A study published in the September issue of the journal Ecology reveals that a decrease in global wind speeds in recent years, otherwise known as “wind stilling,” may have an indirect effect on the relationship between predator and prey interactions, particularly in insects.

According to the study, global wind speeds have been on the decline by up to 15 percent in the last 30 years, and the effects of wind on predator-prey interactions within communities is still widely unknown.

“There are all sorts of other things that are changing in the environment that affect animals and plants and their interactions,” said Brandon Barton, lead investigator from the University of Wisconsin in Madison, in a recent statement. “My students and I were standing out in a cornfield one day as big gusts of wind came by, and the corn stalks were bending almost double. From the perspective of an animal living in the corn, we thought, ‘That’s got to have a big effect.’”

In order to investigate the effects of wind on predator-prey interaction, Barton utilized soybean aphids as prey and multicolored Asian ladybeetles as predator. In the study, soybean plots were grown in an alfalfa field, and wind effects were examined on soybean aphids – without predators – under three treatments: no wind, wind generated by an oscillating fan, and simulated wind movement.

A field experiment was then conducted in the soybean plots to include the predators, dividing the plots into either those protected by the wind through wind blocks or those simply left out in the open field. Observations revealed an interesting occurrence throughout the experiment.

“The aphids appear on the plants whether it’s windy or not, and we showed that in lab experiments,” said Barton. “But when you add the predators, with the wind block, the beetles eat something like twice as many aphids.” In particular, he found two-thirds as many ladybeetles in the soybean plots hidden from the wind and twice as many soybean aphids on the plots left out in the open.

The idea is that the changing environment, due to wind reduction, possibly affects the foraging abilities of the insect predators. “If the plant is moving, it takes four times as long for the predator to start eating, and it eats less than half as many aphids in an hour,” said Barton.

The results from the study also have implications for altered pest control and a reduction on pesticides in the harvesting fields by reducing wind movement. “By growing trees or not harvesting them around a field, you may be able to have an indirect effect on the number of aphids on your soybean plants,” said Barton.

The study author also suggests that this effect may go beyond the predator-prey interaction of insects. “Think of a wolf or coyote. Larger predators hunting by scent – and the prey trying to detect their predators – may be affected by less wind moving scents around.”

“Reduced wind strengthens top-down control of an insect herbivore,” written by Brandon T. Barton, was published in the Sept. 2014 issue of Ecology.