Small milkweed bug
Lygaeus kalmii
Smaller, redder, and far less fussy than its large cousin: it takes seed, nectar and the occasional dead insect.
What it does on milkweed
Small milkweed bugs feed mainly on milkweed seed but will also take nectar and scavenge dead insects, including ones that died trapped in milkweed flowers. That flexibility lets them appear earlier in the season than the large milkweed bug, before there is any seed to eat. They overwinter as adults in leaf litter.
How to recognize it
About 10 to 12 mm. Black with a red X shape across the folded wings, formed by a red band across the front and a red stripe down each side, and two small white spots at the wing tips.
Where and when
Throughout the United States, including the arid West. Most often seen April to October.
Should you do anything about it?
Leave them alone. They take a small share of seed and eat some of the insects that die on the flowers.
Small milkweed bug: common questions
What is the difference between large and small milkweed bugs?
The large milkweed bug has a solid black band across an orange back. The small milkweed bug is black with a red X. The small one is also the earlier of the two to appear.
Cite this page
This page is licensed CC BY 4.0. Quote it, adapt it and reuse it, including commercially, as long as you credit Milkweed USA and link back.
Milkweed USA. (2026). Small milkweed bug (Lygaeus kalmii). Retrieved DATE, from https://milkweedusa.com/wildlife/small-milkweed-bug/
"Small milkweed bug (Lygaeus kalmii)." Milkweed USA, 2026, https://milkweedusa.com/wildlife/small-milkweed-bug/. Accessed DATE.
Milkweed USA. "Small milkweed bug (Lygaeus kalmii)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/wildlife/small-milkweed-bug/.
@misc{milkweedusa_wildlifesmallmilkweedbug,
title = {Small milkweed bug (Lygaeus kalmii)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/wildlife/small-milkweed-bug/},
note = {Accessed DATE}
}