Massocephalus Dallas, 1851

Rider, David A., 2008, Massocephalus stysi, a new species of Pentatomidae (Hemiptera: Heteroptera) from the Philippines, Acta Entomologica Musei Nationalis Pragae 48 (2), pp. 583-590 : 584-585

Massocephalus Dallas, 1851

Massocephalus Dallas, 1851: 195 , 230-231.

Massocephalus: LETHIERRY & SEVERIN (1893) : 118 (catalog); KIRKALDY (1909): 51 (catalog); TANG (1935): 315 (catalog); RIDER (2006): 283 (catalog).

Type species: Massocephalus maculatus Dallas, 1851 , by monotypy.

Redescription. Dorsal surface of head punctate, apex broadly rounded, lateral margins sinuous, antenniferous tubercles visible from above ( Figs. 3, 8). First antennal segment reaching to or nearly to apex of head. Dorsal disk of pronotum sparsely but coarsely punctured, anterior pronotal margin not or only feebly reflexed, anterolateral margins weakly reflexed; pronotal cicatrices obscure, smooth. Scutellum subtriangular, sparsely and finely punctate. Coria finely punctate, R + M vein sinuous, embolar region distinctly wider near apex of R + M vein. Hemelytra covering or nearly covering connexiva. Posterolateral angles of connexiva rectilinear, perhaps slightly toothed, but not spinose.

Ventral surface of head coarsely punctate, antenniferous tubercles bifid in ventrolateral view. Bucculae long and narrow, becoming evanescent near base of head, each with small tooth at anterior end; first rostral segment not reaching base of head. Longitudinal median of thoracic sterna pilose, hairs very short, velvety; prosternum shallowly sulcate mesially, mesoternum nearly flat mesially with slight indication of carina anteriorly, metasternum broader and flatter mesially. Metathoracic scent gland ostiole each extended as long slender ruga, curving slightly forward, becoming acutely pointed apically, reaching to middle of metapleuron or slightly beyond; evaporative areas extensive, spilling onto posterior margin of mesopleura ( Figs. 5, 9). Superior surface of each tibia distinctly sulcate; tarsi three-segmented. Abdomen weakly punctate, trichobothria typically located, but at oblique angle to each other, the more posterior trichobothria also located more laterad; spiracle position unusual, located just mesad of lateral abdominal margin, near the anterolateral corner of each abdominal segment ( Figs. 6, 11).

Comments. Without having studied the genus, RIDER (2006) tentatively catalogued Massocephalus in the Carpocorini ; prior to that, no one had ever formally placed this genus in any known pentatomid tribe. DALLAS (1851) originally described Massocephalus between Coenus Dallas, 1851 (Carpocorini) and Apines Dallas, 1851 (Menidini) . Members of the Carpocorini generally have shorter ostiolar rugae which are not apically acute, while members of the Menidini usually have the basal region of the abdomen produced forward as a small spine or tubercle. Massocephalus maculatus has elongate, apically acute ostiolar rugae, and the base of the abdomen is not produced into a spine or tubercle. STÅL (1876), LETHIERRY & SEVERIN (1893), and KIRKALDY (1909) all listed Massocephalus between Tolumnia Stål, 1868 (Cappaeini) and Palomena Mulsant & Rey, 1868 (Nezarini) . Members of the Nezarini are typically green in color, even after death. The two species of Massocephalus treated in this paper are not green in color, but they do have some characters which may align them with the Cappaeini . In general, members of the Cappaeini are brown in color and have elongate, apically acuminate ostiolar rugae. The color pattern exhibited by these two species of Massocephalus is very similar to several species of Tolumnia . Until a more thorough phylogenetic analysis can be done, it seems best to tentatively place Massocephalus in the Cappaeini .

Massocephalus is easily recognized by the lateral position of the spiracles coupled with the elongate, apically acute ostiolar rugae. The only known pentatomid genera which have the spiracles placed near the lateral abdominal margins are three Oriental or African genera in the tribe Aeschrocorini ( Aeschrocoris Bergroth, 1887 , Geomorpha Bergroth, 1893 , and Tyoma Miller, 1952 ), a single South American genus in the tribe Carpocorini ( Caonabo Rolston, 1974 ), and the very unusual South American genus Stirotarsus Bergroth, 1911 , which was recently placed in its own subfamily ( RIDER 2000). All of these genera either have the ostiolar ruga absent, or very short and ear-like.