Affiliation:
1. Neural Circuits and Evolution Laboratory, Francis Crick Institute, London NW1 1AT, UK
2. Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
Abstract
Tsetse flies significantly impact public health and economic development in sub-Saharan African countries by transmitting the fatal disease African trypanosomiasis. Unusually, instead of laying eggs, tsetse birth a single larva that immediately burrows into the soil to pupate. Where the female chooses to larviposit is, therefore, crucial for offspring survival. Previous laboratory studies suggested that a putative larval pheromone,
n
-pentadecane, attracts gravid female
Glossina morsitans morsitans
to appropriate larviposition sites. However, this attraction could not be reproduced in field experiments. Here, we resolve this disparity by designing naturalistic laboratory experiments that closely mimic the physical characteristics found in the wild. We show that gravid
G. m. morsitans
were neither attracted to the putative pheromone nor, interestingly, to pupae placed in the soil. By contrast, females appear to choose larviposition sites based on environmental substrate cues. We conclude that, among the many cues that likely contribute to larviposition choice in nature, substrate features are a main determinant, while we failed to find evidence for a role of pheromones.
Funder
Human Frontier Science Program
The Francis Crick Institute
EMBO
Biotechnology and Biological Sciences Research Council
European Research Council
Allen Foundation
UK Medical Research Council
Wellcome Trust
Cancer Research UK
Subject
General Agricultural and Biological Sciences,General Environmental Science,General Immunology and Microbiology,General Biochemistry, Genetics and Molecular Biology,General Medicine