The ten-lined June beetle (Polyphylla decemlineata), also known as the watermelon beetle, is a scarab beetle found in the western United States and Canada. The adults are attracted to light and feed on foliage. They can make a hissing sound when touched or otherwise disturbed, which can resemble the hissing of a bat. This sound is made by their wings pushing down, forcing the air out between their wings and back. They can be an agricultural pest affecting a wide range of crops because their larvae feed on plant roots and can weaken or kill the plants.

They are relatively large in size, some growing to sizes as large as 1.5 inches (3 cm) or more. As in other members of this genus, the males have large distinctive antennae consisting of several lamellate plates, which they close up when threatened. The antennae are used to detect pheromones emitted by the females.  The wing covers (elytra) have four long white stripes and one short stripe each. The underside of the thorax is covered with brownish hairs.

Description

Eggs: The eggs are oval, dull, and creamy. They are about 1/16 of an inch long.
Larva: The grub can grow up to 2 inches with 3 pairs of legs, with a white body and brown head. The larval stage can last as long as 4 years.

Life cycle

harmful

bite

Polyphylla decemlineata, commonly known as the ten-lined June beetle, is considered a tree pest because its larvae feed on the roots of various trees, causing damage and potentially leading to tree decline or death.

tree pest

Polyphylla decemlineata can be considered garden pests because their larvae feed on the roots of various plants, including those commonly found in gardens, leading to damage and potential loss of plants.

garden pest

Polyphylla decemlineata can be considered crop pests because their larvae feed on the roots of various crops, such as potatoes, causing damage and reducing crop yield.

crop pest

Polyphylla decemlineata is considered a pest because its larvae feed on the roots of trees, plants, and crops, causing damage and potentially leading to decline or loss of vegetation, which can have negative impacts on ecosystems, agriculture, and horticulture.

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Are ten-lined June beetle harmful to humans?

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