February ended with cold, snowy conditions that we have not seen in quite a few years. Oftentimes when we experience these conditions, the first question I hear is “will this reduce the bug population this summer?” Unfortunately, the majority of our insects are well adapted to survive much colder conditions than we experienced in February. Also, the snow cover likely served as insulation and protected many from freezing. Therefore, not many of our 2021 insects will be impacted by the cold temperatures. So, how is that possible, you may ask?
Insects are cold blooded and have different survival methods. One method is they use proteins and sugar alcohols that lower their freezing point, so ice does not damage tissues. This is kind of like an insect’s version of antifreeze. Some insects migrate to warmer temperatures. The monarch butterfly is a classic example of this where the adults fly to Mexico to overwinter and return to southern Indiana in the spring.
Other insects will burrow into the ground, then resurface in the spring when temperatures warm. Ants, for example, will move into deeper nests underground and huddle together in their colonies to keep warm. This may appear that they are hibernating, but in the insect world it is called diapause. Diapause is when an insect goes into a dormant state that allows them to survive the cold weather.
To go dormant it takes time for them to adapt. When insects have time to adapt gradually to the cold and it remains cold they are more able to survive the winter. If fall temperatures have fluctuating temperatures it makes it more difficult for them to adjust and overwinter. Insects are also less able to tolerate rapid cold snaps, such as those caused by Artic clipper versus long cold periods like we saw in February. Insects may also be killed by cold weather if we have warmer periods that last for extended periods of time over the winter months where they wake up from their winter slumber then we have an intense cold spell or a late spring frost. Although many of our insects may not have been impacted by our cold February, this also means our beneficial insects should still be around to manage the nuisance insects. Also, this will hopefully be good for birds or other predators that feed on insects.