Transverse Lady Beetle | NWT Species at Risk

Transverse Lady Beetle

Coccinella transversoguttata

NWT List of Species at Risk:

No status

NWT SARC Assessment:

Not assessed

Federal Species at Risk Act list:

Special Concern

COSEWIC Assessment:

Special Concern

NWT General Status Rank:

Secure

Description:

Transverse Lady Beetle is a small, round beetle that can be distinguished from other lady beetles by its colour pattern. Its wing covers are red to orange with black markings: a ‘transverse’ black band across the front and four elongated black spots toward the back. The head is black with two separate pale spots. The plate behind the head is also black with pale markings on either side.

Adult length: 5.0 to 7.8 mm (0.20 to 0.31 in).

Report Transverse Lady Beetle sightings to WILDLIFEOBS@gov.nt.ca

Check out the Field Guide to Lady Beetles of the Northwest Territories

Distribution

Range map information

Habitat and biology

Transverse Lady Beetles use a wide range of habitats and are found on a variety of plants. They move around to take advantage of available prey (aphids and other insects). When Transverse Lady Beetle was common, it played an important role in the biological control of aphids and other "pests" of gardens and crops.

There are 32 native lady beetle species in the NWT and one introduced species. Three other native species are expected to be present but not yet confirmed. NWT residents submitting photos to the NWT Species Facebook page have helped scientists to learn about lady beetles in Canada.

Population size and trends

Historically, Transverse Lady Beetle was found across Canada and was one of the most common lady beetle species. However, since 1986 it has undergone population declines. In many areas where it was once common it is now absent, below detection limits, or at low numbers. Reasons for the population declines are unclear but introduced non-native lady beetles are probably an important factor that has brought increased competition and predation, as well as new diseases and parasites. Pesticide use may also be a factor.

Transverse Lady Beetle is still common in the NWT, Yukon and British Columbia where there are fewer non-native lady beetle species.

Threats

Potential threats in the Northwest Territories include negative interactions with non-native species such as Seven-spotted Lady Beetle, and use of pesticides.

Protection and recovery

COSEWIC assessed Transverse Lady Beetle as Special Concern in Canada in 2016 because of population decline and threats. It was listed as Special Concern under the federal Species at Risk Act (SARA) in 2021.

Area:

Dehcho, Gwich'in, Inuvialuit, Sahtú, South Slave, North Slave / Tłı̨chǫ

Links:

Field Guide to Lady Beetles of the Northwest Territories