Shield bugs, commonly known as stink bugs, are insects recognized by their distinctive shield-like shape. While generally not a direct threat to humans or household pets, they can become a nuisance indoors and cause considerable damage to agricultural crops.
Risk to Humans and Pets
Shield bugs do not bite or sting humans or pets. Their mouthparts are designed for piercing and sucking plant fluids, not for biting skin or drawing blood. They do not carry diseases transmissible to humans or animals. Their primary defense mechanism involves releasing a foul-smelling odor when threatened or crushed.
This odor is unpleasant but generally not toxic. In very rare instances, the fluid can cause mild skin irritation or eye irritation, necessitating thorough rinsing. For pets, ingesting shield bugs can lead to gastrointestinal upset, though these symptoms typically resolve on their own. In extremely rare cases, consuming a large quantity of bugs can form a mass in the pet’s stomach requiring veterinary intervention.
Impact on Plants and Agriculture
Shield bugs can cause extensive damage to a wide range of plants, making them significant agricultural pests. These insects possess piercing-sucking mouthparts, which they use to inject enzymes into plant tissues and then extract plant sap. This feeding behavior can lead to plant injury and economic loss.
Damage symptoms include stunted growth, deformities, and reduced yields. On fruits, their feeding can cause discoloration, pitting, and a mealy texture, often rendering the produce unmarketable. For instance, tomatoes may develop “cloudy spot” and peaches can show water-soaked lesions. Shield bugs feed on a broad spectrum of plants, including fruit trees like apples, peaches, and plums, as well as vegetables such as corn, beans, tomatoes, and peppers. They also affect ornamental plants and can facilitate the spread of plant diseases, impacting crop health and resulting in substantial economic losses for farmers.
Safe Management and Prevention
Managing shield bugs, whether indoors or in crops, focuses on non-toxic and environmentally conscious methods. To prevent them from entering homes, seal entry points like cracks around windows, doors, and utility pipes, and ensure screens are intact. Removing outdoor clutter like leaf litter and weeds can also reduce overwintering sites near the home.
For bugs already inside, physical removal is a common method. Hand-picking them and dropping them into soapy water is effective, causing them to drown. Vacuuming can also remove large numbers, but the vacuum bag should be emptied outdoors immediately to prevent odor release. In gardens, maintaining cleanliness by removing plant debris and practicing crop rotation helps deter shield bugs. Planting deterrents like garlic, mint, or chrysanthemums, and encouraging beneficial insects like parasitic wasps, can help control populations.