Bugs are coming

Q. Will this year be buggy since it has been such a warm winter?

Maggie from Youngstown

A. There is no concise sound bite or tweet-worthy answer. It’s complicated by the wide-ranging strategies used by insects to successfully deal with winter conditions.

The answer is made even more complicated because evolutionary selective advantages that reward one strategy over another haven’t been consistent across taxonomic groups.

So, we can’t say that all beetles deal with winter in a certain way, or all flies, or all bees. Questions spawned by warm winters are at the opposite end of those that arise from winters dominated by lower-than-average temperatures, but the same principles apply.

At one end of the spectrum are insects that clearly benefit from warmer than average winters. Goldenrain Tree Bugs (Jadera haematoloma) appeared in large numbers on their namesake host in southern Ohio during 2012 and 2013 growing seasons. This native insect is common in Florida, where it feeds on the seeds of plants in the soapberry family. They disappeared from Ohio during the winter of 2013-14, however. The rise and fall of these insects in relation to higher- or lower-than-average winter temperatures adds support to the perception that a warm winter means more insect pests. Of course, the winter survival of these insects was based more on luck than evolutionary advantage. This is not the case for most of our Ohio insect pests.

Some southern insects give up the ghost in Ohio during even our mildest winters, but they reappear in our state in the spring or early summer by being blown north from their southern winter enclaves. Potato Leafhopper (Empoasca fabae) is the poster child for this seasonal repopulation strategy.

Other insects handle Ohio winters by seeking over-wintering locations where temperatures remain moderate. Insects that spend the winter hiding from the cold prepare themselves by accumulating fat in the fall then they live off the fat through the winter. A warm winter may mean they can literally starve to death because they are not feeding, and high temperatures increase their metabolism causing them to consume their fat reserves.

Other insects are simply unaffected by even our coldest winters because they can protect themselves with antifreeze – literally. It’s not cold weather that kills insects; it’s sharp-pointed ice crystals that form below 32 degrees to pierce and destroy cells that kills insects.

The bottom line is that overwintering strategies of insects are varied and complicated, meaning that we can’t paint with a broad brush to predict what effect, if any, our balmy winter weather will have.

Today’s answer provided by Joe Boggs, OSU Extension. For details, visit http://go.osu.edu/insectsurvival.