Unexpected consequences of a drier world: evidence that delay in late summer rains biases the population sex ratio of an insect

The complexity of animal life histories makes it difficult to predict the consequences of climate change on their populations. In this paper, we show, for the first time, that longer summer drought episodes, such as those predicted for the dry Mediterranean region under climate change, may bias inse...

Full description

Saved in:
Bibliographic Details
Published in:Royal Society open science 2015-09, Vol.2 (9), p.150198-150198
Main Authors: Bonal, Raul, Hernández, Marisa, Espelta, Josep M., Muñoz, Alberto, Aparicio, José M.
Format: Article
Language:English
Subjects:
Biology (whole Organism)
Climate Change
Drought
Insects
Sex Ratio
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The complexity of animal life histories makes it difficult to predict the consequences of climate change on their populations. In this paper, we show, for the first time, that longer summer drought episodes, such as those predicted for the dry Mediterranean region under climate change, may bias insect population sex ratio. Many Mediterranean organisms, like the weevil Curculio elephas, become active again after summer drought. This insect depends on late summer rainfall to soften the soil and allow adult emergence from their underground refuges. We found that, as in many protandric species, more C. elephas females emerged later in the season. Male emergence timing was on average earlier and also more dependent on the beginning of late summer rainfall. When these rains were delayed, the observed weevil sex ratio was biased towards females. So far, the effects of global warming on animal sex ratios has been reported for temperature-dependent sex determination in reptiles. Our results show that rainfall timing can also bias the sex ratio in an insect, and highlight the need for keeping a phenological perspective to predict the consequences of climate change. We must consider not just the magnitude of the predicted changes in temperature and rainfall but also the effects of their timing.
ISSN:2054-5703
2054-5703
DOI:10.1098/rsos.150198