Soldier beetles | UMN Extension

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Quick facts

Large numbers of soldiers beetles may be seen in gardens in the summer.
Adults are active from late July to September.
Adult beetles are found on flowers and leaves of many plants, especially ones with yellow flowers such as goldenrod, helianthus, coneflower, tansy, zinnia, marigold and globe thistle.
They are harmless to plants and are beneficial as pollinators.
There is no need to control them. Just ignore them and they will go away on their own.

(Chauliognatha pennsylvanicus)

About ½ inch long, yellowish to tannish-brown with soft wing covers.
Black head, black legs with a black spot behind the head and an oval, black spot on each wing cover.
Wing covers do not completely cover the body, leaving abdominal segments exposed.
The head is clearly visible and they have chewing mouth parts.
Soldier beetles are related to fireflies but do not have the light-producing organs that fireflies have.

Adult soldier beetles are noticeable, but larvae are rarely seen.

Soldier beetles live through winter as larvae.
During spring they are active in leaf litter, plant debris, loose soil and other areas where high humidity occurs.
They mainly feed on insect eggs and larvae.
Larvae transform into pupae in early summer with adults first emerging in late July.
They are active through August and into September.
Adults will lay eggs some time at the end of the summer.
Larvae hatch from the eggs and they remain in this stage for the winter.
There is one generation a year.

Soldier beetles are very active and readily fly.
They look like wasps in flight.
They can also look like bees by moving quickly and often between flowers.
Because of their frequent contact with flowers, soldier beetles are important pollinators.
Soldier beetles are often seen mating on flowers.
Soldier beetles protect themselves by secreting defensive chemical compounds to make them a less attractive target for predators.
Their yellowish color is thought to signal that they don't taste good.

Soldier beetles mainly feed on pollen and nectar.
They do NOT damage flowers or other plants and are also harmless to people.
They are beneficial because they are predators (larvae) and pollinators (adults).
There is no need to control them. Just ignore them and they will go away on their own.

Jeffrey Hahn, Extension entomologist

Reviewed in 2018