Phyllophaga subtonsa
(LeConte, 1856)
May beetle, June beetle
Phyllophaga subtonsa is a of May beetle in the Scarabaeidae. Like other members of the , it is characterized by activity and larval development as white in soil, feeding on plant roots. The species is found in the eastern and central United States. Adults are attracted to lights and are most active during late spring and early summer. The genus Phyllophaga is one of the most species-rich in North America, with over 400 species, making species-level identification often difficult without examination of genitalia.
Pronunciation
How to pronounce Phyllophaga subtonsa: /ˌfaɪloʊˈfeɪɡə ˌsʌbˈtɒnsə/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
identification within Phyllophaga typically requires examination of male and female genitalia. P. subtonsa can be distinguished from similar species by subtle morphological characters, though specific diagnostic features for this species are not well documented in readily accessible literature. are generally brown to black, robust, and oval in shape, with (fan-like) . The pronotum and may show subtle surface sculpturing or setation patterns that aid in identification.
Distribution
Eastern and central United States. GBIF records indicate presence in Alabama, Georgia, Indiana, Maryland, Mississippi, New York, Tennessee, Virginia, and Wisconsin.
Seasonality
are active primarily in late spring through early summer (May-June), typical for the . Larvae are present in soil year-round, with development spanning multiple seasons.
Diet
Larvae feed on roots of grasses and other plants in soil. feed on foliage and flowers of various plants, though specific records for this are limited.
Life Cycle
Complete with , larva, pupa, and stages. Larvae are the familiar "white " that develop in soil over one to three years depending on and latitude. Adults emerge, mate, and females oviposit in soil. The specific developmental duration for P. subtonsa has not been documented.
Behavior
are and attracted to lights. Males use their to detect female . Both sexes may be found on vegetation at night, though they are primarily ground-dwelling or found on low vegetation.
Ecological Role
Larvae function as root-feeding /herbivores in soil , contributing to nutrient cycling and soil aeration. serve as and prey for various vertebrate and . The is part of the supporting in Tiphiidae, Thynnidae, and Pelecinidae.
Human Relevance
May beetles in the Phyllophaga are occasionally pests of agricultural crops and turfgrass when larval densities are high. Specific economic impact data for P. subtonsa is not documented, though the is presumably of minor importance compared to more abundant .
Similar Taxa
- Phyllophaga cribrosaBoth are flightless May beetles with similar body forms, but P. cribrosa is easily distinguished by its oval, convex shape, shining black coloration, cribrose (sieve-like) surface texture, and distinct longitudinal elytral furrows. P. cribrosa is restricted to Oklahoma and Texas, while P. subtonsa occurs further east.
- Polyphylla speciesPolyphylla (lined June beetles) are larger, chunkier beetles with strikingly enlarged, fan-like in males. They are primarily sand-dune in the western and southwestern U.S., whereas P. subtonsa is more broadly distributed in eastern deciduous forest and grassland .
More Details
Taxonomic complexity
The Phyllophaga contains over 400 in North America, making it one of the most species-rich genera in the fauna. Species boundaries are often subtle and require knowledge to discern. Many species remain poorly known biologically, with females of some species still undescribed or unknown.
Parasitoid associations
of Phyllophaga , including presumably P. subtonsa, are for several lineages. The American Pelecinid Wasp (Pelecinus polyturator) is a well-known parasitoid of Phyllophaga grubs, as are members of the wasp Myzinum and Myzine ( Thynnidae/Tiphiidae).