Bug FAQBrown soldier bug
Cermatulus nasalis · Order: Hemiptera · Family: Pentatomidae
Female brown soldier bugs are about 10.5 to 12.5 mm long; males are a bit smaller. They have a brown head with a rounded snout, a triangular prothorax with yellow-orange-rusty markings, black dorsal abdomen, mottled yellow-brown ventral abdomen, brown forewings with a large black triangle, and yellow-brown antennae and legs. They are predatory shield bugs that stab insects with their beak and suck out fluids; nymphs start red with black heads and feed on egg-coating bacteria and plant sap.
Source: Wikipedia
How to recognize it
Head brown with rounded snout; prothorax triangular with yellow-orange-rusty brown and black markings; abdomen black on top, mottled yellow-brown underneath; forewings brown with a large black triangle; antennae and legs yellow-brown.
Source: Wikipedia
Size
Females 10.5 to 12.5 mm long; males slightly smaller.
Source: Wikipedia
Where it lives
They are predatory insects that hunt other insects.
Source: Wikipedia
Life cycle
One generation per year, breeding in summer for several weeks; they molt five times, each instar showing different red and black patterns.
Source: Wikipedia
When you see it
Breeding occurs over several weeks during the summer.
Source: Wikipedia
Lookalikes
It is a predatory shield bug in the family Pentatomidae.
Source: Wikipedia
More photos
Questions people ask
What do brown soldier bugs look like?
They have a brown head with a rounded snout, a triangular yellow-orange-rusty prothorax with black markings, a black dorsal abdomen, mottled yellow-brown ventral abdomen, brown forewings with a large black triangle, and yellow-brown antennae and legs.
Source: Wikipedia
What do they eat?
Adults prey on various insects, using their beak to suck body fluids; young nymphs start red with black heads and feed on egg-coating bacteria and plant sap.
Source: Wikipedia
When are they active?
They breed during the summer months, with one generation per year.
Source: Wikipedia
Same family (Pentatomidae)
Brown Marmorated Stink BugHalyomorpha halysDamages trees, gardens or crops
Green Stink BugChinavia hilarisDamages trees, gardens or crops
Harlequin BugMurgantia histrionicaDamages trees, gardens or crops
Brown Stink BugEuschistus servusDamages trees, gardens or crops
Green Shield BugPalomena prasina
European Striped Shield BugGraphosoma italicumSources
- Wikipedia: https://en.wikipedia.org/wiki/Cermatulus_nasalis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.