Lepidiota carolinensis

Native

Common name(s)

none known

Taxonomy

Family: Scarabaeidae Subfamily: Melolonthinae Genus: Lepidiota Species: Lepidiota carolinensis Arrow, 1939

Adult diagnosis

Total body length 19.0–21.9 mm (0.74–0.86 in). Body shape oblong, cylindrical, tapering slightly posteriorly. Color yellowish-brown; head, pronotum, and scutellum brownish-red. Antennae 10-segmented; club 3-segmented; club subequal in length to scape (male) or half the length of scape (female). Elytra with numerous small white scales; weakly striated.

Larval diagnosis

Undescribed. For Lepidiota (Ahrens et al., 2007): Grub C-shaped, not hump-backed, cylindrical, whitish. Galea and lacinia fused proximally but separated distally or tightly fitted together. Frons rugose. Claws of hind legs reduced. Raster with 2 parallel rows of setae. Anal opening Y-shaped.

Native range

Western Micronesia. This species is endemic to the Marianas (including Guam) and Palau (Cartwright and Gordon, 1971).

Plant host(s)

Not recorded. In many related Lepidiota species, adults are generalist folivores and larvae feed upon grass roots (Kuniata and Young, 1992).

Life history

Poorly known. Cartwright and Gordon (1971) noted that this species comes to lights, suggesting nocturnal habits. It is likely that adults are folivores and that the larvae develop within soil where they feed on grass roots. Such habits are seen in related Lepidiota species (Kuniata and Young, 1992). There are likely one or two generations per year.

Pest potential

Probably none. There are no records of this poorly known species feeding on commercially important plants. However, a considerable number of related species are significant larval pests of grasses including (but not limited to) Lepidiota frenchi, L. squamulata, and L. stigma (all of which all feed on sugarcane) (Britton, 1962; Kuniata and Young, 1992), L. reuleauxi (a pest of sugarcane and corn) (Kuniata and Young, 1992), and L. vogeli (a pest of pasture grasses) (Barrett, 1966).

Status in Hawaii

Not established or recorded. There are no records of this species from Hawaii.

Status in Guam

Native. Cartwright and Gordon (1971) reported this species as endemic to Micronesia, occurring in the Marianas and Palau.

Potential distribution and dispersal pathway

It appears unlikely that this rare, native species would spread beyond its small, natural range. However, because this scarab is attracted to lights at night (Cartwright and Gordon, 1971), it is possible this species could be attracted to well-lit ports and airports where it could be transported to new regions.

Similar species

This scarab is somewhat similar to Holotrichia bipunctata, a common species on Guam. The species are separated by size (19.0–21.9 mm [0.74–0.86 in] in Lepidiota carolinensis versus 13.8–18.1 mm [0.54–0.71 in] in H. bipunctata) and elytra (L. carolinensis elytral surface with numerous, small, white scales versus scales lacking in H. bipunctata).

Other names (synonyms)

none known

Report your observation

Report your observation of this rare and native Guamanian species at our iNaturalist project.

Lepidiota carolinensis male dorsal view; photo by J Buck Dunlap

Lepidiota carolinensis male dorsal view; photo by J Buck Dunlap

Lepidiota carolinensis male lateral view; photo by J Buck Dunlap

Lepidiota carolinensis male lateral view; photo by J Buck Dunlap

Lepidiota carolinensis male head, dorsal view; photo by J Buck Dunlap

Lepidiota carolinensis male head, dorsal view; photo by J Buck Dunlap

Lepidiota carolinensis male genitalia, caudal view; photo by J Buck Dunlap

Lepidiota carolinensis male genitalia, caudal view; photo by J Buck Dunlap

Lepidiota carolinensis malegenitalia, lateral view; photo by J Buck Dunlap

Lepidiota carolinensis malegenitalia, lateral view; photo by J Buck Dunlap

distribution map for Lepidiota carolinensis

distribution map for Lepidiota carolinensis