A rapid quality control test to foster the development of the sterile insect technique against Anopheles arabiensis

• Published in: Malaria Journal
• Main Authors: Nicole J. Culbert, Nanwintoum Séverin Bimbilé Somda, Maiga Hamidou, Dieudonné Diloma Soma, Silvana Caravantes, Thomas Wallner, Mamai Wadaka, Hanano Yamada, Jérémy Bouyer
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2020
• Subjects: Sterile insect technique (SIT); Malaria; Flight ability; Quality control (QC); Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-020-3125-z; https://doaj.org/article/14af2a486bd84224b930154d628ff201

Abstract Background With the fight against malaria reportedly stalling there is an urgent demand for alternative and sustainable control measures. As the sterile insect technique (SIT) edges closer to becoming a viable complementary tool in mosquito control, it will be necessary to find standardized techniques of assessing male quality throughout the production system and post-irradiation handling. Flight ability is known to be a direct marker of insect quality. A new version of the reference International Atomic Energy Agency/Food and Agricultural Organization (IAEA/FAO) flight test device (FTD), modified to measure the flight ability and in turn quality of male Anopheles arabiensis within a 2-h period via a series of verification experiments is presented. Methods Anopheles arabiensis juveniles were mass reared in a rack and tray system. 7500 male pupae were sexed under a stereomicroscope (2500 per treatment). Stress treatments included irradiation (with 50, 90, 120 or 160 Gy, using a Gammacell 220), chilling (at 0, 4, 8 and 10 °C) and compaction weight (5, 15, 25, and 50 g). Controls did not undergo any stress treatment. Three days post-emergence, adult males were subjected to either chilling or compaction (or were previously irradiated at pupal stage), after which two repeats (100 males) from each treatment and control group were placed in a FTD to measure flight ability. Additionally, one male was caged with 10 virgin females for 4 days to assess mating capacity (five repeats). Survival was monitored daily for a period of 15 days on remaining adults (two repeats). Results Flight ability results accurately predicted male quality following irradiation, with the first significant difference occurring at an irradiation dose of 90 Gy, a result which was reflected in both survival and insemination rates. A weight of 5 g or more significantly reduced flight ability and insemination rate, with survival appearing less sensitive and not significantly impacted until a weight of 15 g was imposed. Flight ability was ...