Phyllophaga anxia

Distinguished from other Phyllophaga species by combination of large size (17.2–22.5 mm), dark brown to black coloration, and ten antennomeres. Specific identification within genus Phyllophaga often requires examination of male and female genitalia due to high species diversity (400+ North American species). Flight initiation 12–45 minutes after sunset when soil temperature ≥10°C. Males distinguished by light attraction behavior during pre-copulatory flight lasting over 1 hour until peak coupling near 2230 h.

Agricultural fields, pastures, and forests. Adults feed on foliage of host trees including elm, willow, poplar, apple, cherry, box-elder, hackberry, linden, mountain ash, and oak. Larvae develop in soil, feeding on roots. In Quebec, pastures and infested agricultural fields represent primary study habitats.

North America: widespread across United States (particularly eastern half but throughout country) and southern Canada. Documented in Canadian provinces: Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland, Northwest Territories, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan. US states: California, Colorado, Georgia, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Mississippi, Montana, Nevada, New Jersey, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Wisconsin. Also recorded from Guadeloupe (Neotropical).

Adult flight season primarily May through June in Quebec. First flight of overwintered adults occurs mid-May with accumulation of approximately 156 degree-days above 5°C beginning 1 April. Flight activity nocturnal: initiates 12–45 minutes after sunset, concludes with morning return flight to soil triggered by light intensity increasing to about 1.0 lux. Duration of flight 10–46 minutes early in season, 20–35 minutes in early June. Peak oviposition occurs in early June.

Adults feed on foliage of trees and shrubs: elm, willow, poplar, apple, cherry, box-elder, hackberry, linden, mountain ash, and oak. Larvae feed on roots in soil.

Complete metamorphosis. Overwintered adults emerge mid-May. Eggs laid in soil; larvae (white grubs) feed on roots through three instars. Third-instar larvae most susceptible to mite infestation. Prepupae and pupae formed in soil. New adults emerge following year. Copulation lasts 3 hours or more; maximum coupling near 2230 h.

Nocturnal flight activity cued by low light intensity (1.0–96.9 lux) and soil temperature ≥10°C. Males exhibit pre-copulatory flight to light lasting over 1 hour. Morning return flight to soil triggered by dawn light levels. Early June flight directed into trees or to oviposition sites within fields. Attracted to n-hexanoic acid (demonstrated in field assays), with potential for use in management strategies.

Agricultural pest causing damage to crops through larval root-feeding and adult defoliation. Serves as host for parasitoid wasps including Pelecinus polyturator (Pelecinidae) and Myzinum species (Thynnidae), as well as tachinid flies. Associated with 15 mite species across 5 families; Macrochelidae, Parasitidae, and possibly Eviphididae may partially regulate local populations. Prey for predatory beetles (Carabidae, Staphylinidae).

Major agricultural pest in Quebec, described as most common and destructive June beetle species in province. Larvae (white grubs) damage crops by root-feeding; adults defoliate host trees. Management strategies investigated using behavior-modifying chemicals: n-hexanoic acid identified as promising attractant, capturing approximately twice as many beetles as standard blacklight traps. Potential for use in aggregating beetles for destruction or deterring adults from crops.

• Phyllophaga fuscaNorthern June beetle with overlapping range in Quebec; similar nocturnal flight patterns and habitat preferences but distinct species with different flight timing and degree-day requirements.
• Phyllophaga cribrosaFlightless, diurnal species with oval convex shape and cribrose (sieve-like) elytral surface; easily distinguished from flying, nocturnal P. anxia by morphology and behavior.
• Polyphylla hammondiLarger, sand-dune inhabiting relative with fan-like antennae in males; distinguished by habitat specificity and greatly enlarged male antennae used for pheromone detection.

• scarab beetle
• June beetle
• May beetle
• white grub
• agricultural pest
• nocturnal
• root feeder
• defoliator
• North America
• parasitoid host

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Bug Eric: The American Pelecinid Wasp
• Bug Eric: Wasp Wednesday: Myzinum
• May | 2016 | Beetles In The Bush
• Acrididae | Beetles In The Bush | Page 4
• economic pests | Beetles In The Bush
• Insect parasites and predators of Phyllophaga anxia (LeConte) (Col., Scarabaeidae) in Quebec, Canada
• ACARI ASSOCIATED WITHPHYLLOPHAGA ANXIA(LECONTE) (COLEOPTERA: SCARABAEIDAE) IN SOUTHERN QUEBEC AND EASTERN ONTARIO
• A NOTE ON PELECINUS POLYTURATOR (HYMENOPTERA: PELECINIDAE), A PARASITE OF PHYLLOPHAGA ANXIA (COLEOPTERA: SCARABAEIDAE)
• Two eugregarina, Gregarina sp. and Actinocephalus sp., associated with the scarab Phyllophaga anxia, as observed in histological sections
• Field assays to determine attractancy of natural and synthetic lures to Phyllophaga anxia (LeConte) (Col., Scarabaeidae)1
• EFFECTS OF TEMPERATURE AND LIGHT INTENSITY ON NOCTURNAL ACTIVITY PATTERNS OF THE NORTHERN JUNE BEETLE, PHYLLOPHAGA FUSCA, AND THE COMMON JUNE BEETLE, P. ANXIA (COLEOPTERA: SCARABAEIDAE)