Invertebrates
Convergent Lady Beetle
Hippodamia convergens · also called convergent lady beetles, convergent ladybird
A mountainside crevice holds what looks like a solid orange-and-black carpet, but a closer look reveals millions of individual convergent lady beetles packed together, an overwintering gathering so reliable that people travel specifically to collect and sell them.
Overview
The convergent lady beetle, Hippodamia convergens, is a native North American ladybird found in grassland and mountain habitat from Canada south through Mexico. Its distinctive converging head markings, massive mountain overwintering aggregations, and role as a commercially harvested natural pest predator make it one of the more ecologically and economically notable ladybirds on the continent.
A gathering millions strong
Few insects assemble in numbers as visually overwhelming as the convergent lady beetle’s mountain overwintering sites, where a single sheltered crevice can hold a population dense enough to be harvested by the handful.
Status
Least Concern — widespread and common across suitable grassland and mountain habitat throughout North America.
Convergent Lady Beetle: common questions
Why is it called the convergent lady beetle?
This species is named for two short white lines on the dark area just behind its head that angle toward each other, converging rather than running parallel, a distinguishing feature that helps separate it from several other native North American ladybird species.
Why do convergent lady beetles gather in such huge numbers?
Each autumn, this species migrates to specific mountain locations where individuals cluster together in aggregations that can number in the millions, a strategy that helps them conserve moisture and survive the winter before dispersing again in spring.
Is it a good idea to buy convergent lady beetles for garden pest control?
It's a mixed bag — these beetles are commercially collected from their enormous natural overwintering aggregations and sold as a natural aphid control method, but released beetles often disperse away from the release site fairly quickly, meaning the pest-control benefit can be shorter-lived than gardeners hope for.
Is the convergent lady beetle native to North America?
Yes, unlike some other commonly seen ladybird species that were deliberately introduced from other continents, the convergent lady beetle is native to North America, ranging naturally from Canada south through Mexico.