Hosts or Prey
Caterpillars, larvae of beetles, and other slow-moving, soft-bodied insects, such as sawflies
Identification
Adults are shield shaped and about 2/5 inch (10 mm) long. They are black with a contrasting color that varies among individuals: commonly reddish orange, pale green, white, or yellowish. On the first segment immediately behind the head (prothorax) are two black markings, the two spots for which the species is named. Adult stink bugs are distinguished from other insects by the large triangle shape with a rounded rear end (scutellum) that occurs on top and covers the third thoracic segment and front portion of the abdomen. On twospotted stink bugs the margins of the scutellum color contrast with adjacent markings.
The barrel-shaped eggs are about 1/20 inch (1.2 mm) in diameter and occur in clusters. Eggs are green when laid and turn blackish before hatching. A ring of spines surrounds the top margin, projections that are shorter in comparison with those of eggs of the spined soldier bug that also is a beneficial predator.
Nymphs are round to oval shaped. First instars are about 1/16 inch (1.5 mm) long. Last (fifth) instars are about 1/3 inch (8 mm) long. First and second instars have a black head and thorax and a mostly red abdomen, resembling first instars of the spined soldier bug. The third through fifth instars are black with white and orange, red, reddish orange, or reddish yellow. Wing pads (developing wings) are obvious in the last two instars.
Life Cycle
Stink bugs develop through 3 life stages: egg, nymph, and adult. An adult female can lay about 200 eggs. Eggs hatch about 1 week after being laid. First instars at least initially remain together by their empty egg cases and they feed mostly by sucking plant juices. Later instars become more active and are predaceous.
Somewhat commonly more than one twospotted stink bug can be observed feeding on the same prey. Adults and nymphs suck and feed on prey using their tubular mouthparts, which they can extend forward in front of the body. This differs from plant-feeding stink bugs where the mouthparts point downward when feeding. Both plant-feeding and predaceous stink bugs can fold their mouthparts backwards underneath the body.
During its development, a twospotted stink bug nymph can consume 300 to 400 leaf beetle eggs. Adults can consume about 80 leaf beetle larvae during their approximately 6 week life span.
In mild winter locations, twospotted stink bugs can be active throughout the year. Where winters are cold, overwintering is as adults in protected places, such as crevices of bark or in organic litter or other debris on the ground.
Egg to adult development is about 1 month during the growing season. There are several generations per year in California.
Habitat
Adults and nymphs can occur in virtually any crop and in gardens, landscapes, and wildlands. They have been recorded feeding on over 40 species of pest insects.
To improve biological control
- Control ants because they attack natural enemies.
- Grow flowering insectary plants to provide nectar and pollen to feed adult natural enemies.
- Reduce dustiness that disrupts the activities of natural enemies (e.g., periodically hose off small plants).
- Avoid the application of broad-spectrum, persistent insecticides for all pests because they are toxic to natural enemies.
See Protecting Natural Enemies and Pollinators for more information.
Species
At least 50 species of stink bugs occur in California. Most are plant feeders and some of these are significant pests. See Stink Bugs to distinguish some common pest species. Predaceous stink bugs include Brochymena, Perillus, and Podisus species, such as rough stink bugs and the spined soldier bug.
More Information
- Species Perillus bioculatus - Two-spotted Stink Bug, BugGuide, University of Iowa
- Two Spotted Stink Bug Hemiptera: Pentatomidae Perillus bioculatus (PDF), Oregon State University
- Two-spotted Stink Bug, Perillus bioculatus (Fabricius) (Hemiptera: Pentatomidae: Asopinae), Encyclopedia of Entomology
Scientific classification:
- Phylum: Arthropoda
- Class: Insecta
- Order: Heteroptera
- Family: Pentatomidae
