Paragrilus Saunders, 1871

Hespenheide, Henry A., 2002, A review of North and Central American Paragrilus Saunders, 1871 (Coleoptera: Buprestidae: Agrilinae), Zootaxa 43, pp. 1-28 : 2-4

Paragrilus Saunders, 1871

Paragrilus Saunders, 1871: 127 (replacement name for Clinocera Deyrolle ). Type species: Agrilus modicus Solier, 1833 (subsequent designation: Nelson 1987: 71). Clinocera Deyrolle 1864 , 116. (name preoccupied, Meigen 1803, Diptera ). Type species: unavailable (no type species designation)

Rhaeboscelis auct. not Chevrolat, 1837.

The genus has been most recently treated by Cobos (1976) in relation to the other genera in the subtribe Rhaeboscelidina , Rhaeboscelis Chevrolat and Ve lu t ia Kerremans. Examination of the type of Ve l u t i a sericea Kerremans shows that genus to be doubtfully distinct from Paragrilus .

Characters: Overall, members of the genus are relatively elongate and subcylindrical in form, similar to the genus Agrilus , although members of the P. aeraticollis and P. trifoveolatus groups are more or less flattened dorsally. Colors are typically dark and matte or only weakly shining. Most species are glabrous or inconspicuously setose, although members of the P. aeraticollis group are sexually dimorphic in that males possess areas of conspicuous setae on the front.

The front of the head is typically very convex in dorsal view, usually impressed along the midline, especially deeply so in the P. trifoveolatus group, one of whose members also possesses a round fovea at the base of the depression. The epistoma is typically depressed and relatively narrow between the antennal insertions, but is broader in the P. trifoveolatus group. The ventral margin of the episotoma is produced in some species and is emarginate with more or less sharply acute lateral angles.

The shape and sculpture of the pronotum are the most distinctive features of the species treated here, both in characterizing species groups and in separating species. The genus itself is defined by anterior depressions between the marginal and submarginal carinae which receive the antennae. The posterior angles are usually more or less swollen as a prehumeral callosity and separated from the rest of the pronotal disc by a depression of differing shapes and intensities. In the P. trifoveolatus and P. aeraticollis groups the prehumeral callosity is produced outward and anteriorly to form a ridge above and roughly parallel to the marginal carina. In the P. trifoveolatus group the disc is relatively flattened and has three relatively equal depressions along base which produce an undulating posterior margin. The lateral depressions are relatively weak in the P. rugatulus group and stronger and continuing obliquely to the lateral margins in the P. aeraticollis group.

The elytra are characterized by a strong posthumeral carina which typically extends to just beyond the posterior coxae, but is longer in a few species. This character is shared with a few species of Agrilus (the A. dissimilis group; see below). The elytra are usually more or less transversely rugose and relatively unmodified otherwise, except for a subapical raised callosity in a few species. The apices are usually broadly rounded or subtruncate and slightly emarginate.

The ventral surface is relatively unmodified except for the posterior process of the prosternum and form of the hind coxae. The first ventral abdominal segment is produced anteriorly between the hind coxae and usually has carinae on the lateral margins of the process which border depressions for the hind tarsi when the legs are pulled in to the body. Male genitalia are usually distinctive.

The North and Central American species of the genus can be separated into three groups ­

P. rugatulus group ( P. exiguus (Chevrolat) , P. lesueuri Waterhouse , P. modicus (Solier) , P. rugatulus Thomson , P. transitorius Waterhouse , P. vicinus Waterhouse ) ­ somewhat varied, but generally more cylindrical and characterized by a convex, rugose pronotum with weak prehumeral callosities; known plant hosts of adults are in the genus Sida (Malvaceae) .

P. trifoveolatus group ( P. angulaticollis Waterhouse , P. impressus (Chevrolat) , P. laevicollis Waterhouse , P. tenuis (LeConte) , P. trifoveolatus Waterhouse , P. fallorum n. sp., P. azureus n. sp.) ­ usually more flattened above and characterized by having the pronotum often smoother and with three depressions along base which produce an undulating posterior margin.

P. aeraticollis group ( P. aeraticollis Waterhouse , P. heliocarpi n. sp., P. akersorum n. sp., P. moldenkei n. sp., P. burkei n. sp.) ­ usually more flattened above, the pronotum smooth or rugose, and characterized by males with areas of setae on the front of the head.

Not surprisingly, the species of the P. rugatulus group that are associated with the weedy plant genus Sida L. in the Malvaceae are very common in collections and all described, often multiply. The most poorly known species are members of the P. aeraticollis group, in which 4 of the 5 species are previously undescribed. Known adult hosts in this group are all lianas ( Byttneria Steud. ) or shrubby perennials ( Heliocarpus L., Wissadula Medik. ) found in forest gaps or edges, but not usually in more open second growth. Many are widely distributed, but three of the species in the P. trifoveolatus group apparently have very localized, possibly relictual distributions.