Xylosandrus morigerus (Blandford)

Dole, Stephanie A. & Beaver, Roger A., 2008, A Review of the Australian Species ofXylosandrusReitter (Coleoptera: Curculionidae: Scolytinae), The Coleopterists Bulletin 62 (4), pp. 481-492 : 481-492

Xylosandrus morigerus (Blandford)

Xyleborus morigerus Blandford, 1894 , Insect Life 6: 264.

Xylosandrus morigerus (Blandford) : Browne, 1963, Ent. Ber. 23: 55.

Xyleborus difficilis Eggers, 1923 , Zool. Meded. 7: 174. Synonymy Bright and Skidmore 1997: 4, 169.

Although Wood and Bright (1992) considered Xylosandrus difficilis to be a distinct species from X. morigerus , we have followed Bright and Skidmore (1997) and treat it as a synonym of the latter species. Morphologically the two differ in little more than size, with specimens referred to X. difficilis being larger. DNA sequence data is so far inconclusive (S. A. Dole and A. I. Cognato, in prep.) and a study of genetic variation across populations may be necessary to support or refute this synonymy. Other synonyms are given by Wood and Bright (1992). Dorsal and lateral photographs of the species (as X. difficilis ) are given by Zimmermann (1992). The species is of Oriental origin, but has been introduced through human agency into Africa, North and South America, and the Pacific islands, and now has an almost circum-tropical distribution (C.A.B.International 2005). All Australian specimens that we have seen (more than 70) were collected in tropical and subtropical areas of Queensland between 15 ° 30 9 S and 19 ° 16S, and 145 ° 12 9 E and 147 ° 03 9 E at altitudes from 10– 850 m.

X.morigerus was described from specimens intercepted in the United Kingdom in orchid ( Dendrobium sp. ) pseudobulbs originating from New Guinea, and the first Australian record ( Schedl 1942) was also from Dendrobium . However, it is more usually a twig and shoot borer, with a very wide variety of hosts ( Schedl 1963; C.A.B. I. 2005). Almost any broad-leaved tree or sapling can potentially be attacked, although the species has not yet been recorded from conifers. It can be important as a pest of crop and ornamental trees, and is well-known as a pest of coffee ( Browne 1968; Le Pelley 1968). It frequently infests shade trees in coffee plantations. Its attacks are sometimes primary on apparently healthy hosts. The biology, natural enemies and control of the species have been reviewed by Beaver (C.A.B. I. 2005). The species is potentially of economic importance in Queensland.