Anisandrus maiche Stark

Rabaglia, Robert J., Vandenberg, Natalia J. & Acciavatti, Robert E., 2009, First records of Anisandrus maiche Stark (Coleoptera: Curculionidae: Scolytinae) from North America, Zootaxa 2137, pp. 23-28 : 24

Anisandrus maiche Stark

( Figs. 1, 2, 4–6 )

Anisandrus maiche Stark 1936: 142 .

Anisandrus maiche Eggers 1942: 36 (Synonymy: Pfeffer 1944)

Diagnosis. Specimens of A. maiche can be distinguished from other members of Anisandrus occurring in North America by the smaller body size (<2.5 mm), by the impressed 2nd declivital interstriae and striae, and the raised 3rd declivital interstriae with numerous distinct granules ( Fig. 4 ). It is most similar to A. dispar , also a non-native species in North America, but is easily distinguished by its smaller body size (<2.5 mm vs.> 3.2 mm for A. dispar ), and the interstriae on the elytral disc which have only one row of seriate punctures ( Fig. 2 ) compared with 2–3 rows of punctures in A. dispar ( Fig. 3 ).

Distinguishing Anisandrus from other North American Xyleborina. Hulcr et al. (2007) restored the genus Anisandrus , and included species formerly in Xyleborus , Ambrosiodmus Hopkins and Cyclorhipidion Hagedorn. They state that Anisandrus belongs to a group of genera that are defined by a short, stout body, characteristically flattened antennal club, and, most importantly, the presence of a pronotal mycangial tuft of hairs ( Fig. 1 ). Anisandrus is very similar to Xylosandrus except that the procoxae of Anisandrus are contiguous ( Fig. 8 ), whereas those of Xylosandrus are separated ( Fig. 7 ). In the key to species of Xyleborus north of Mexico by Rabaglia et al. (2006), species that are now recognized as species of Anisandrus are characterized by having the antennal club distinctly and obliquely truncate with segment 1 corneous (couplet 1), the anterior margin of the pronotum distinctly armed by several coarse serrations, and the body <2.2 x as long as wide (couplet 2) ( Figs. 5, 6 ). The key is modified as follows to include A. maiche with alterations in bold type. An illustrated, online key (http://xyleborini.tamu.edu/keys.php) to North American Xyleborina will be updated to include Anisandrus in the generic key and the following key to the four species in North America.

Figures

FIGURES 1 – 8. Morphological illustrations of ambrosia beetles (subtribe Xyleborina): 1, Anisandrus maiche Stark, juncture of pronotum and elytron (dorsal view) showing pronotal mycangial tuft. 2, 3, detail of right elytral disk showing strial and interstrial punctures: 2, A. maiche; 3, A. dispar (Fabricius). 4, elytral declivity of A. maiche. 5, 6, habitus views of A. maiche: 5, dorsal view; 6 left lateral view. 7, 8, ventral view showing procoxae: 7, coxae well separated as in Xylosandrus spp.; 8, coxae contiguous, as in Anisandrus spp.