Warming has already boosted insect breeding

Susan Milius in Science News: Summertime and the insect breeding is easy. That old song rings especially true for 44 species of moths and butterflies in Central Europe, according to an analysis by ecologist Florian Altermatt of the University of California, Davis. As the region has warmed since the 1980s, some of these species have added an extra generation during the summer for the first time on record in that location.

Among the 263 species already known to have a second or third generation there during toasty times, 190 have grown more likely to do so since 1980, Altermatt reports online December 22 in Proceedings of the Royal Society B.

Only a rough third or so of all the species Altermatt reviewed show the capacity to breed more than once a year. What warming is probably doing for them, he speculates, is jolting the insects’ overwintering form into action early and also speeding up insect development. These head starts may allow time for a bonus generation before a non-temperature cue, atumnal day length, plays its role in shutting down insects for winter.

“From a pest perspective it’s an important issue,” says population ecologist Patrick Tobin based in Morgantown, W.Va., for the Forest Service Northern Research Station. Tobin has studied a warmth-related extra generation in a North American pest, the grape berry moth. He points out that an extra surge of attacking pests in the growing season means yet another headache, expense and round of damage for farmers….

A monarch butterfly, shot by Inzilbeth, Wikimedia Commons, under the terms of the GNU Free Documentation License, Version 1.2