The Spined Soldier Bug

Over the past three years in our Colorado potato beetle (CPB) biocontrol trials at the UVM Horticultural Research and Education Center, one visitor kept showing up again and again: the spined soldier bug (Podisus maculiventris, family Pentatomidae, subfamily Asopinae).

Egg Cluster

18 eggs, each topped with its spiny crown.

Eggs

Laid in tight clusters of 17–70, each egg comes crowned with a spiny “helmet.” Depending on temperature, eggs hatch in 5–9 days.

Nymph Stage

Fourth-instar of a predatory stink bug.

Nymphs

Early instars start out with black heads and bright red abdomens. As they molt, they develop striking mottled patterns of red, white, and black. Young nymphs stick together in little squads, but by the 3rd or 4th molt they disperse to hunt solo.

Under summer conditions, nymphs develop into adults in 22–29 days.

Adult

Predatory adult attacking a beetle larva.

Adults

Around 11 mm long, adults are mottled brown and unmistakable with their shoulder spines. In northern regions, they hibernate through winter; farther south, they stay active year-round. Adults live 1–4 months, sometimes longer in mild conditions.

Why They Matter

Spined soldier bugs aren’t just wild allies—they’re also reared and sold commercially as biocontrol agents. They’ve even been introduced overseas to help manage leaf-feeding pests in vegetable and field crops. In our potato plots, we’ve found them again and again across years and treatments. Their presence reminds us that if we create the right habitat—like strips of flowering buckwheat to provide nectar and cover—we can support these natural guardians.