Xylosandrus crassiusculus (Motschulsky)

Beaver, R. A., Sittichaya, W. & Liu, L-Y., 2014, A Synopsis of the Scolytine Ambrosia Beetles of Thailand (Coleoptera: Curculionidae: Scolytinae), Zootaxa 3875 (1), pp. 1-82 : 69-70

154. Xylosandrus crassiusculus (Motschulsky)

Phloeotrogus crassiusculus Motschulsky, 1866: 403 .

Xylosandrus crassiusculus (Motschulsky) : Wood, 1977: 68.

Thai distribution: C: Chanthaburi, Kanchanaburi, Nakhon Nayok; N: Chiang Mai ( Beaver & Browne 1975 as Xyleborus semiopacus Eichhoff ), Lampang, Mae Hong Son, Nan, Phetchabun, Phitsanulok ; N-E: Chaiyaphum, Khon Kaen, Loei, Sakhon Nakhon; S: Chumphon, Nakhon Sri Thammarat, Surat Thani, Trang .

New records: More than 400 specimens have been examined from all regions of the country.

Other distribution: The species is native to and widespread through the Oriental region, extending North to Japan and Korea, and East to New Guinea, Fiji and Samoa; presumably originally imported to tropical Africa, but now widespread in the Afrotropical region; imported to and established in Italy and the southern U.S.A. (5)

Biology: Strongly polyphagous ( Dole & Cognato 2010). The basic biology has been described by Browne (1961a), Schedl (1963) (both as Xyleborus semiopacus ), and Beaver (1988) amongst others. Flight activity, and the attraction of flying adults to ethyl alcohol has been studied in the southern U. S. A. by Reding et al. (2011, 2013), attack densities and adult emergence on various hosts by Mayfield et al. (2013), and attraction to volatiles from the symbiotic ambrosia fungus by Hulcr et al. (2011). This is a species of economic importance because, like Xylosandrus compactus , it can attack and breed in healthy shoots and twigs. This can result in the introduction of pathogenic fungi ( Sreedharan et al. 1991, Davis & Dute 1997). It seems to be an infrequent pest in the Oriental and Afrotropical regions, although attacks on transplants have been recorded (e.g. Browne 1968). In Thailand it attacks newly sawn rubberwood ( Kangkamanee et al. 2011), and is common in durian plantations ( Sittichaya et al. 2012).

Illustrations: P (e.g. Atkinson 2013, Dole & Cognato 2010, Hulcr 2013, PaDIL 2014); D ( Maiti & Saha 2004).