Halovelia marianarum, 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 : 98-100

94. Halovelia marianarum , new species ( fig. 27 ).

Male: rather evenly oval in outline. Pubescence very dense, brown to gray. Body subflattened beneath and only feebly convex above.

Head a little broader across eyes than long, 20: 17; produced in front of eyes for a distance greater than length of an eye, 8: 7; eyes small, about one fourth as wide as interocular space, 3.5: 13. Vertex rather strongly convex. Rostrum slightly exceeding apices of front coxae. Antennae about two thirds as long as body, 38: 58; proportion of segments one to four as 12: 8: 8: 10.

Pronotum less than one third as long at middle as head, 5: 17; broader laterally, the posterior suture slightly sinuate at middle and distinctiy sinuate sublaterally. Meso and metanota together as long as their width measured between impressed lines within lateral carinae.

Male genital claspers long, extending upward beyond upper apex of genital segments and there crossing, beyond which they are curved and tapering. Clearly visible from above and behind.

Front legs relatively short, the femora as long as head, one fourth as thick at middle as long, tibiae scarcely shorter than femora, 16: 17, enlarged apically and bearing a prominent comb on under side, the comb slightly exceeding apex of tibia and longer than basal portion of tibia before comb, 27: 23. Tarsus scarcely half the length of tibia, 7.5: 16; first segment narrow at base, a little widened apically, the second enlarged, over three times as long as first, 18: 5. Middle legs long, the femora three fourths as long as body, 42: 58; tibiae scarcely shorter than femora, 41: 42; tarsus about two thirds as long as tibia, 28: 41; the first segment only slightly longer than second, 15: 13. Hind legs proportioned as follows, 23: 18: 3.5: 5.

Female: much larger and more robust; proportions of head and antennae as in the male. Thorax strongly convex above connexiva, much more strongly elevated than in the male, nearly vertical. Rostrum slightly shorter, reaching to apices of front coxae. Antennae a little more than half as long as body, 46: 87. Proportions of front femora, tibiae, and first and second tarsal segments, 25: 22: 2: 8.5; intermediate legs, 62: 60: 25: 19; posterior legs, 33: 27: 5: 8.

Color of male brown anteriorly and ventrally, the appendages shining, brownish black. Coxae, trochanters, and middle of venter paler brown. Base of vertex brownish ochraceous at middle. Female with base of head ochraceous.

Size: male, length 1.5 mm., width 1 mm.; female, length 2.25 mm., width 1.2 mm.

Holotype male, allotype female, and 35 paratypes, Finile, May 28, Usinger ; nine paratypes, Asanite Bay, June 25, Usinger . Found near the rocky coral shore, usually within or around 3- or 4-foot coves or embayments. They occur singly or in threes and fours rather than in large numbers. Several pairs were captured in copulation.

Esaki (Tenthredo 1: 355, 1937) records his New Guinean species bergrothi from the Carolines and from the coast of Rota Island, only a few miles away from Guam. It seems unlikely that two closely related but distinct species of marine insects, one of them presumably widespread, would occur so close together in the Marianas Islands, but my specimens do not agree with Esaki's original description of bergrothi (Hist.-Nat. Mus. Nat. Hung., Ann. 23: 161, figs. 12 , c-e, 1926). H. bergrothi was captured "on the surface of a few cupfuls of rain-water, which was accumulated on a very thick root of a tree which laid about a half meter high from the earth in the half-dark shade of a dense wood", on Seleo, a coral island near New Guinea. I have seen a closely related species fromFiji.

In Esaki's key (op. cit., p. 164) marianarum runs to papuensis but the head is much longer than broad between the eyes. It may be that the first dichotomy should read "Head nearly as long as broad across eyes." In any case, marianarum is closest to bergrothi , agreeing with that species in the subequal second and third antenna! segments and in the strongly convex mesonotum. Bergrothi differs, according to Esaki's description and figures, in the longer meso and metanota, front tarsus not shorter than half the length of tibia, first segment of middle tarsi one and one half times as long as second, and hind tarsus slightly longer than half the length of tibia. The male of bergrothi is longer and more slender (1.8 mm. by 0.8 mm.), and the female is considerably longer and slightly broader (2.7 mm. by 1.3 mm.).

1Hale (South Austr. Mus., Rec. 3: 204, 1926) calls attention to the remarkable anterior tibial comb which occupies three sevenths of the length of the anterior tibia in maritima Bergroth. Although Esaki quotes Hale's work he ignored this important character in his description.

I consider that the subfamily Haloveliinae Esaki belongs in. the Veliidae where Bergroth (Ent. Mo. Mag. II, 4: 277, 1893) originally placed it and whereHalealsoplacedit. Thelateralthoracicscentglandsofthe Veliidaeare distinct and functional (judging by small globules of hardened exudate at the openings in some specimens) in Halovelia , whereas gerrids have a single scentgland opening (omphalium) at the middle of the metasternum.

Figures

FIGURE 12.-Cardiastethus minutissimitS: a, dorsal view of male; b, head and antennae of female.

FIGURE 27.-Halovelia marianarum: a, dorsal view of male; b, detailed enlargement of inner face of front tibia showing tibial comb occupying slightly more than aP,ical half of tibia; c, dorsal view of female.