Massocephalus stysi, Rider, 2008

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 : 587-590

Massocephalus stysi sp. nov.

( Figs. 2 , 8-11)

Type material. HOLOTYPE: J, PHILIPPINES: LUZON: BENGUET PROVINCE: labeled a) ‘ Baguio Mts. Prov. PI - Feb. ‘26’; b) ‘ F Rivera Coll’; c ) ‘ HOLOTYPE Massocephalus stysi Rider’ ( USNM) . PARATYPE: 1 specimen lacking abdomen, PHILIPPINES: LUZON: BENGUET PROVINCE: labeled a) ‘ Baguio Luzon PI’ ; b) ‘W Robinson donor’; c) ‘ PARATYPE Massocephalus stysi Rider’ ( USNM).

Description. Dorsal surface of head brown to reddish brown, somewhat paler laterally and apically, with a few obscure pale areas on vertex; coarsely punctate except for large impunctate areas just mesad of each compound eye. Apex of head broadly rounded, lateral margins of juga sinuous, subparallel for middle third, apices projecting slightly beyond apex of tylus, but not contiguous anteriorly; antenniferous tubercles easily visible from above ( Fig. 8). Ocelli relatively small, each located 3-4 times its own diameter from adjacent eye. Antennae pale brown, segment I with small obscure darker brown spots, segments II and III slightly reddish, segment I reaching to or slightly beyond apices of juga, length of segment II shorter than segment III.

Pronotum dark brown, posterior disk slightly paler than anterior disk, with large, irregular, quadrate pale spot between cicatrices (dark coloration intruding into posterior margin of spot), anterior one-half to two-thirds of anterolateral margins narrowly pale, a weak, irregular, transverse pale line just behind vertex of head, and humeral angles narrowly pale ( Figs. 2 , 9). Pronotal punctation sparse, fine, becoming somewhat coarser and deeper near humeral angles, cicatrices obscure, impunctate, area anterior to cicatrices uniformly punctate, anterior pronotal margin not reflexed or delineated by submarginal sulcus or row of punctures.Anterior pronotal teeth distinct, slightly recurved posteriorly. Anterolateral pronotal margins nearly straight, distinctly reflexed. Scutellum subtriangular, with an irregular, transverse, white band across base, the white areas are invaded with several dark punctures, apex of scutellum also with relatively large white spot ( Figs. 2 , 9). Hemelytra brown to dark brown, lateral margins not pale, but with distinct, irregular, lateral white spot near middle ( Figs. 2 , 9), punctures fairly uniform, except becoming more shallow and sparse near R + M vein, and small, dense area near apex of each corium. Hemelytral membrane fumose, veins obscure, subparallel. Connexivum nearly concealed by hemelytra, mostly dark with pale markings.

Ventral surface of head brown to dark brown with posterior half or more of bucculae narrowly pale margined, punctures relatively strong, becoming more sparse anteriorly; each buccula with a small tooth anteriorly. Propleura dark brown becoming paler mesially (prothoracic acetabula are completely dark), each lateral margin with narrow, weak, irregular pale band along anterior third, and apex of humeral angles pale. Meso- and metapleural plates dark brown, including acetabula and all stink gland structures; ostiolar rugae relatively short, each reaching at most to middle of metapleuron ( Fig. 10). Legs pale yellowish-white, with numerous brown spots on femora and basal half of tibiae; tarsi, especially segment I, and apices of tibiae brown to reddish brown. Venter dark brown with irregular pale areas along lateral margins ( Fig. 11), especially basally and apically; nearly impunctate, punctures sparse and shallow.

Pygophore (note: the pygophore of the only male specimen available for study is withdrawn into abdomen, and is difficult to see), in ventral view with shallow medial emargination, a lobate projection on each side; parameres in caudal view are sinuous, apices oriented dorsally. Proctiger relatively large, smooth, transversely arcuate, superior ridge anterior to proctiger U-shaped. All structures with numerous long hairs. Female unknown.

Measurements (mm). Total length 9.10-9.35 (9.10); total width across humeri 5.15-5.22 (5.22), across abdomen 5.63 (5.63); medial length of pronotum 2.04-2.07 (2.04). Medial length of scutellum 3.60-3.62 (3.60), basal width 3.03-3.05 (3.03), width at distal end of frena 1.25-1.27 (1.25). Head length 1.97-2.00 (1.97), width 2.57-2.60 (2.57), width between ocelli 0.89-0.97 (0.89), width between eyes 1.71 (1.71), distance from ocellus to adjacent eye 0.41-0.42 (0.41), diameter of ocellus 0.13-0.14 (0.13). Length of antennal segments I-V 0.73-0.78 (0.73), 0.95-0.96 (0.96), 1.45-1.57 (1.45), 1.66-1.67 (1.66), and 1.71 (1.71) respectively. Length of rostral segments I-IV 0.75-0.81 (0.75), 1.28-1.36 (1.28), 1.26, and 1.18 respectively.

Differential diagnosis. This species is easily recognized by shorter ostiolar rugae, and differences in color pattern. The irregular pale band across the base of the scutellum and the irregular pale spot along the lateral margin of each corium are diagnostic.

Etymology. It is with great pleasure that I dedicate this species to Pavel Štys in commemoration of his 75 th birthday. Prof. Štys has contributed much to our knowledge of true bugs.

Distribution. At present, only known from the type locality on Luzon Island, Philippines.

Figures

Figs. 1-2. Habitus. 1 – Massocephalus maculatus Dallas, 1851; 2 – M. stysi sp. nov.