Anomala viridana

Potential Invader

Common name(s)

green chafer

Taxonomy

Family: Scarabaeidae Subfamily: Rutelinae Genus: Anomala Species: Anomala viridana (Kolbe, 1886)

Adult diagnosis

Total body length 18.0–24.0 mm (0.71–0.94 in). Body shape ovate. Color brownish-green with metallic sheen. Front tibia with two external teeth; apical tooth long, longer in female than male; basal tooth feeble in male, more evident in female. Front inner claw bifurcate; bifurcate claw strongly sinuate in male, simple in female. Hind tibia with inner margin simple, not greatly dilated at the middle.

Larval diagnosis

Undescribed. For Anomala (Ritcher, 1966): Grub C-shaped, not hump-backed, cylindrical, whitish. Lacinia of maxilla with 2 apical unci equal in size. Maxillary stridulatory area with 4–7 sharp, recurved teeth. Epipharynx with 2–4 prominent heli. Final antennal segment with single dorsal sensory spot. Spiracles on abdominal segments 7 and 8 similar in size and conspicuously larger than spiracles on abdominal segments 1–6. Anal slit transverse, arcuate; bordered by several irregular rows of stout setae. Lower anal lip bearing patch of 13 hamate setae.

Native range

Northeast Asia. This species has been recorded from Japan (Kobayashi and Matsumoto, 2011), Korea (Park et al, 2014), and Sakhalin and the Kurile Islands in the Russian Far East (Bezborodov, 2014)

Plant host(s)

In the Kurile Islands, adults of this chafer have been recorded on the herb sea-watch or seacoast angelica (Angelica lucida) (Krivolutskaya, 1973) as well as northern water hemlock (Cicuta virosa), hemlock-parsley (Conioselinum chinense), and giant knotweed (Fallopia sachalinensis) (Bezborodov et al., 2011).

Life history

Poorly known. Presumably, the life history of this species is similar to that of the closely related oriental beetle (Anomala orientalis). Larvae develop in soil where they feed upon the roots of a number of plant species. Adults are likely nocturnal, generalist folivores.

Pest potential

Low. This species has been recorded on Wake Island in abundance (Hawaiian Entomological Society, 1953) and potentially could spread to Hawaii or Guam. It is not apparent that Anomala viridana causes significant damage to plants of horticultural or agricultural importance, but native plants could possibly be impacted.

Status in Hawaii

Recorded, not established. This species was recorded in 1952 as a hitchhiker on aircraft coming to Honolulu airport from Wake Island where it is, or was, established and abundant (Hawaiian Entomological Society, 1953).

Status in Guam

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

Potential distribution and dispersal pathway

Although this species is temperate in origin, its establishment on Wake Island demonstrates its ability to survive in tropical climates. As such, it should be regarded as having the potential to spread to both Hawaii and Guam. Further, the possibility of the introduction of the Anomala viridana to the mainland U.S. must also be considered. As previously mentioned, this species is a known hitchhiker on aircraft, and it is reasonable to expect that marine cargo also represents a potential vehicle of introduction.

Similar species

Anomala viridana is one of five Anomala species recorded from Hawaii and Guam, along with Anomala orientalis, Anomala sulcatula, Anomala cuprea, and Anomala albopilosa. It can be separated from the other species by examination of the bifurcate male front claw (strongly sinuate in A. viridana versus weakly sinuate in A. albopilosa and curved but non-sinuate in A. orientalis and A. sulcatula), male hind tibia (A. cuprea with hind tibia not greatly dilated at the middle on the inner margin versus hind tibia dilated at the middle in A. sulcatula), and total body length (A. cuprea 17.0–26.0 mm [0.67–1.02 in] versus less than 13.0 mm [0.51 in] in A. orientalis).

Other names (synonyms)

Anomala borealis Arrow, Anomala izuensis Sawada, Anomala japonica Arrow, Euchlora mongolica Lewis, and Euchlora viridana Kolbe

Report your observation

In Hawaii, this species represents a new invasive species. Prevent the spread of this species by reporting your observation at our iNaturalist project.

Anomala viridana male; photo by E.L. Engasser

Anomala viridana male; photo by E.L. Engasser

Anomala viridana male; photo by E.L. Engasser

Anomala viridana male; photo by E.L. Engasser

Anomala viridana male foretibia; photo by E.L. Engasser

Anomala viridana male foretibia; photo by E.L. Engasser

Anomala viridana male foreclaw; photo by E.L. Engasser

Anomala viridana male foreclaw; photo by E.L. Engasser

Anomala viridana female; photo by E.L. Engasser

Anomala viridana female; photo by E.L. Engasser

Anomala viridana male genitalia, dorsal view; photo by E.L. Engasser

Anomala viridana male genitalia, dorsal view; photo by E.L. Engasser

Anomala viridana male genitalia, lateral view; photo by E.L. Engasser

Anomala viridana male genitalia, lateral view; photo by E.L. Engasser

distribution map for Anomala viridana

distribution map for Anomala viridana