Silvanus difficilis is a species of silvan flat bark beetle widespread in Oriental region. It is introduced to Australia via timber and also to Costa Rica.[1][2]
| Silvanus difficilis | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Family: | Silvanidae |
| Genus: | Silvanus |
| Species: | S. difficilis
|
| Binomial name | |
| Silvanus difficilis Halstead, 1973
| |
Distribution
editMany Oriental countries including, Malaya, India,[3] Sri Lanka, Vietnam, Taiwan, Singapore, Sumatra, Java, Christmas Island, Sarawak, Borneo, Philippines, Moluccas, and New Guinea. Also found in Oceanian regions of Solomon Islands, Samoan Islands, and introduced to Australia.[4] There are records from West Africa, Britain,[5] New Ireland and Costa Rica.[6]
Description
editExtremely variable species in appearance, very similar to Silvanus lewisi, Silvanus robustus and Silvanus productus. Two distinct forms are described and identified: 'Normal form' and 'New Guinea form'. The 'Normal form' clearly identified from the 'New Guinea form' due to its short temple, and wider and shorter prothorax.[6]
Average length is about 2.17 to 2.64 mm. Body elongated, and slightly depressed. Body color ranges from dull brown to yellow-brown and covered with short, semi-erect, golden pubescence. Head broader than long. Punctures on frontal triangle often ocellate. Eyes are large with temples as long as eye-facets. Antennae broad and clubbed. Pronotum broad and more elongate. Pronotum puncturation is coarse and dense, similar to head. Prosternum with tuberculate surface which become rugose towards sides.[1] Prothorax convex, and elongated. Scutellum large, transverse and pubescent.[6]
Ecology
editAdults have been collected from Shorea robusta in India. They have found among commodities imported to Britain from the Oriental region.[1]
References
edit- ^ a b c "A revision of the genus Silvanus Latreille (sl)(Coleoptera: Silvanidae)" (PDF). hbs.bishopmuseum.org. Retrieved 2021-07-08.
- ^ Peck, Stewart B.; Heraty, John; Landry, Bernard; Sinclair, Bradley J. (1998). "Introduced Insect Fauna of an Oceanic Archipelago: The Galápagos Islands, Ecuador". American Entomologist. pp. 218–237. doi:10.1093/ae/44.4.218. Retrieved 2021-07-09.
- ^ Pal, T.K.; Gupta, T. Sen (April 1977). "A revision ofSilvanus(Coleoptera: Silvanidae) from India". Oriental Insects. pp. 269–284. doi:10.1080/00305316.1977.10434545. Retrieved 2021-07-09.
- ^ "Silvanus difficilis Halstead, 1973". Atlas of Living Australia. Retrieved 2021-07-08.
- ^ "SILVANUS MUTICUS SHARP, 1899: AN AMERICAN SILVANID FOUND OUT-OF-DOORS IN TWO GREEK ISLANDS" (PDF). Boll. Mus. Civ. St. nat. Venezia, 53 (2002) 2002: 207-211. Retrieved 2021-07-08.
- ^ a b c "Systematics of Silvanidae (Coleoptera: Clavicornia) from India and some neighbouring areas" (PDF). ir.nbu.ac.in. Retrieved 2021-07-08.