Lady Beetle Larva

2017 November 25

Sam found this beetle larva crawling across our carpet on September 24, 2017.


This is most definitely a lady beetle larva. Most likely the Multicolored Asian Lady Beetle, Harmonia axyridis, which judging from the BugGuide pictures has exactly this color scheme (along with that particular pattern of spiky growths on the abdomen).


It wasn’t too terribly big, here it is on my fingertip for a sense of scale.


Finding these in the house is no cause for alarm, since they are strictly carnivorous. If anything, they would eat other insects in the house that we do object to. Their mouthparts aren’t too aggressively predatory, but obviously are adequate for eating soft-bodied insects like aphids.


So, this is a species that we’ve seen before, although that last posting was from 2008. That was a real boom year for these beetles, they were everywhere and got into everything. But then, the next year their population crashed, and we didn’t see them again in any significant quantity.

Until this year, that is. After finding this larva, the adult lady beetles started getting in to the house in some numbers, looking for a place to hibernate. Sam started catching them and keeping them in a jar[1], and she currently has around 20 of them. These are just the ones she could reach, there are other clusters of them up in the top corners of most of our window frames. It is nothing like the last boom year, when we had hundreds of them in the house (sometimes flying around the lights in the evenings), but still they have clearly bounced back.

So, at the moment it is looking like about a 10-year boom/bust cycle, which would mean that next year we can expect to be inundated with these lady beetles again.

[1] She gives them a little piece of fruit (a grape, orange segment, or small apple slice) every few days, which they seem to be happy enough to eat. We unfortunately don’t have any aphids for them. From past experience, the ones that try to overwinter in the house eventually dry out and die anyway, so these probably have a better chance for survival than the ones that she didn’t catch.

2 Responses
  1. Carole permalink
    November 25, 2017

    I’ve read that these Asian beetles carry a parasite that is killing our native ladybugs. I’ve been killing them.

  2. November 27, 2017

    Carole: wow, that’s really bad. So, basically, lady beetles tend to eat each other’s eggs. And the Asian beetles have a parasite in their eggs that doesn’t affect them, but that kills other lady beetle species. So the asian beetles can eat the eggs of other lady beetles, but the other lady beetles die if they return the favor. Unfortunately, there are so many of the asian beetles around that killing them won’t even make a dent in the population.

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