Keywords: Sterile insect technique

Upscaling irradiation protocols of Aedes albopictus pupae within an SIT program in Reunion Island

34437
Lucie Marquereau, Hanano Yamada, David Damiens, Antonin Leclercq, Brice Derepas, Cécile Brengues , Brice William Dain , Quentin Lejarre 1, Mickael Proudhon , Jeremy Bouyer and Louis Clément Gouagna,  Scientific Reports,  14:12117. 2025-02-03 07:03:06.
The implementation of the sterile insect technique against Aedes albopictus relies on many parameters, in particular on the success of the sterilization of males to be released into the target area in overflooding numbers to mate with wild females. Achieving consistent sterility levels requires efficient and standardized irradiation protocols. Here, we assessed the effects of exposure environment, density of pupae, irradiation dose, quantity of water and location in the canister on the induced sterility of male pupae. We found that the irradiation of 2000 pupae in 130 ml of water and with a dose of 40 Gy was the best combination of factors to reliably sterilize male pupae with the specific irradiator used in our control program, allowing the sterilization of 14000 pupae per exposure cycle. The location in the canister had no effect on induced sterility. The results reported here allowed the standardization and optimization of irradiation protocols for a Sterile Insect Technique program to control Ae. albopictus on Reunion Island, which required the production of more than 300,000 sterile males per week.

Animal trypanosomosis eliminated in a major livestock production region in Senegal following the eradication of a tsetse population

34426
Momar Talla Seck, Assane Guèye Fall, Adji Marème Gaye, Geoffrey Gimonneau, Mamadou Ciss, Mame Thierno Bakhoum, Baba Sall, Mireille Djimangali Bassène1, Renaud Lancelot, Marc J.B., Vreysen, and Jérémy Bouyer,  Parasite 31,  31. 2025-02-03 04:43:45.
African animal trypanosomosis (AAT) was one of the main disease-related constraints to the development of intensive livestock production systems in the Niayes region of Senegal, a 30 km wide strip of land along the coast between Dakar and Saint-Louis. To overcome this constraint, the Government of Senegal initiated an area-wide integrated pest management programme combining chemical control tactics with the sterile insect technique to eradicate a population of the tsetse fly Glossina palpalis gambiensis Vanderplank, 1949 (Diptera, Glossinidae) in this area. The project was implemented following a phased conditional approach, and the target area was divided into three blocks treated sequentially. This study aims to assess the temporal dynamics of the prevalence of Trypanosoma spp. during the implementation of this programme. Between 2009 and 2022, 4,359 blood samples were collected from cattle and screened for trypanosomes using both the buffy coat and ELISA techniques, and PCR tests since 2020. The seroprevalence decreased from 18.9% (95%CI: 11.2–26.5) in 2009 to 0% in 2017–2022 in block 1, and from 92.9% (95%CI: 88.2–97) in 2010 to 0% in 2021 in block 2. The parasitological and serological data confirm the entomological monitoring results, i.e., that there is a high probability that the population of G. p. gambiensis has been eradicated from the Niayes and that the transmission of AAT has been interrupted in the treated area. These results indicate the effectiveness of the adopted approach and show that AAT can be sustainably removed through the creation of a zone free of G. p. gambiensis.