Predaceous Toxorhynchites mosquitoes require a living gut microbiota to develop

Area of Science:

• Microbiology
• Entomology
• Developmental Biology

Background:

• Most mosquito species are detritivores, consuming decaying matter and hosting environmental microbes.
• Detritivorous mosquitoes typically require a living gut microbiota for larval development beyond the first instar.
• Predatory mosquitoes, like Toxorhynchites, feed on other organisms, raising questions about their microbial dependence.

Purpose of the Study:

• To investigate whether predatory Toxorhynchites amboinensis larvae require gut microbes for development.
• To determine if the microbial requirements of predatory mosquitoes differ from detritivorous species.

Main Methods:

• Larval development assays using axenic (bacteria-free) and gnotobiotic (known bacteria) Aedes aegypti prey.
• Bacterial community analysis of Toxorhynchites amboinensis larvae.
• Functional assays to assess the role of specific bacterial species in development.

Main Results:

• Toxorhynchites amboinensis larvae harbored bacterial communities similar to their Aedes aegypti prey.
• Axenic Toxorhynchites amboinensis larvae failed to develop.
• Colonization with two specific bacterial species from prey rescued development in gnotobiotic larvae.
• Axenic larvae showed growth defects linked to microbe-mediated gut hypoxia.

Conclusions:

• Gut microbes play a conserved role in regulating mosquito development, irrespective of feeding strategy.
• Predatory mosquitoes, like detritivorous ones, depend on gut microbiota for successful larval development.
• Microbe-mediated gut hypoxia is crucial for nutrient acquisition in mosquitoes, supporting conserved developmental roles.