Ladybugs (family Coccinellidae) are recognizable insects cherished for their beneficial appetite for garden pests. While often viewed with affection, the question of whether they are endangered is complicated. The conservation status of ladybugs is not uniform across the entire family; it depends highly on the specific species and geographical area. While some species are abundant, many native species in North America are experiencing a significant decline.
Conservation Status Varies by Species
Ladybug populations consist of two groups: thriving introduced species and struggling native ones. Non-native ladybugs, such as the Multicolored Asian Lady Beetle (Harmonia axyridis), are flourishing and often overabundant across the continent. These introduced species are the beetles most commonly encountered by the public, sometimes becoming household nuisances during fall overwintering.
Many native North American species have seen severe population reductions since the latter half of the 20th century. For example, the Nine-spotted Ladybug (Coccinella novemnotata) was once common across the United States and Canada, but its numbers rapidly declined starting in the 1980s. This beetle is now extremely rare throughout its historical range. Due to this severe reduction in range, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) listed it as endangered.
Ecological Role and Drivers of Native Decline
Native ladybugs play a fundamental role in ecosystems as natural predators of soft-bodied insects like aphids, scale insects, and mites. A single ladybug can consume dozens of aphids daily, making them effective biological control agents in agricultural and natural settings. This predatory function helps maintain ecological balance and reduces the need for chemical pest control.
The decline of native populations stems from three major interconnected threats. First is the widespread use of broad-spectrum pesticides, which eliminate ladybugs along with pests. Second, habitat loss and fragmentation reduce the availability of diverse native plants ladybugs rely on for shelter, mating, and supplemental food sources like pollen and nectar.
Third, the introduction of non-native species, such as the Asian Lady Beetle and the Seven-spotted Lady Beetle (Coccinella septempunctata), presents a major challenge. These introduced beetles aggressively compete with native species for limited food resources, especially aphids. Invasive species also engage in intraguild predation, actively eating the eggs, larvae, and pupae of native ladybugs. Introduced ladybugs can also carry parasitic fungi that harm native populations when transmitted.
Identifying Native Versus Introduced Ladybugs
Distinguishing between native and introduced ladybugs is important for citizen science efforts tracking native species decline. The Multicolored Asian Lady Beetle (Harmonia axyridis) is the most commonly mistaken invasive species. It can be identified by a distinct marking on its pronotum, the shield-like segment behind its head. This marking is a visible black shape that looks like an “M” or a “W” depending on the viewing angle.
The Asian Lady Beetle’s physical appearance is highly variable, with colors ranging from pale orange to dark red and a spot count from zero up to 22. In contrast, many struggling native species, like the Nine-spotted Ladybug, have a more consistent pattern of four spots on each wing cover and one split spot in the center. A key behavioral difference is that non-native Asian Lady Beetles frequently seek shelter indoors during the fall for overwintering, while native ladybugs generally hibernate outdoors in leaf litter or under rocks.
How to Support Native Ladybug Populations
Individuals can take several simple steps to help conserve native ladybugs in their gardens and communities. Completely eliminating or significantly reducing the use of insecticides, especially systemic products like neonicotinoids, prevents the direct poisoning of adult ladybugs and their larval stage. Since ladybugs are attracted to areas with prey, tolerating small populations of aphids provides a necessary food source for the beetles to establish and reproduce.
Creating a diverse and hospitable habitat is also beneficial. Planting native flowers that provide pollen and nectar, such as dill, yarrow, and fennel, offers supplemental nutrition when insect prey is scarce. Leaving leaf litter, brush piles, or dead wood in garden areas provides safe, cool, and moist locations for native ladybugs to overwinter. People can also contribute valuable data to conservation research by participating in citizen science initiatives, such as the Lost Ladybug Project, which tracks rare native species across the continent.