(Note: this post has been revised to clarify that the convergent lady beetle is native in North America – though it is being moved around as a pest control agent, including into parts of South America, where it isn’t native.)
I saw two native ladybugs this week at our Platte River Prairies, which shouldn’t be as notable as it is. Unfortunately, over the last 20 years, native ladybug populations have steeply declined – especially among some species, which are almost never seen anymore in many places. During the same time, non-native ladybugs (lady beetles) have dramatically increased in abundance. As a result, the vast majority of lady bugs I see are non-native (particularly the 7-spotted and Asian lady beetles). Finding a native species is a cause for celebration.
Frequent readers of this blog will know that competition from honey bees (non-native species) has contributed to the decline of native bees in North America. There are many other factors, though, linked to those bee declines and it’s hard to know exactly how important honey bee competition is. A similar problem exists with investigations into disappearing ladybugs. There are certainly strong correlations between increases in non-native ladybug abundance and decreases in native species populations. However, habitat loss and degradation, pesticide use, and many other factors are at play as well.
Scientists continue to delve into this and there are opportunities for you to help. For example, the Lost Ladybug Project is a community science effort that encourages people to send in photos of both native and non-native ladybugs to build understanding about changes in populations. Their website has information about how to become involved, but also some great information on how to identify ladybug species. For people in the Great plains, a particularly nice resource linked to on that site is the Ladybugs of South Dakota poster, which has terrific photos of 80 ladybug species. I’ve found it to be an easy and very helpful tool to identify species.
Ladybugs are an easy group of insects to learn because their spot patterns make them relatively easy to identify (though some of the species – especially the Asian lady beetles – can be variable in appearance.) Whether or not you join in community science efforts related to ladybugs, it’s important to be aware of what species you see around you. The two photos above show the most common non-native ladybugs seen around Nebraska. If you see something that looks like a ladybug and it doesn’t look like one of those two, take note. Even better, take a picture!
Once you have a decent photo, you’ll have a good chance of identifying the species. If you can’t figure it out, you can submit it to iNaturalist, Bugguide, or other sources. Pretty soon, you’ll become familiar with what the non-natives look like. The bad news there is that you’ll probably start to realize how dominant they’ve become in your area. The good news is that when you actually find a native species you’ll know it’s time to celebrate!