Proboscis infection route of Beauveria bassiana triggers early death of Anopheles mosquito

• Published in: Scientific Reports Vol. 7; no. 1; pp. 3476 - 10
• Main Authors: Ishii, Minehiro, Kanuka, Hirotaka, Badolo, Athanase, Sagnon, N’Falé, Guelbeogo, Wamdaogo M., Koike, Masanori, Aiuchi, Daigo
• Format: Journal Article
• Language: English
• Published: London Springer Science and Business Media LLC 14.06.2017; Nature Publishing Group UK; Nature Publishing Group; Nature Portfolio
• Subjects: 14/63; 631/326/193/2542; 631/601/1466; Animals; Anopheles; Anopheles - microbiology; Aquatic insects; Beauveria; Beauveria - physiology; Beauveria bassiana; Brain; Brain - microbiology; Culicidae; Death; Entomopathogenic fungi; Filter paper; Fungal infections; Humanities and Social Sciences; Hyphae; Inoculation; Medicine; Mortality; Mosquito Control; Mosquito Vectors; Mosquito Vectors - microbiology; Mosquitoes; multidisciplinary; Pest control; Pests; Proboscis; Q; R; Science; Science (multidisciplinary); Survival Analysis
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-03720-x

Entomopathogenic fungi are known to control vector mosquito populations. Thus, understanding the infection dynamics of entomopathogenic fungi is crucial for the effective control of insect pests such as mosquitoes. We investigated the dynamics of Beauveria bassiana s.l . 60-2 infection of Anopheles stephensi by exposing the mosquito to fungus-impregnated filter paper through two infection routes and then comparing the mortality and extent of infection. Fungal development was observed after using this inoculation method with both the tarsus route and the proboscis route, but early mosquito death occurred only after infection through the proboscis route. Fungal hyphae invaded almost all the tissues and organs before or after the death of the host, and fungal invasion of the brain was highly correlated with mortality. Moreover, although all mosquitoes that were alive at various time points after inoculation showed no fungal infection in the brain, fungal infection was detected in the brain in all dead mosquitoes. Our results suggest that fungal invasion of the brain represents one of the factors affecting mortality, and that the proboscis route of infection is critical for the early death of vector mosquitoes.