Anthonomus (Anthonomus)

Clark, Wayne E. & Burke, Horace R., 2010, The Anthonomus juniperinus group, with descriptions of two new species (Coleoptera: Curculionidae), Insecta Mundi 2010 (119), pp. 1-10 : 2

Anthonomus (Anthonomus) juniperinus group

Description. Body elongate-oval to more strongly ovate, length 1.5 to 3.0 mm. Vestiture consisting of slender, sometimes setalike, scales dorsally and ventrally sparsely to more densely distributed; not obscuring integument except occasionally on pronotum; elytral scales may be evenly distributed or partially denuded posteromedially forming a V-shaped pattern. Integument testaceous to reddish in color. Antennal funicle (including pedicel) with 7 articles. Rostrum slightly curved, nearly straight in some cases; joins head at slight angle. Eyes slightly to moderately strongly convex when viewed from above; may be somewhat protuberant posteriorly. Procoxae large, contiguous. Mesocoxae separated by about 1/3 width of coxa. Femora slender to moderately stout; femoral teeth minute to small, acutely or bluntly pointed, sometimes obsolete. Tibiae straight; metatibia with minute to small apical mucro. Tarsal claws each with distinct, small to minute or obsolete basal tooth. Abdominal sternum 1 along midline about length of sterna 2 + 3, sterna 3 and 4 subequal in length, 4 slightly longer. Median lobe with sides subparallel, apex rounded, membranous dorsally. Hosts. Juniperus spp.

Diagnosis. The Anthonomus juniperinus group is relatively easily distinguished from other groups of the genus by a combination of characters: small size ( A. rileyi is among the smallest species of the genus); testaceous to reddish integument with vestiture of elongate, sometimes setalike scales; rostrum feebly curved and meeting head at a slight angle; minute to small tooth on femora, sometimes obsolete; and obsolete to short tooth on the tarsal claws. While the minute (and sometimes absent) to small teeth on the femora and tarsal claws are not characters unique to the juniperinus Group, this is unusual for species in the nominate subgenus. This combined with the elongate, often setalike scales and the rostrum meeting the head at a slight angle distinguishes the group. Although a rather subtle character, the angulate attachment of the rostrum to the head is perhaps the most distinctive single character defining the group.

Relationship to other species groups of Anthonomus . It is not clearly evident where the juniperinus group fits in Anthonomus other than that it is obviously a member of the nominate subgenus. Dietz (1891) recognized the juniperinus group within the subgenus Anthonomus to include A. juniperinus , Anthonomus dissimilis Dietz and Anthonomus orchestoides Dietz. On the basis of a recent study of the genus, neither of the latter two species is considered to be closely related to A. juniperinus . The characters Dietz used to distinguish the group were the small basal tooth of the tarsal claws, subequal abdominal sterna, and “pubescence” on both dorsal and ventral surfaces of the body. Blatchley (in Blatchley and Leng 1916) used the same grouping (his Group F) based essentially on the same characters cited by Dietz. In an attempt to broaden the character base used in the taxonomy of the Anthonomini, Burke (1968) made a comparison of pupal characters in a wide array of species of the tribe, including A. juniperinus . Based upon pupal characters, A. juniperinus keys out with Anthonomus nigrinus Boheman , another species with which, on the totality of its characters, it seems to have no close relationship. Results obtained by Ahmad and Burke (1972) in comparison of larval characters of A. juniperinus with those of 43 other species of Anthonomini were similarly inconclusive as to placement of the species in the genus. Addition of two previously undescribed species to the juniperinus group does not contribute to further understanding of where these taxa should be placed in the genus. At present, it can only be concluded that the three species constitute a recognizable group that should be assigned to the nominate subgenus of Anthonomus .