Description

Cotinis nitida, the green June beetle, is a bright green member of the subfamily Cetoniinae in the large beetle family Scarabaeidae. Dorsal surfaces of adults are green metallic with variable brown to brownish-yellow markings, especially along the margins of the wing covers (elytra). The ventral surface of the thorax is predominantly brownish yellow, while the ventral surface of the abdomen ranges from shiny metallic green to dark brown. Body length varies from 22 mm to 26 mm. The body is widest at the midpoint and tapers towards a small, narrow head, that bears a short, blunt horn on the face (clypeus) just above the mouthparts. The antennae are clubbed, consisting of a series of enlarged, overlapping segments (lamellate antennae) typical of the family.

Eggs are white and just under 2 mm in length. Each egg is enclosed in a small earthen cell. Up to 30 eggs may be deposited adjacent to each other.

Larvae are creamy white grubs with obvious body segmentation. The rear end is rounded and the head is broad, round and orange-brown colored. Each of the three segments of the larval thorax bears a pair of legs. Mature larvae may reach two inches in length. When at rest, the grubs assume a classic C-shape, typical of many scarab larvae, but when unearthed, they may straighten out and crawl caterpillar-like, dorsal side down, legs in the air.

Pupae are enclosed in a hard, earthen cocoon-like cases underground and resemble a soft, pale, rudimentary version of the adult.

Green June beetle is one of five species of the genus Cotinis in the U.S. It is the only common, widespread species in the eastern half of the country. A similar species, the figeater beetle (Cotinis mutabilis), is widespread in southwestern U.S. and into Mexico. The ranges of the two species overlap in central Texas. These two species are variable in color, especially the figeater beetle, and distinguishing them can be challenging. Positive identification requires dissecting the aedeagus (male sex organ) to examine small differences in anatomy. Distribution is useful in most cases, with eastern specimens representing Cotinis nitida and western specimens C. mutabilis.

Life Cycle

The green June beetle, Cotinis nitida, is holometabolous, like other beetles, with development occurring in four stages: egg, larva, pupa and adult. Adult green June beetles mate during July and August. Shortly after, females lay eggs in clusters of 10 to 30 in moist soil rich in organic matter. After about two weeks, larvae (grubs) emerge from the eggs and begin feeding. Larvae are omnivorous and feed on plant roots and decaying organic matter, including dead insects. Small larvae feed underground and larger, more mature larvae feed on the surface at night. They undergo three growth periods (instars) and can overwinter as third instars. Overwintering larvae prepare protective cases of salivary secretions and soil in preparation for colder temperatures. During spring, larvae become active and begin feeding again. Then they pupate in a rigid underground case of secretions and soil. After two or three weeks, adults emerge. Adults are strong flyers and are typically active during daytime. Mating is conducted on the ground. Adults can live up to several months and into the late fall in the south. They feed on fresh and decaying fruit as well as nutrient rich plant exudates.

Ecological Significance

Green June beetles are abundant across the eastern and southern United States. Adults are common seasonal insects in residential lawns, forest edges and overgrown fields and prairies. Larvae are members of the white grub complex of root-feeding scarabs and may damage turfgrass and residential lawns. Large populations of adults may damage fruit bearing trees, berries and grape crops by direct feeding and fouling fruit with body secretions. Overall, the green June beetle is not considered a major pest of agricultural crops.

Green June beetle larvae are important as nutrient recyclers of organic matter in soil. Both larvae and adults are large, energy rich food sources for insectivorous mammals and birds. Blue jays are especially fond of the adults and will preferentially feed on gravid females. In addition to vertebrate predators, a large wasp, Scolia dubia, is a significant natural enemy of green June beetle larvae and those of other large burrowing scarab beetles. Adult wasps sting and paralyze June bug larvae, then lay eggs on them. Wasp larvae feed on the incapacitated larva, eventually killing it.

Contact Us: For advice about pest identification or diagnosis, contact the LSU AgCenter Department of Entomology.

References

Alcock, J. 2016. The green June beetle (Cotinis nitida) (Coleoptera: Scarabaeidae): local variation in the beetle’s major avian predators and in the competition for mates. Journal of Natural History 50: 661-667.

Barnes, J.K. 2006. Green June Beetle. Dept. Entomology. Univ. Arkansas Div. of Agr. Coop. Ext. Service. Arkansas Arthropods No. 41. (accessed 2 February 2026).

Billeisen, T. 2023. Green June beetles in turfgrass. NC State Extension. (accessed 2 February 2026).

Brandenburg, R.L. and T. Billeisen. 2017 (revised). White grubs in turf. TurfFiles. NC State Extension. (accessed 2 February 2026).

Deloya A.C., Ratcliffe B.C. (1988) A synopsis of the genus Cotinis in Mexico with description of three new species (Coleoptera: Scarabaeidae: Cetoniinae). Acta Zoologica Mexicana 28: 1‒52.

P4049

4/27/26
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