Why are Ladybugs Swarming All Over McCabe?

If you’ve been to McCabe library during daylight hours the past few days, you must have noticed the swarms of what appear to be ladybugs crowding around the front doors and windows. As such, you may be asking yourself: why ladybugs, why now, and why are they trying to get into McCabe?

As per their swarming behavior and our location, it’s probable that the insects currently attempting to enter the confines are not native ladybugs, but rather are Asian lady beetles, an invasive species with few predators in the Eastern United States. Are the ladybugs—as our weather joke two days ago would suggest—attempting to breed madly before they die in the winter? Perhaps not. Their swarming behavior may have been activated by our local weather patterns—a period of marked coldness followed by a warm spell on a sunny day, as we all can recall—indicating to the beetles that it is time to engage in the process of overwintering. In the insect world, overwintering is a behavior wherein the insects attempt to find a location in which they can try to survive the winter to emerge again in the spring.

Why McCabe, though? Unclear, but we’ll offer a piece of conjecture: If, as suggested by our sources, the beetles are attempting to find locations with cracks and openings, perhaps McCabe happens to be a location with enough access to be a solid, accessible overwintering location for the frantic creatures. (Just don’t try to crush them to prevent their success: the beetles evidently leave a smelly, yellowish stain upon their deaths—yuck!) When/if we see an outpouring of ladybugs bursting from McCabe come Spring, we’ll know that they survived… and, perhaps, that McCabe could use some patching-up!

The Daily Gazette—and the Swarthmore community, assuredly—would appreciate any further conjecture or informed commentary from amateur or actual entomologists on this point.

Got a question burning on your mind? Spotted any more mysterious insect swarms? Ask the Gazette at ask@daily.swarthmore.edu!