Cotinis nitida

(Linnaeus, 1764)

green June beetle, June bug, June beetle, Common Green June Beetle

Cotinis nitida is a native North American scarab beetle in the flower chafer Cetoniinae. are large, metallic green beetles active during daylight hours, often seen flying loudly in search of ripe or fermenting fruit. The completes a one-year , with larvae feeding underground on decaying organic matter and occasionally damaging turfgrass roots through tunneling . Though sometimes mistaken for the Japanese beetle, this species is significantly larger and behaviorally distinct, and is generally considered a minor agricultural pest.

Cotinis nitida by (c) Thomas Koffel, some rights reserved (CC BY), uploaded by Thomas Koffel. Used under a CC-BY license.

Cotinis nitida larva by Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org. Used under a CC BY 3.0 license.

Green june beetle2 by Coveredinsevindust at English Wikipedia. Used under a CC BY-SA 3.0 license.

Pronunciation

How to pronounce Cotinis nitida: /koʊˈtiːnɪs ˈnɪtɪdə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

are readily identified by their large size (15–22 mm), metallic green coloration with gold sides, and loud, buzzing during daytime hours. The combination of stout body, relatively short legs, and bright shiny green underside separates them from smaller, duller brown scarabs. Males can be confirmed by the small horn on the . Larvae are distinctive among white : they are unusually large (up to 40 mm), crawl on their backs using stiff abdominal bristles, and move with exceptional speed underground. The transparent terminal abdominal segment revealing gut contents is visible in all scarab larvae but the rapid, back-crawling locomotion is diagnostic for this .

Images

Habitat

occur in diverse open including lawns, fields, pastures, forests, and gardens. They are particularly associated with areas containing ripe or decaying fruit, fermenting tree sap, and compost or manure heaps where females oviposit. Larvae inhabit sandy to loamy soils rich in organic matter, especially pastures amended with broiler litter, manure, or other decaying plant material. Preference shown for older fields with high organic matter content over newly developed areas.

Distribution

Eastern United States and southeastern Canada, with highest abundance in the South. Range extends from New Brunswick south to Georgia, and westward to Nebraska, Oklahoma, Texas, and possibly California. Distribution overlaps with related figeater beetle (Cotinis mutabilis) in Texas. Recorded from Connecticut, Florida, Indiana, Iowa, Kansas, Maryland, Missouri, Nebraska, New York, North Carolina, Oklahoma, South Carolina, Texas, and Virginia.

Seasonality

emerge from pupal and appear above ground in June, with activity continuing through September. Peak abundance corresponds with summer months when occurs. Third instar larvae collected December through February; occurs after third larval stage. Complete one-year .

Diet

feed on sugar-rich foods, particularly ripe and decaying fruits including berries, grapes, peaches, nectarines, apples, pears, and figs. Strongly attracted to rotting fruit and fermenting odors from tree wounds. Also feed on flower nectar and pollen. Larvae feed primarily on humus, mold, and decaying organic matter in soil; occasionally chew tender grass roots but obtain most nutrition from decomposition of plant material.

Host Associations

Trichosporon cutaneum - gut yeast floraMost abundant yeast in guts; produces volatile serving as
Spiroplasma clarkii - gut bacteriumCultured from guts of both and larvae

Life Cycle

Complete (holometabolous) with one-year cycle. Mating occurs in early morning; female secretes strongly scented milky fluid attracting males. Female lays 60–75 underground over two-week period. Eggs white and elliptical, becoming spherical as larvae develop; hatch in approximately 18 days. Larvae () grow to 40 mm, white with brownish-black and brown ; twice before winter, with third instar lasting nearly nine months. occurs in oval cocoon constructed of soil particles bound by larval fluid; pupa white initially, developing greenish tints before . emerge after 18-day pupal period.

Behavior

are and fly actively during daylight with loud, buzzing often audible before beetles are seen. Attracted to fermenting odors including alcohol in decaying sap and fruit; feeding at sap flows can produce lethargic, uncoordinated . Females dive headlong into compost and manure to oviposit. Larvae exhibit unique back-crawling locomotion using stiff abdominal bristles; travel speed considered fastest of any U.S. scarab . Intense male-male competition for mates occurs, with multiple males attempting simultaneous copulation with single females.

Ecological Role

Saprophagous decomposer contributing to breakdown of decaying plant material in soil. function as minor when feeding on flowers. Serve as prey for diverse vertebrate and . Larval tunneling aerates soil but can damage plant root systems and turfgrass in high densities.

Human Relevance

Minor agricultural pest: damage ripe stone fruits and grapes, particularly following initial injury by other insects; larvae occasionally damage turfgrass and ornamental plant roots, especially in mulched areas. Larvae considered more injurious than adults. Frequently mistaken for destructive Japanese beetle, leading to unnecessary concern. Attracted to ethanol/red wine-baited traps used for collecting. Used in educational settings to demonstrate scarab beetle diversity and larval .

Similar Taxa

Cotinis mutabilisSouthwestern figeater beetle; similar size, coloration, and but geographically separated with only possible range overlap in Texas; less destructive to crops
Popillia japonicaJapanese beetle; much smaller (8.9–11.8 mm), with distinctive white abdominal hair tufts and striated ; pest with skeletonizing leaf damage pattern
Phyllophaga spp.Brown May/June beetles; dull brown coloration, larger body index, longer legs, activity, and different larval
Euphoria fulgidaEmerald flower scarab; similar metallic green color but more active , smaller size variation, and different geographic distribution

Misconceptions

Commonly but incorrectly called "June ," a name properly applied to Phyllophaga . Frequently misidentified as Japanese beetle due to metallic green coloration, despite substantial size and behavioral differences. The name "" itself causes confusion with brown "June beetles" (Phyllophaga). are sometimes assumed to be major agricultural pests; while they damage ripe fruit, they typically follow other insects rather than initiating injury, and larval damage is generally localized to high-organic-matter soils.