Takahisa Miyatake (Okayama University)

Date and time: January 7, 2025, 16:30-18:00

Location: Conference Room, Institute of Freshwater Biology, Nagano University, 1088 Komaki, Ueda, Nagano

Registration URL: https://docs.google.com/forms/d/e/1FAIpQLSc2yWQxAk7x-LNy8JyP96SA2YNQPER6niIEn2gsGPO2ubSbtA/viewform?usp=dialog

Abstract: Invasive alien insects that cause severe damage to agricultural crops and are designated by the Plant Protection Act are called special pests. The sterile insect release method (=sterilization method) was started in 1971 to eradicate the special pest melon fly. 100 million sterile fruit flies were sprayed from helicopters every week, and in 1993, melon flies were finally eradicated from Japan. Just before eradication, data were published suggesting the appearance of females (resistant females) that could distinguish sterile males in some areas of Okinawa Island (Hibino and Iwahashi 1989, 1991), but the national and prefectural governments thoroughly sprayed huge amounts of sterile insects in areas where wild insects remained, completely eradicating them. As a result, one question remained: Did females evolve that could distinguish sterile males? Together with my students, I used a beetle Tribolium castaneum, which can be bred in Okayama, and measured the generational changes in female traits in an experimental area where sterile males and normal males were exposed to females, and in a control area where only normal males were exposed to females, by repeatedly breeding for more than 15 generations. In this seminar I would like to report and discuss the results.