The ten-lined June beetle (''Polyphylla decemlineata''), also known as the watermelon beetle, is a

scarab beetle The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change in recent years. Several sub ...

found in the western United States and Canada. The adults are attracted to light and feed on

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

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

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". 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 ...

. 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 (; ; , ) 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 (sometimes alterna ...

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

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