Ombura Fidelis L O, Abd-Alla Adly M M, Akutse Komivi S, Runo Steven, Mireji Paul O, Bateta Rosemary, Otiwi Joseck E, Ajene Inusa J, Khamis Fathiya M
International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, Nairobi, Kenya.
Front Microbiol. 2024 Dec 9;15:1472324. doi: 10.3389/fmicb.2024.1472324. eCollection 2024.
Tsetse flies and trypanosomosis significantly impact bovine production and human health in sub-Saharan Africa, exacerbating underdevelopment, malnutrition, and poverty. Despite various control strategies, long-term success has been limited. This study evaluates the combined use of entomopathogenic fungi (EPF) and the sterile insect technique (SIT) to combat tsetse flies. Eleven EPF isolates were tested against teneral males of , focusing on mortality rates, radial growth, and impacts on fly fitness. Temperature effects on conidial growth, sporulation, and spore yield of SIT-compatible/tolerant strains were also assessed. The fungal isolates significantly influenced mortality rates in both unirradiated and irradiated (SIT-treated) males ( < 0.0001). strains ICIPE 20, ICIPE 32, ICIPE 41, ICIPE 62, ICIPE 78, and ICIPE 603 showed higher SIT compatibility/tolerance with LT values of 11-30 days, compared to other more virulent isolates with LT values of 4-9 days. Temperature significantly affected the radial growth of SIT-compatible EPF strains ( < 0.0001), with ICIPE 78 exhibiting the fastest conidia growth at 25°C. Spore yield varied significantly across temperatures (15-40°C), and the thermal range for conidia germination of SIT-compatible strains was 8.1-45.4°C, with an optimal range of 26.7-31.1°C. Moreover, infected unirradiated females and irradiated males (donors) successfully transmitted conidia to untreated flies (receivers) without significant differences in survival rates ( = 0.6438) and no observed sex dimorphism. Our findings highlight the potential of combining EPF and SIT as a novel dual approach that could effectively and synergistically suppress tsetse fly populations.
采采蝇和锥虫病对撒哈拉以南非洲的牛生产和人类健康产生了重大影响，加剧了不发达、营养不良和贫困状况。尽管采取了各种控制策略，但长期成效有限。本研究评估了昆虫病原真菌（EPF）与不育昆虫技术（SIT）联合使用以对抗采采蝇的效果。对11株昆虫病原真菌分离株针对[某种采采蝇]的 teneral 雄蝇进行了测试，重点关注死亡率、径向生长以及对蝇类适应性的影响。还评估了温度对与SIT兼容/耐受菌株的分生孢子生长、产孢和孢子产量的影响。真菌分离株对未辐照和辐照（经SIT处理）雄蝇的死亡率均有显著影响（P<0.0001）。与其他LT值为4 - 9天的毒性更强的分离株相比，ICIPE 20、ICIPE 32、ICIPE 41、ICIPE 62、ICIPE 78和ICIPE 603菌株表现出更高的SIT兼容性/耐受性，LT值为11 - 30天。温度对与SIT兼容的昆虫病原真菌菌株的径向生长有显著影响（P<0.0001），ICIPE 78在25°C时分生孢子生长最快。孢子产量在不同温度（15 - 40°C）下差异显著，与SIT兼容菌株的分生孢子萌发温度范围为8.1 - 45.4°C，最佳范围为26.7 - 31.1°C。此外，受感染的未辐照雌蝇和辐照雄蝇（供体）成功地将分生孢子传播给未处理的蝇（受体），存活率无显著差异（P = 0.6438），且未观察到性别二态性。我们的研究结果突出了将昆虫病原真菌和不育昆虫技术结合作为一种新型双重方法的潜力，该方法可以有效且协同地抑制采采蝇种群。
