Insects Predict the Weather: Mating Behavior Modified by Air Pressure

While your local weatherman may not be able to precisely predict the weather, it turns out that insects can. Scientists have discovered that these six-legged creatures modify their calling and courting mating behavior in response to changes in air pressure. The findings reveal a little bit more about how adept insects are at sensing the environment around them.

In order to learn a little bit more about how insects adapt to weather, the researchers examined the mating behavior changes in the curcurbit beetle, the true armyworm moth and the potato aphid. More specifically, they examined the insects under falling, stable and increasing air pressure conditions. This allowed them to see how they responded to varying "weather" conditions.

So what did they find? When researchers measured the male beetles' response to female sex pheromones under the different conditions, they found a significant decrease in pheromone response when air pressure fell compared to stable or increasing pressure. In addition, about 63 percent of males started copulating faster in the presence of females during dropping atmospheric pressure, a condition associated with high winds and rains. In contrast, under stable or rising air pressure conditions, all males showed full courtship behavior.

That's not all they found, though. The scientists also noted that the female armyworms' calling was reduced during decreasing air pressure, but that the potato aphid showed reduced calling both during decreasing and increasing air pressure, two conditions that can occur with high winds. In both cases, reduced calling went hand-in-hand with reduced mating behavior.

"The results presented show that three very different insect species all modify aspects of their sexual behavior in response to changing barometric pressure," said Jose Mauricio Bento, one of the researchers, in a news release. "However, there is a great deal of interspecific variability in their responses that can be related to differences in size, flight ability and the diel periodicity of mating."

The findings reveal a little bit more about how these insects reaction to weather conditions. In addition, it reveals that an insect's ability to predict adverse weather conditions may help it modify mating behavior in order to reduce the risk of injury or even death.

The findings are published in the journal PLOS One.