Brues, C.T.

Proceedings of the Hawaiian Entomological Society

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154apex growing very minute; the whole femur unusually slender.Length 8-10 mm.The abdominal petiole is unusually well set off from the gaster,with strongly bulging sides and is quite different in this respectfrom the condition usually prevailing in Leucospis. One other species, L. muiri Brues, from Laloki, Papua, shows a tendency in thisdirection in the male, but the sides are much more nearly parallel.Dentition of hind femur of Leucospis antiqua Walker, $. Highly enlarged.On account of the unusual shape of the abdomen the male ofLeucospis antiqua resembles in a very striking way a vespid wasp,a resemblance which is heightened by the color pattern. The wasp,which is also practically of the same size of the Leucospis has beenidentified by Professor Joseph Bequaert as Pachymenes quodi(Vachal).A Species of Phoridae Bred in Hawaii From the ImmigrantAfrican Land Snail (Achatina Fulica)BY CHARLES T. BRUESBiological Laboratories, Harvard University.(Presented by Mr. Swezey at the meeting of December 22, 1941)In various parts of the world there are numerous species of smallflies of the family Phoridae that have been found associated withterrestrial gastropod mollusks. The majority of these undoubtedlydevelop in snails already dead from some other cause; some probably occur in the slimy exudate of living hosts, and there is reasonProc. Haw. Ent. Soc, Vol. XI, No. 2, July, 1942.155to suspect, but without conclusive proof, that some may be trueinternal parasites of living snails. Mr. E. H. Bryan, Jr., sent merecently four specimens of a very small, winged species that werebred by one of his associates at B. P. Bishop Museum, YoshioKondo, from a dead example of the large African snail, Achatinafidica. After a careful examination of four specimens, includingboth sexes, it appears that this phorid is undoubtedly undescribed.It is quite similar to the European Megaselia pygmaea, known tooccur also in a number of widely separated regions, but is obviouslydistinct. A further search to identify it with any other species ofthis large, cosmopolitan genus has failed, and though there is avery considerable chance that its original provenience is not Hawaii,it seems appropriate to describe it at this time since we know something of its habits and structurally it is easily identified.Megaselia (s. str.) biformis sp. nov.$ . Length 1.4 mm. Black, with the thorax reddish brown above and distinctly lighter on the pleurae and coxae; abdomen with the basal fourtergites rather broadly margined with yellowish white behind. Legs testaceous or luteous; hind femora black at apex and their tibiae blackened at theextreme tip. Antennae reddish brown; palpi light yellow. Front approximately as high as wide; four postantennal bristles of equal size, those of theupper pair twice as far apart as those of the lower pair; antial bristles midway between the upper postantennals and the eye-margin, well below thelowest lateral bristle which is close to the eye; middle row of frontal bristlesequidistant, the median pair higher than the lateral ones and twice as far fromthe upper postantennals as from the ocellar bristles. Surface not shining,glaucous. Antennae small, with weakly pubescent arista; palpi small, withmoderately strong bristles. Propleura with a bristle at its upper angle,another next to the coxa and a scattering series of much weaker ones alongthe hind margin between those. Mesonotum moderately shining, with a singlepair of dorsocentral bristles. Scutellum with four large marginal bristles.Mesopleura entirely bare. Abdominal tergites fully formed, none of themnarrowed, the second without any bristly hairs at the sides; second to fifth ofapproximately equal length, their posterior margins practically straight,except the fifth which is broadly rounded. Middle and hind tibiae with asingle row of bristles lying inside the hairseam; those of the middle pairweak; those of the hind tibiae very weak on the basal third but longer beyondwhere their length is equal to two-thirds the width of the tibia. Wings ratherlong and narrow; costa distinctly less than one-third the wing length(17:57), its fringe short at the base, but much longer toward apex wherethe bristles are as long as the second vein. First section of costa twice as longas the second and third combined, the third section very short as the cellbetween the second and third veins is extremely minute; fourth vein curvedupwards at its apical third, but nearly straight elsewhere, fifth vein indistinctly sinuate, almost straight; sixth more clearly sinuate; sixth vein distinct.Halteres pale yellow.$ . Similar to the female, but somewhat darker in color, especially theantennae. Scutellum with only two bristles, the lateral pair reduced toextremely minute hairs. Wings somewhat broader. Costa exactly one-thirdas long as the wing (15: 45) ; first section slightly less than twice as long asthe second and third combined.156Type and three paratypes (two females and one male) fromHonolulu, Hawaii, February, 1941, reared from a dead specimenof Achatina fulica (Y. Kondo).There are a few species of Megaselia in which the female possesses four large scutellar bristles while the male has the anteriorpair reduced to small hairs. None of the forms of this type whereboth sexes are known resemble the present species at all closely inother characters. Aside from this peculiarity M. biformis differsfrom M. pygmaea Zett. by the equal postantennal bristles and bythe wide, completely formed abdominal tergites, which also serveto distinguish it from M. latericia Schmitz. The European M. pyg-maeoides Lundb. likewise differs by its unequal postantennalbristles as well as in the length of the costal vein. From M. angus-tiata Schmitz from the Canary Islands it is distinct by the equallystrong postantennal bristles and much shorter costal vein. The palehalteres serve to distinguish it from several other species with veryshort costal vein. Several other forms associated with mollusks,like the African M. nvichaelis Schmitz, are structurally not at allsimilar and the same is true of M. curtineura Brues from the Philippines which is superficially similar on account of its short costalvein. The last species was found breeding in culture media whichwere presumably contaminated with fungi or bacteria.Senior-White has described Megaselia achatinae (Spolia Zeylan-ica, vol. 12, p. 401 (1924)) as bred from a dead Achatina snailfrom Ceylon. Unfortunately his description is utterly inadequate toplace the species, although from the size and color it may be theubiquitous M. xanthina Speiser which is widerspread and abundantin this region.

A Species of Phoridae Bred in Hawaii From the Immigrant African Land Snail (Achatina Fulica)

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A Species of Phoridae Bred in Hawaii From the Immigrant African Land Snail (Achatina Fulica)

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