Global warming harms insect reproduction

Posted Jan 15, 2017 by Tim Sandle
Several studies have shown how climate change is affecting insect populations, results in death. A new study takes a different approach and shows how global warming is affecting the ability of some insects to reproduce.
The study, carried out by scientist’s from the University of Sheffield, U.K., found that heat stress affects insect reproduction and also that the effect of increasing temperature affects insects living in colder climes more greatly than insects living in warmer areas. This means insects that habit northern latitudes are more vulnerable than those that are southern-dwelling.
A further complication is that many insects are not very good at adapting to ecological changes, with few species being migratory and being able to move to new habitats. This is especially so for insect larvae or those developed into small nymphs. Discussing this with BBC Science, lead researcher Dr. Rhonda Snook adds: “You get an extreme heat weather event that the insect cannot escape from because they are juveniles, so they can't move as much.”
She also commented: “They live through it because it does not kill them, but then they have the subsequent problem of reproducing.”
The researcher’s comments are based on laboratory experiments designed to replicate the conditions of the gradual warming of the planet. Here fruit flies were exposed to a rise in temperature of 5.5 degrees Celsius (just under 10 degrees Fahrenheit). This temperature rise was sufficient to prevent the majority of the numbers studies from being able to reproduce.
With the fruit flies, there were differences between those from Spain and those from Sweden, with the Swedish fruit flies being less resistant. This is due to what biologists refer to as “predominant selection pressure”, which relates to the fruit flies found in warmer climate adapting better.
The next phase of the research is to repeat the studies using other insects. The fruit fly, as model organisms in biological research, provides a representative starting point but they will probably be variations with other insects.
The research has been published in the Journal of Evolutionary Biology. The research paper is titled “Local adaptation of reproductive performance during thermal stress.”