Family: Scarabaeidae Subfamily: Rutelinae Genus: Anomala Species: Anomala viridana (Kolbe, 1886)
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.
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.
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).
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.
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.
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).
Not established or recorded. There are no records of this species from Guam.
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.
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).
Anomala borealis Arrow, Anomala izuensis Sawada, Anomala japonica Arrow, Euchlora mongolica Lewis, and Euchlora viridana Kolbe