About Lygaeus kalmii Stal, 1874
This insect, commonly known as the small milkweed bug, has the scientific name Lygaeus kalmii Stal, 1874. Young nymphs are entirely red when they first hatch, and develop black diagonal markings on their pronotum as they mature. Adult small milkweed bugs range in color from orange to red mixed with gray or black, and grow to a length of 10 to 12 mm, or 0.39 to 0.47 inches. The head is black with a red spot at its center. The forewings have a distinct pattern: a black heart shape sits inside an orange-red X that does not meet at the middle. For the eastern subspecies Lygaeus kalmii angustomarginatus, the membranous section of the forewing has a narrow white margin. For the nominate western subspecies L. k. kalmii, the membranous forewing section has white spots and a broader margin. The small milkweed bug is often confused with other black and red or orange insects, specifically Oncopeltus fasciatus, Lygaeus turcicus, and Lygaeus reclivatus. The eastern subspecies Lygaeus kalmii angustomarginatus occurs in north temperate regions of North America, and it is non-migratory. Only adult individuals overwinter, and they do not start reproducing until the following April. Females are receptive to mating with males during all seasons. In spring, females lay their eggs on plants in the genus Asclepias, commonly known as milkweed.
