Coccinellidae, or “ladybird beetles” are a family of beetles belonging to the superfamily Cucujoidea, with nearly 6,000 species known worldwide. 54 species are reported to occur in North Dakota. Some species are native, and others are adventive (having arrived from somewhere else). Among the adventive species, some were introduced and others are immigrants (having arrived by any means except deliberate introduction). In the USA, the name ladybird was americanized to ladybug, although these insects are beetles (Coleoptera), not bugs (Hemiptera).

Ladybird adults are oval in shape and range in length from 1 mm to over 10 mm with females on average larger than males. Adults are able to reflex-bleed from the tibio-femoral articulations (leg joints). The hemolymph has a repulsive smell, and in some species, contains toxins. The hemolymph is yellow in color and its repellency and toxicity are believed to be a defense mechanism against predators. the bright (red on black, or black on red) colors of some ladybirds may be aposematic, meaning the coloration warns would-be predators that the beetles are distasteful or toxic.

The majority of ladybird species are beneficial, feeding on aphids and a variety of other soft-bodied arthropods. The following images are based upon a faunal list completed by the North Dakota State University Department of Entomology in 2003. All images have been formatted to one standard size. Actual specimen length is provided in millimeters. click on an image for larger view.