Polyphylla barbata

Cazier, 1938

Mount Hermon June Beetle

Polyphylla barbata is a federally endangered scarab beetle to a single restricted locality in the Zayante sandhills of Santa Cruz County, California. The occupies less than 1,500 acres of , making it one of the most geographically limited beetles in North America. are active in mid-summer, with males flying at dusk to locate flightless females using -detecting . The species severe habitat loss from sand mining and development, with over 40% of its sandhills habitat already destroyed.

Polyphylla barbata at Mt Diablo by Laloer. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Polyphylla barbata: //ˌpɒlɪˈfɪlə bɑːrˈbɑːtə//

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

Identification

Approximately 2 cm in length; black and brown coloration with broken white longitudinal stripes on the surface; covered with a thin coat of hairs; females slightly larger than males; males possess the enlarged, fan-like characteristic of the Polyphylla, which they hold splayed to detect female . Distinguished from other Polyphylla by its restricted range and association with the Zayante sandhills; most similar to other western sand-dune inhabiting Polyphylla but separated by geography and subtle morphological features.

Images

Habitat

Ponderosa pine forest and chaparral with open, sandy pockets in volcanic hills; specifically restricted to the Zayante sandhills characterized by deep, well-drained sandy soils derived from marine deposits.

Distribution

to California, United States; known only from Santa Cruz County in the Santa Cruz Mountains; single occurrence spanning under 1,500 acres (6.1 km²) centered on Mount Hermon, Scotts Valley, and Ben Lomond.

Seasonality

males fly between mid-June and late July, with peak activity between 8:45 and 9:30 pm; females remain underground except to mate.

Diet

may not feed at all; larvae feed underground on plant roots and mycorrhizal fungi.

Life Cycle

Underground-dwelling larva for most of ; life cycle duration estimated at 2–3 years; male adulthood lasts approximately one week; female dies shortly after laying .

Behavior

Males fly actively at dusk with wings producing a crackling sound; males use greatly enlarged, splayed to detect female ; females are flightless and spend nearly all their time underground, emerging only to mate; males attracted to lights after dusk but cease activity shortly to several hours after sunset.

Ecological Role

Larval root-feeding may influence plant structure in the sandhills ; serves as a component of the unique and threatened Zayante sandhills fauna.

Human Relevance

Federally listed in the United States; threatened by sand mining, urban development, and fire suppression altering native plant ; conservation attention has focused on the Zayante sandhills , which also supports other rare and endangered species including the Zayante band-winged grasshopper (Trimerotropis infantilis) and several rare plants.

Similar Taxa

Polyphylla hammondiSimilar large size, sand dune preference, and male of splayed for detection; distinguished by geographic separation (Great Plains and western interior) and morphological details.
Polyphylla decemlineataShared characteristics including enlarged male and activity; distinguished by ten distinct longitudinal white stripes and much broader distribution across western North America.
Trimerotropis infantilisCo-occurs in the Zayante sandhills and shares endangered status; not a but another sandhills with overlapping conservation concerns.