Adoretus compressus

Pest

Common name(s)

rose beetle, compressed rose beetle

Taxonomy

Family: Scarabaeidae Subfamily: Rutelinae Genus: Adoretus Species: Adoretus compressus (Weber, 1801)

Adult diagnosis

Total body length 10.0–12.0 mm (0.39–0.47 in). Body elongate oval. Color brownish with numerous distinctive, cream-white setae; setae sometimes missing in worn specimens. Front tibia with 3 teeth at lateral margin; teeth may be worn in older specimens. Last sternite of female with apex rounded posteriorly; weakly quadrate in male.

Larval diagnosis

Undescribed. For Adoretini (Ritcher, 1966): Grub C-shaped, not hump-backed, cylindrical, whitish. Maxilla with galea and lacinia entirely fused. Lacinia of maxilla with 3 unci. Mandible with a ventral, oval, stridulatory area consisting of transverse, granular ridges. Maxillary stridulatory area with 8 or more, sharp, recurved teeth. Plegmatia present. Haptomerum of epipharynx with a dense, transverse, comb-like row of 6–9 heli. Last antennal segment with a single, dorsal sensory spot. Raster with a subtriangular teges of hamate setae; palidia absent.

Native range

Asia, Africa. This beetle is widespread in the Old World tropics, with records from South Africa, India, Sri Lanka, Malaysia, Mauritius, Thailand, Indonesia, and Papua New Guinea (McQuate and Jameson, 2011).

Plant host(s)

This species has been recorded feeding on a range of economically important plants including lychee (Litchi chinensis) (McQuate and Jameson, 2011), rambutan (Nephelium lappaceum) (Muniappan, 2012), rice (Oryza spp.) (International Rice Research Institute, 1986), corn (Zea mays) (CIMMYT, 1989), oil palm (Elaeis guineensis), banana (Musa spp.), rose (Rosa spp.), grape (Vitis spp.), okra (Abelmoschus esculentus), cotton (Gossypium spp.), sweet potato (Ipomoea batatas), coffee (Coffea spp.), cocoa (Theobroma cacao), and tea (Camellia sinensis) (Muniappan, 2012).

Life history

Poorly known: This species is a generalist folivore with the nocturnal adults feeding on a broad range of host plants (Pena et al., 2002). Similar to Adoretus sinicus, host plants often show characteristic lace-like leaf damage to the leaves (Muniappan, 2012). Eggs are laid in soil, often around plant roots. A report of five larval instars is likely erroneous (Pena et al., 2002).

Pest potential

Significant. This species is a clear biosecurity hazard. It is known to feed on a wide range of economically important plant species and is closely related to species with clear histories of invasive establishment (McQuate and Jameson, 2011). Damage from adult feeding can be significant enough to substantially lower fruit crop yields (Pena et al., 2002).

Status in Hawaii

Established. Nishida (2002) recorded this species from Oahu. Because of the great difficulty in separating this species from the common and extremely similar Adoretus sinicus, its abundance on the island is unclear.

Status in Guam

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

Potential distribution and dispersal pathway

This species is attracted to lights at night, and it is likely that it would be attracted to well-lit ports and airports. This would allow for hitchhiking on marine or air cargo. Further, it is possible that adults or larvae could be transported in the movement of nursery plants.

Similar species

This species is extremely similar to the closely related Adoretus sinicus. The two species cannot reliably be separated based on external morphology. Identification requires dissection and examination of the male genitalia.

Other names (synonyms)

Adoretus umbrosus Burmeister

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Adoretus compressus; photo by E.L. Engasser

Adoretus compressus; photo by E.L. Engasser

Adoretus compressus; photo by E.L. Engasser

Adoretus compressus; photo by E.L. Engasser

Adoretus compressus male genitalia, caudal view; photo by E.L. Engasser

Adoretus compressus male genitalia, caudal view; photo by E.L. Engasser

Adoretus compressus male genitalia, lateral view; photo by E.L. Engasser

Adoretus compressus male genitalia, lateral view; photo by E.L. Engasser

Adoretus sinicus characteristic leaf damage upon wax apple; photo by M.L. Jameson

Adoretus sinicus characteristic leaf damage upon wax apple; photo by M.L. Jameson

distribution map for Adoretus compressus

distribution map for Adoretus compressus