Lasiochilus marianensis, Usinger, 1946

Usinger, Robert L., 1946, Hemiptera Heteroptera of Guam, Insects of Guam II, Honolulu, Hawaii: Bernice P. Bishop Museum, Bulletin 189, pp. 11-103 : 52-53

46. Lasiochilus marianensis , new species.

Relatively small, elongate-oval, pale at bases of coria and cuneal fractures, second antenna! segment scar~ely shorter than width of head across eyes. Male genital clasper, as seen from above, widened apically, with only a feeble basal ridge and without an entirely distinct apical lobe. Rostrum reaching to level of front margins of middle coxae.

Head slightly longer than broad across eyes, 17: 14; anteocular portion a little longer than an eye, 6.5: 5, and scarcely broader than length of an eye, 5.5: 5; eyes relatively small, one third as wide as interocular space; disk smooth, shining, faintly rugose between ocelli and with a posteriorly arched impression between eyes. Tylus transversely rugose near middle. Disk with several long erect hairs located along inner margins and behind ocelli, between eyes, and anteriorly. Rostrum, when stretched to its fullest length, surpassing middle of mesosternum, reaching level of front margins of middle coxae; proportion of segments one to three as 6: 16: 9. Antennae one third longer than width of pronotum across humeri, 37: 27, first segment reaching about to apex of head, second segment scarcely shorter than width of head including eyes, 13: 14; proportion of segments one to four as 5: 13: 9: 10.

Pronotum two thirds as long as head on median line, over twice as broad as long, 27: 12, about half as wide at anterior margin (measured across postocular part of head) as at humeri, 13:27; sides feebly arcuate or almost straight posteriorly, broadly and strongly rounded only at anterior angles. Disk smooth, polished, with faint submarginal wrinkles anteriorly, a longitudinal impression faintly indicated on posterior half of large, moderately elevated median area, the short, flattened posterior area distinctly, transversely wrinkled. Middle of disk with only a few widely separated, backwardly directed hairs, becoming denser posteriorly and very dense along lateral margins, the sides with about four much longer, erect hairs and one of these on either side near anterior margin. Scutellum glabrous on basal fourth medially, dull and clothed with curved, subappressed hairs elsewhere.

Hemelytra exceeding tip of abdomen, the clavus, corium, and cuneus impunctate, uniformly clothed with moderately long, curved, subappressed, backwardly directed hairs. Embolium not quite as wide near cuneal fr.acture as inner portion of corium at the same level. Membrane dull except for shining narrow basal stripe.

Under surface with thoracic pleura naked, sterna with short hairs. Abdominal venter clothed with short, backwardly directed pubescence and with longer, erect hairs posteriorly and laterally. Ostiolar canal sinuate, curved slightly forward on hind margin basally and then backwardly rounded, not reaching postero-lateral margin. Legs shining, beset with scattered hairs, the front femora a little more than one third as thick as long, 6: 16, hind femora slightly less incrassate and middle femora even less incrassate.

Male genital clasper, as seen from below (described from the Machanao paratype), sinuate, broad at base and then slightly bent forward and tapering to subacute apex which is bent feebly outward. Seen from above, the tapering portion is gradually broadened into a blade-like organ, one fifth as broad at apical fourth as entire length of clasper and rounded at apex.

Color brown, the head at apex, basal third of corium, extreme outer base of olavus, and cuneal fracture paler, ochraceous. Apical margin of membrane with a fringe of minute white hairs. Rostrum, trochanters, apices of femora, tibiae, and tarsi testaceous. Base and apex of second antenna! segment often pale and last two segments dirty stramineous.

Size: length, male, 2.25 mm., female, 2.4 mm.

Holotypemale,allotypefemale, Mt.Alifan, May 26,inrottenpapayalog, Usinger ; one paratype, Machanao, June 30, beating dead leaf-covered branches, Usinger ; one paratype, Piti, June 10, at light, Swezey .

L. marianensis belongs to the subgenus Dilasia and differs in color, antennal, and rostral characters from the East Indian species elongatus Poppius, bivitta.tus Poppius and fruhstorferi Poppius. This last has been reported from Samoa [Knight, Ins. Samoa 2(5): 228, 1935] but the identification must be regarded as provisional because no authentic material w,;1. savailable for comparison and the antennal proportions were noted as different. Such identifications based upon degree of correspondence to an inadequate description are of little value in this group. Reuter and Poppius evidently failed to note the striking differences existing in the form of male genital claspers in Lasiochilus . Furthermore, they considered denigratus (White) to be a single variable species with decolor as a variety. Kirkaldy (Haw. Ent. Soc., Proc. 1: 196-197, 1908) showed that each of the main Hawaiian islands has a distinct species of Lasiochilus . Distant (Linn. Soc. London, Trans. 16: 184-186, 1913) found an amazing number of endemics in the Seychelles and a large number of endemics may be expected among the numerous islands of Polynesia and Micronesia. Denigratus and other Hawaiian species differ from marianensis , swezeyi , and the undescribed species before me from Fiji in the large, inwardly bent apical lobe of the male genital clasper.