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!
Print
Email
#1: 10/23/2009 at 7:19 a.m.
Trotter also has tons of them on the ceiling in the stairwell.
— Seth Green | Registered, Swarthmore
#2: 10/23/2009 at 8:07 a.m.
It wasn't just McCabe. My seminar in trotter spent about 5 minutes contemplating why over 15 ladybugs were bombarding the windows of trotter, and my room in Parrish also had 4-10 ladybugs consistently crawling all over it. I'm sure these bugs can find cracks just about anywhere, given that yesterday alone no less than 5 landed on me and tried to take refuge in the folds of my clothing.
— Steve | Unregistered, Swarthmore
#3: 10/23/2009 at 8:58 a.m.
THESE THINGS ARE EVERYWHERE.
— Corin | Unregistered, Swarthmore
#4: 10/23/2009 at 9:13 a.m.
they are also mating on my room ceiling, above MY. BED!
— ladybughater | Unregistered, Swarthmore
#5: 10/23/2009 at 10:24 a.m.
Excellent article. You hit it on the dot. My friend who is a not-so-amateur entomologist agrees.
— buglover | Unregistered, Swarthmore
#6: 10/23/2009 at 10:46 a.m.
You are correct. I came from DE, so they invaded my house every year about this time. Also, Wharton seems to attract the bugs as well...it must be stone buildings in general.
— Josh | Unregistered, Swarthmore
#7: 10/23/2009 at 12:59 p.m.
Wesleyan U. in CT is actually having the same problem with lady bugs swarming their main library.
There's an article about it in their paper: the argus.
must be smart bugs...
— oddly enough | Unregistered, Swarthmore
#8: 10/23/2009 at 1:18 p.m.
You guys are right about their being an invasive species. Good work.
— Argos | Unregistered, Swarthmore
#9: 10/23/2009 at 9:38 p.m.
Yup, I think it's the stone buildings--they were swarming around the entrance to Willets, too.
— Miriam | Unregistered, Swarthmore
#10: 10/24/2009 at 12:35 p.m.
My understanding is that they are attracted to whitish colored walls and structures (a light contrast with surrounding darker patches is also apparently particularly attractive), especially those with a sunny southern exposure, as these mimic the limestone caves in East Asia where the species used to spend the winter before arriving here.
— Andrew | Unregistered, Non-Swarthmore