**Green Stink Bugs** (*Chinavia hilaris*, formerly *Acrosternum hilare*) are large, shield-shaped insects found throughout North and Central America. They are one of the most economically important species in the stink bug family (Pentatomidae) due to their wide host range, which includes many high-value agricultural crops, particularly **soybeans, corn, tomatoes, and peaches**. They cause damage by piercing plant tissues with their mouthparts to suck out the sap and developing seeds, and they are notorious for emitting a noxious odor when disturbed.
Taxonomy and Classification
Green Stink Bugs belong to the order Hemiptera (true bugs). They undergo incomplete metamorphosis (egg, nymph, adult). They are closely related to the Brown Marmorated Stink Bug (BMSB) and other agricultural pests. Their family name, Pentatomidae, derives from the five-sided, shield-like shape of their bodies.
Physical Description
Adult Green Stink Bugs are large, $1/2$ to $3/4$ inch long, and broad.
- **Appearance:** Bright, uniformly emerald green, with a distinct triangular or shield-like shape.
- **Odor:** Possess specialized thoracic glands that release a foul-smelling, defensive chemical (aldehyde-based) when the bug is squeezed or disturbed.
- **Nymphs:** Younger stages (nymphs) are often brightly colored, having black, red, and green markings, but lack the full shield shape.
Distribution and Habitat
Green Stink Bugs are widespread across the Americas. Their habitat includes native host plants (weeds, trees) but they are primarily found in cultivated agricultural fields, orchards, and vegetable gardens. They overwinter as adults in leaf litter, under bark, or other protected areas, emerging in spring to feed and reproduce.
Behavior and Damage
Stink Bugs feed using a long, needle-like proboscis to pierce tissues, targeting the most nutrient-rich parts of the plant.
- **Fruit/Vegetable Damage:** Feeding on peaches, apples, and tomatoes causes hard, brown, necrotic spots and dimpling, known as **”catfacing”** or corking, severely reducing the market quality.
- **Seed Damage (Soybeans/Corn):** Feeding on developing soybean pods or corn kernels causes shriveling, discoloration, and reduced seed weight and quality, often resulting in economic loss.
- **Nuisance:** They are an occasional nuisance in homes when seeking overwintering shelter in the fall, though they do not reproduce indoors.
Management and Prevention
Control focuses on monitoring and targeted chemical intervention.
- **Monitoring:** Use sweep nets in field crops and visual inspection in orchards to determine population thresholds before applying treatments.
- **Habitat Management:** Eliminate dense, tall weed growth and wild host plants near crops, especially early in the season, to reduce initial population sources.
- **Trap Crops:** Planting a highly preferred “trap crop” (e.g., specific weed species or an early-maturing crop variety) that attracts the bugs before they move to the main crop can allow for targeted insecticide application on a small area.
- **Chemical Control:** Control relies on scouting and applying broad-spectrum insecticides or targeted organic sprays (e.g., pyrethrin) when populations exceed economic thresholds.
Conservation and Research
Green Stink Bugs are managed as persistent agricultural pests. Research focuses on exploiting their chemical ecology (pheromones) to improve trap designs, and increasing the effectiveness of natural enemies, such as the parasitic **Tachinid flies** and **scelionid wasps** that attack the eggs.