The Grapevine Beetle (Pelidnota punctata) is a common, large insect found in North America, particularly near vineyards, gardens, and wooded areas. Belonging to the scarab family, it is sometimes called the spotted pelidnota or spotted June beetle. Because of its size, people often wonder about its threat level to humans or pets. This article addresses their behavior and the risk they pose to residential landscapes.
The Direct Answer: Do Grapevine Beetles Bite?
Grapevine beetles do not bite humans or other animals, and they are not considered dangerous. They are non-aggressive insects that typically try to escape or remain still when approached, rather than engaging in confrontation. The structure of their mouthparts, known as mandibles, is designed for chewing tough plant material, not for piercing skin.
These beetles are generally considered harmless to people. Although they have strong mouthparts for consuming leaves, they lack the anatomy necessary to inflict a defensive bite. If handled roughly, a large beetle might attempt to pinch with its legs or mouthparts, but this is a clumsy, defensive reflex, not a true venomous bite.
Identifying the Grapevine Beetle
Confirming the identity of Pelidnota punctata helps ease concern. The adult beetle is relatively large, typically measuring between 0.98 and 1.18 inches (25 to 30 mm) in length. Its body is stout and oval-shaped, colored a shiny yellowish-tan or reddish-brown.
The beetle is easily recognizable by the distinct black spots on its body. It usually has three black spots near the outer edge of each hardened wing cover (elytra), and often one spot on each side of the plate covering the thorax. Grapevine beetles are largely nocturnal, meaning they are most active at night, and are often found near outdoor lights.
Understanding Their Damage to Plants
While Grapevine Beetles do not pose a threat to humans, they are considered an agricultural pest due to their feeding habits. As their name suggests, their primary diet consists of the leaves of grapevines, including both wild and cultivated varieties. They also feed on the foliage of other plants, such as Virginia creeper and occasionally fruit trees.
The adults cause damage by skeletonizing leaves; they chew the tissue between the veins, leaving behind a lace-like pattern. They may also feed on ripe grapes and other fruits, but they rarely appear in large enough numbers to cause severe damage to an established plant. The larval stage, a C-shaped grub, lives underground for up to two years, feeding on decaying wood and organic matter, not the roots of living plants.