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 A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, f ...

. They can make a hissing sound when touched or otherwise disturbed, which can resemble the hissing of a

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

. 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.

Description

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 An elytron (; ; : elytra, ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometime ...

) have four long white stripes and one short stripe each. The underside of the thorax is covered with brownish hairs.

Identification

This species is commonly confused with ''Polyphylla Critina'', also known as the Long Haired June Beetle. ''Polyphylla Decemlineata'', or the ten-lined June beetle, has

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

on the protonum. The Long Haired June beetle (''Polyphylla Critina'') instead has

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

(hair) on the protonum. Due to this difference, these species require high resolution photos for differentiation between the two.

Life cycle

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. Polyphylla decemlineata MHNT femelle dos.jpg, Dorsal side ♀ Polyphylla decemlineata MHNT femelle ventre.jpg, Ventral side ♀ Ten Lined June Beetle.JPG, Ten Lined June Beetle ♂ Ten Lined June Beetle - Open.JPG, Ten Lined June Beetle - Open ♂ Polyphylla decemlineata morning stretches 2016-05-27.webm, Coming back to life after a cool night

References

External links

Wayne's Word page on beetles

The Daily Garden - Ten-lined June Beetle
{{Taxonbar, from=Q2378176 Beetles of North America Polyphylla Beetles described in 1823