Nemoptera bipennis. Credit: Vanesa Castejón

Scientists from the Estación Biológica de Doñana - CSIC performed a scientific literature review to find out how temperature influences development in insects. Specifically, the research has focused on Neuroptera, predatory insects that play an essential role in ecosystem pest management. How do the life cycles of these species vary and how much of this variation is explained by temperature?

The results indicate that higher temperatures are associated with an acceleration of growth and development in Neuroptera, along with increased metabolic activity, facilitating faster development of eggs, larvae and pupae. However, such faster development may be associated with lower survival and reproduction as temperatures warm. The results are in line with previous studies suggesting that high and low temperatures may decrease survival and reproductive output and thus population viability. For instance, if individuals develop faster and have relatively smaller body sizes, high temperatures may cause them more stress and cause females to suffer higher relative moisture loss, higher evaporation and overheating, which negatively affects their survival and reproductive function.

Important research in the face of climate change

Insects play an essential role in all ecosystems and are increasingly exposed to higher temperature extremes under climate change. Unlike birds or mammals, they lack the ability to maintain a constant body temperature and are very sensitive to variations in environmental temperature. To mitigate potential risks, they have developed mechanisms and molecular responses to different temperature conditions, which can influence their development and growth and lead to phenological alterations.

The results show that it is necessary to predict how not only charismatic species, but also less studied but very important animals for the functioning of ecosystems such as insects, respond to temperature conditions throughout their life cycle. Faster development times may not necessarily lead to higher abundances due to differential temperature responses across life cycle.