Green Stink Bug

The Green Stink Bug (Chinavia hilaris) is a common agricultural pest native to North America. As its name suggests, when disturbed or crushed, it releases a disagreeable odor from scent glands located on the thorax.

Host Plants

The Green Stink Bug is a polyphagous insect, which means it can feed on a wide range of host plants. It is particularly damaging to agricultural crops such as soybean, corn, peas, tomatoes, peaches, and other fruits. It also feeds on a variety of weeds and tree species.

Regions impacted

Green Stink Bugs are widespread across North America and can be found throughout eastern North America, spanning from Quebec and New England to the Pacific Coast in the northern U.S. and southern Canada. It also occurs from Florida to California in the southwest region.

Description

Adult Green Stink Bugs are bright green and shield-shaped, measuring about 14-19 mm in length. They have fully developed wings, and their antennae are marked with alternating bands of dark and light colors. A key feature is the thin, double-edged yellow line bordering the sides of the abdomen, visible from a top view when the wings are folded.

The nymphs (immature stages) differ in appearance from the adults. They are smaller and wingless, and their color varies depending on age. Early instar nymphs are small and orange-red, and later instars are black and green with orange and white markings.

Life Cycle

Like other stink bugs, the Green Stink Bug undergoes a simple metamorphosis with three stages: egg, nymph, and adult.

• Egg: The life cycle starts when females lay clusters of barrel-shaped eggs, typically on the underside of leaves. The eggs are light green when first laid, turning pinkish as they near hatching.
• Nymph: The nymphs that hatch from these eggs go through five instar stages, growing larger and changing color with each stage.  They resemble adults in shape but are smaller and lack fully developed wings. Their color transforms as they grow. Early nymphs are typically orange or red, while older ones become black and green with distinct white and orange markings. . Young nymphs tend to stay close to the egg mass, but older nymphs will move away to feed. Nymphs
• Adult: After the final molt, the nymphs become adult stink bugs. Adults are strong fliers and will move to find new food sources or overwintering sites.

There are usually one to two generations of Green Stink Bugs per year, depending on the climate and length of the growing season.

Damage and Detection

Damage:

Green Stink Bugs are notorious for the extensive damage they can cause to a wide variety of crops. The primary damage is caused by their feeding activity, during which they pierce the plant tissues with their sharp, straw-like mouthparts to extract the plant’s sap.

Depending on the type of crop, the feeding activity can lead to different types of damage:

• Fruits and Vegetables: In fruits and vegetables such as tomatoes, peaches, and cherries, their feeding can cause depressions, discoloration, and deformities. Their punctures can lead to a condition known as “cat-facing,” where the fruit forms scar tissues that cause it to be distorted and unsightly, hence unmarketable.
• Cereals and Fibre Crops: In crops such as corn and cotton, the bugs’ feeding can lead to undeveloped kernels and reduced yield. Their feeding on cotton can cause a condition known as “stay-green,” where the plant stays green and fails to mature properly, affecting the cotton’s quality.
• Legumes: In legume crops such as soybeans, feeding by Green Stink Bugs can cause pod deformation and seed damage, leading to a reduction in yield and quality.

Detection:

Detecting Green Stink Bug infestations involves looking for signs of the bugs and their feeding damage. Here are some ways to detect these pests:

• Visual Inspection: Regular inspection of crops is vital. Look for the bugs on the plants, especially on the underside of leaves and around the fruit and seed pods.
• Feeding Damage: Look for signs of their feeding activity. This can include discoloration, deformities, or depressions on the fruit, as well as undeveloped seeds in legumes and cereal crops.
• Scent: If disturbed or crushed, these bugs emit an unpleasant smell. This distinct odor can sometimes be an indication of their presence.
• Egg masses: Female stink bugs lay clusters of eggs, typically on the underside of leaves. These eggs are barrel-shaped and initially light green, turning pinkish as they near hatching.

Overall, early detection and proper identification of Green Stink Bugs are crucial steps toward managing these pests effectively and minimizing the damage they cause.

Prevention and Control

Preventing and controlling the spread of Green Stink Bugs (Chinavia hilaris) involves a combination of cultural, biological, and chemical strategies.

Prevention:

• Crop Rotation: Regular rotation of crops can disrupt the life cycle of Green Stink Bugs and prevent large populations from establishing.
• Weed Control: Weeds can serve as alternative hosts for Green Stink Bugs. Keeping fields and surrounding areas free of weeds can help reduce potential habitats for these pests.
• Clean Cultivation: Plowing under crop residues can destroy the overwintering stages of the pest, reducing their numbers in the next growing season.
• Monitoring: Regular inspection and monitoring of fields can help detect infestations in the early stages, allowing for prompt and effective intervention.

Control:

• Biological Control: Several natural enemies can help control Green Stink Bug populations. These include parasitic wasps, such as Trissolcus spp., and predatory insects, like the Spined Soldier Bug (Podisus maculiventris). Birds, toads, spiders, other insect-eating animals prey on them. Encouraging these natural enemies, for example by planting habitats for them or avoiding unnecessary pesticide use, can be an effective part of integrated pest management.
• Trap Crops: Some farmers plant trap crops that are more attractive to the stink bugs than their primary crop. Examples of trap crops include sorghum, millet, buckwheat, or sunflower. Once the bugs have aggregated on the trap crop, they can be treated with an insecticide to eliminate them.
• Pheromone Traps: These traps, baited with a substance that mimics the scent of the female stink bug, can attract and capture male stink bugs, helping to reduce their populations.
• Insecticides: In cases of severe infestations, insecticides may be necessary. It is crucial to use these products judiciously and follow label instructions to minimize harm to beneficial insects and prevent the development of pesticide resistance in the pest population.

In conclusion, the most effective strategy for controlling Green Stink Bugs is an integrated pest management (IPM) approach, combining preventive practices, monitoring, biological controls, and chemical controls when necessary. This approach helps to minimize pesticide use and ensure long-term, sustainable pest management.