Lady Bug ID: Native vs Asian Lady Beetles and Look-Alikes

To ID a ladybug, look first at the white plate directly behind the head (the pronotum), then count the spots. A black M or W on that plate means the multicolored Asian lady beetle; two thin white lines that converge toward the centre mean the native convergent lady beetle; exactly seven black spots on deep red mean the seven-spotted lady beetle (Nature's Good Guys; Penn State Extension).

• The plate behind the head. Penn State Extension describes the Asian lady beetle's pronotum as white with a black W, which may be filled in as a solid patch; from the other direction it reads as an M.
• The spots. Count them, but do not rely on them alone. Asian lady beetles range from no spots to 18 on red, or come in a black form with 2 to 12 orange or red spots (Penn State Extension). A seven-spotted has seven.
• Shape and size. Asian lady beetles are about 7 mm long, oval and convex (Penn State Extension). Nature's Good Guys describes the convergent as smaller and more elongated and the seven-spotted as noticeably larger and rounder.

Most ladybugs people find in the United States are either the multicolored Asian lady beetle, the one that comes indoors in autumn, or one of the red-and-black garden species such as the convergent and seven-spotted lady beetles.

• Multicolored Asian lady beetle (Harmonia axyridis): pale yellow to deep red, with anything from no spots to many (Nature's Good Guys gives 0 to 22, Penn State Extension up to 18). Its reliable mark is the black M or W behind the head.
• Convergent lady beetle (Hippodamia convergens): native; orange to brick red; spots from none to 12 or more; the two converging white lines behind the head give it its name (Nature's Good Guys).
• Seven-spotted lady beetle (Coccinella septempunctata): deep red with exactly seven spots and a white collar-like mark near the front (Nature's Good Guys).

They are the same insects: the beetle family Coccinellidae, with more than 6,000 described species from 0.8 to 18 mm long. "Ladybug" is the usual North American name and "ladybird" the British one; entomologists prefer "lady beetle" or "ladybird beetle" because these insects are beetles, not true bugs (Wikipedia).

• Mexican bean beetle: it is a lady beetle, but one of the few in North America that eats plants instead of insects. It is 6 to 7 mm, red to rusty brown to golden yellow, with eight black spots on each wing cover (16 in all). Its yellow, spiny larvae and the adults skeletonise bean leaves from underneath (Wikipedia).
• Carpet beetles: rounded, with short antennae, resembling small lady beetles but much smaller; see orange and black bugs for how to tell them apart.
• Ladybug larvae: people often do not recognise them as ladybugs at all. They are elongated with square heads, covered in hairs, and grey, blue-grey or brown spotted with white, yellow, red or orange (Wikipedia).

A quick check for a real lady beetle: large compound eyes and short clubbed antennae (Wikipedia), a rounded, domed shell, and wing covers that meet in a straight line like any beetle.

The easiest way to tell a native ladybug from the invasive Asian lady beetle is the black M or W on the white plate behind the head, which native species do not have (Nature's Good Guys). Behaviour is the second clue. Penn State Extension says Asian lady beetles start gathering on and in homes around the beginning of October, sometimes in the tens of thousands in attics and wall voids, and move into living areas because of the warmth. They occasionally bite, from slightly annoying to painful; they release a smelly yellow fluid from their leg joints that can spot walls; and rhinoconjunctivitis, asthma and facial swelling have been linked to heavy infestations. Anyone with breathing symptoms or swelling should see a doctor.

Outdoors they are good: lady beetles, both adults and larvae, are among the main natural enemies of aphids (UC IPM). Indoors the multicolored Asian lady beetle is a nuisance rather than a structural pest. Penn State Extension's advice is to seal them out with caulk and screening and, once they are inside, to vacuum them up, which it calls the most efficient method of removal.

Photograph it from directly above so the white plate behind the head is sharp; that one feature separates the Asian lady beetle from the natives. Take a second photo showing all the spots. InsectLens names the species from the photo.

Research and drafting for this page used AI assistance. Every figure, date and quotation was then checked line by line against the sources listed at the bottom of the page, each of which was opened while writing. Nothing here is a diagnosis. If a bite, sting or contact with an insect is followed by trouble breathing, swelling of the face or throat, spreading redness, fever or any symptom that worries you, get medical care; in the United States Poison Help (1-800-222-1222) is free and open 24 hours a day.

A lady beetle is dome-shaped on top, flat underneath and round when seen from above, with hard, shiny wing covers; UC IPM describes the seven-spotted lady beetle exactly this way, at almost 1/3 inch (8 mm) long and about 1/6 inch (4 mm) wide. Several insects share the colours but not this shape; the look-alikes are listed on this page above; for true bugs that are sometimes mistaken for beetles, see true bugs.

Many people find ladybug young and do not recognise them. UC IPM describes the stages of the two most common species:

• Seven-spotted lady beetle: eggs spindle-shaped, orange or yellowish, about 1 mm long, standing on end in clusters of about 10 to 30. Larvae look like tiny alligators, blackish, dark brown or dark grey with orange or yellowish spots, growing through four stages to about 8 mm. Pupae are about 6 mm, orange at first and gaining black blotches before the adult emerges. Egg to adult takes about six weeks, with up to five generations a year; adults live about two months in the growing season.
• Multicolored Asian lady beetle: eggs bright yellow, oblong, about 1.5 mm, in clusters of about 20 on the undersides of leaves. Larvae are also alligator-like, mostly black to dark bluish-grey with raised bumps and branched spines, and bright yellow-orange on top of abdominal segments 1 to 5; they reach about 8 mm. Egg to adult takes about 3 to 6 weeks, with up to six generations a year.

The orange stripe along the back of the larva is the quickest way to spot an Asian lady beetle before it becomes an adult.

The Asian lady beetle is the one that confuses people most, because it comes in so many forms. UC IPM describes adults as yellowish-orange to red with no spots or 18 or 19 black spots of varying size, about 6 mm long and 5 mm wide; deep orange with prominent spots is the most common form in California. Nature's Good Guys gives a range of zero to 22 spots. The constant is the white border around the plate behind the head, which usually outlines a black M or W (UC IPM).

When disturbed, adults release drops of odorous orange blood, which is what leaves stains and a smell indoors; UC IPM adds that they can taint grape and wine juice with their bitter blood.

UC IPM says commercially sold convergent lady beetles (*Hippodamia convergens*) may give some temporary aphid control when properly handled. Its example for one heavily infested rose bush is about 1,500 lady beetles per release, in two releases a week apart. Expect the effect to be short-lived, and check first that aphids, not another pest, are the problem.