The internet is a wonderful place; all the information you could ever want is at your finger tips. It’s the ultimate vessel for information…. and misinformation. Some misinformation seems to go viral, and those who are trying to correct that information feel like they are just screaming into the void.
Well, here is one such scream into the void. If you’re reading, thank you.
Dismantling the Myth about the “Asian Lady Beetle.”
You’ve seen a picture like this before. “Ladybug vs Lady Beetle,” or you’ve heard someone rant about how that ladybug is a bad one and should be destroyed. And some of you are thinking “huh… I always thought those ladybugs were good.” So, let’s get to the actual, inarguable information so you can be more sure of who are friends and who are foes.
First, question the source of that information. (Pretty decent illustrations, I must admit). The fact that the author/creator is comparing The Asian Lady Beetle, which is an introduced species, with the Seven Spotted LadyBug and claiming it is “native,” means that they are from Europe. For anyone in North America, this is just showing you two introduced species – both of whom eat aphids.
Latin names are important, albeit, hard to pronounce and easy to forget. The “Asian Lady Beetle” is a new term for Harmonia axyridis. Formerly, it was well known by names like “the Harlequin LadyBug,” and the “Many-coloured Ladybird.” It’s best to call it Harmonia axyridis (or Harmonia) to avoid both negative connotations and to avoid confusion – since “Ladybug,” “Lady Beetle,” and “Ladybird” are all interchangeable, common names that do more to describe where you’re from than anything specific about the beetle.
All Ladybugs, Ladybirds and Ladybeetles are coccinellid beetles. Which you can group together as being the rounded-back beetles. Beetles are the largest group of insects and so just like beetles-in-general, coccinellids have a huge variety. The colourations are as diverse as the food they eat. For example, there are all black ones that eat spider mites, and there are ones patterned like a Rorschach inkblot that eat mildew. Even amongst the big, coloured ones (that are often amongst the first bugs you notice as a kid) there are all sorts of spots and colours, each (usually) a distinguishing feature of a separate species.
Harmonia axyridis eat aphids. Yes, like many other coccinellids, they are “generalists,” (meaning they eat many different bugs) but they tend to need aphids to reproduce. This isn’t because aphids are anything special, but it is because aphid infestations typically include high numbers and accompanying honeydew. It’s the large numbers that trigger Harmonia to lay eggs, and the honeydew that attracts them in the first place.
Harmonia are not dangerous to you or your pets. There was a story of a dog that ate some and died, but this has been fact checked: The dog had a habit of eating everything, and he ate hundreds or thousands of them, and did die. But it was not because the beetle should be considered harmful, it was just the pure volume it ate. So, the only concern is that you might have a pet that will eat anything, and at the same time you could be the type of person who leaves buckets of ladybugs laying around: the perfect storm!
But they do bite. And that’s just something you should know about all ladybugs. Because they all do it. Even the tiny micro-coccinellid Delphastus catalinae will bite, and you’ll feel it. The bits aren’t toxic or venomous, so just be aware. And maybe don’t harass them so much.
Harmonia is an introduced species. You may also call it a foreign species. It is not necessarily “invasive,” but that is largely based on how you or your government look at it. For a plant or animal to get the “invasive” tag it needs to be both foreign and a danger to health, the environment or the economy. The problem is, countless studies have now looked at the impact of Harmonia populations and found that the information is still too vague to conclude if it is a detriment to the environment.
Case, in point: areas where the populations of Harmonia have increased, tend to be areas with lots of farm land. In many places in North America where native coccinellid species still thrive tend to be more diverse with either more forest or more parkland. Studies conducted at Kansas State found that Harmonia arrived early on crops of wheat, built up numbers and then provided aphid control to the subsequent arrival of Sorghum and the Sorghum Aphid. In areas without Harmonia, these aphids are not controlled by native coccinellids. Therefore, it is believed that Harmonia do well in field crops where they can complete their life cycle. So, they have found a niche – and an important one, if you’re a farmer.
And, that is why they were introduced. Several times the USDA released Harmonia because a new “invasive” aphid was causing problems. Interestingly, the genetics of the ones they released do not match with those established North American populations, but nevertheless, Harmonia was brought all over the world from its native territory of Asia.
Finally, we get to the subjective part of it: Are they good, or bad? Official “control” of Harmonia from government publications is almost always limited to preventing them from going indoors. This is why some see them as a pest. They are not picky about where they diapause (hibernate). But they do so in huge numbers and places that are warm. So, if they are in your house, and not wanted in your house, you can define them as a pest and maybe even consider them “bad.” In the garden, it is not so clear. Are they displacing native ones? No one can say for sure. Since they eat all sorts of things, are they eating more beneficial insects than pests? (Not likely). So, do you need to be concerned about the “harmful Asian Lady Beetle?” Not if you close your windows.
So, there you have it. The Harmonia axryidis that you find in your yard is there to eat aphids. It is introduced, but should cause no more alarm than your “introduced” tomato plants. You dog might get sick if it eats a bunch of them….but it might get sick if it eats a bunch of your tomato plants too.