Hylamorpha Arrow, 1899

Hylamorpha Arrow 1899:368.

Type species: Aulacopalpus elegans Burmeister 1844:459, here designated (see discussion below).

Description. Scarabaeidae, Rutelinae, Anoplognathini, Brachysternina. Form: Suboval, wider behind, dorsum convex. Length 11.0–20.0 mm from apex of clypeus to apex of elytra; width 5.5–11.0 mm across elytral humeri. Color dorsally light to dark apple green, sometimes with brown elytra. Head: Surface densely rugopunctate. Frontoclypeal suture distinct. Clypeus with apex broadly rounded, broadly reflexed. Labrum vertically produced with respect to clypeus, with well­defined median tooth, apex broadly rounded. Mentum with anterior edge produced into small tooth that curves into oral cavity. Pronotum: Surface densely punctate to rugopunctate. Base with fringe of dense, moderately long, white setae extending from beneath posterior margin. Elytra: Surface wrinkled and with punctate striae; punctures with scale­like, white setae. Lateral margin membranous from metepimeron to apex. Pygidium: Surface densely rugopunctate, covered by dense, scale­like white setae. Apex at middle with distinct tuft of longer setae. Legs: Protibia tridentate in both sexes, apical spur lacking. Protarsomeres 1–4 each with pair of small spinules on ventral side at apex; protarsomere 5 with distinct, median tooth on ventral side. All claws simple, not split at apex. Unguitractor plate trisetose. Venter: Prosternum lacking keel. Mesometasternal process absent. Propygidium without supraspiracular ridge. Last sternite entire at apex in both sexes, not emarginate.

Diagnosis. The genus Hylamorpha may be distinguished from other genera of the Brachysternina (Aulacopalpus and Brachysternus) by (1) simple tarsal claws (simple or bifurcate in Brachysternus, simple or bifurcate in Aulacopalpus), (2) multisetose unguitractor plates (bisetose in Brachysternus and Aulacopalpus), (3) fourth protarsomeres with two, small, straight spines (spines curved in Brachysternus or straight or curved in Aulacopalpus), (4) apex of last sternite entire in females (entire in Aulacopalpus, emarginate in Brachysternus), and (5) white, scale­like elytral setae (hair­like, slender or thick setae in Brachysternus and Aulacopalpus).

Type Species. Machatschke (1965, 1972) incorrectly designated Aulacopalpus viridis Burmeister, 1844 (not A. viridis Guérin­Méneville 1838) as the type species of the genus Hylamorpha. Arrow (1899) did not designate a type species when he created Hylamorpha. However, A. viridis Burmeister is not an available name. Burmeister (1844:459) simply redescribed A. viridis Guérin­Meneville, correctly attributing A. viridis to Guérin­Méneville (1838:58). Aulacopalpus viridis Guérin­Méneville remains a valid species in the genus Aulacopalpus [see Smith (2002) revision of Aulacopalpus and Jameson and Smith (2002) revision of Brachysternus, both in this issue, for further discussion].

Machatschke’s (1965, 1972) view that the A. viridis of Guérin­Méneville is different than the A. viridis of Burmeister was based on an error by Arrow (1899). When Arrow created the genus Hylamorpha, he described two new species (H. rufimana and H. cylindrica) and transferred one previously described species (A. elegans Burmeister) into Hylamorpha. Burmeister’s (1844) redescription of A. viridis Guérin­Méneville matches Guérin­Méneville’s original description. Arrow (1899) knew the identity of the true A. viridis and characterized it properly as ‘‘... a glabrous insect, clothed beneath with long hair and not decumbent scales, and having the last joint of the maxillary palpus greatly enlarged and channelled along almost its entire length.’’ However, when Arrow erected the genus Hylamorpha for A. elegans, he inadvertently called the species he placed in it A. viridis Burmeister twice and correctly called it H. elegans twice! We know he meant H. elegans because he stated that ‘‘ H. viridis Burm. is the only species of this genus at present described’’ and ‘‘ Aulacopalpus angustus Philippi must be transferred to the genus Brachysternus, with which it agrees in all essential points, having only a superficial likeness to H. ELEGANS ’’ (emphasis ours). Moreover, Arrow’s (1899) description for A. elegans matches his generic description for Hylamorpha whereas the description given for A. viridis Guérin­Méneville and the redescriptions by Burmeister (1844) and Arrow (1899) of A. viridis do not correspond with Arrow’s definition of Hylamorpha. And lastly, Arrow (1901) referred only to H. elegans (not H. viridis) being in the genus Hylamorpha.

Machatschke (1965), apparently recognizing none of this, designated H. viridis Burmeister as the type species of the genus Hylamorpha. Burmeister (1844) properly credited Guérin­Méneville for describing A. viridis, but Arrow (1899) mistakenly attributed A. viridis to Burmeister. Machatschke simply continued Arrow’s mistake. Machatschke’s designation of A. viridis Burmeister as the type species of the genus Hylamorpha is invalid since there is no such species or name.

Accordingly, we designate Aulacopalpus elegans Burmeister as the type species of the genus Hylamorpha. The type species of Hylamorpha is now fixed pursuant to Article 70.3 of the International Code of Zoological Nomenclature (International Commission on Zoological Nomenclature 1999).