Melander, A.L.

Proceedings of the Hawaiian Entomological Society

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Vol. XIV# No. 3, March, 1952 419Drapetis insularis, a new Species from Oahu (Diptera: Empididae)By A. L. MELANDERRIVERSIDE, CALIFORNIAOnly one species of Empididae has been recorded from the HawaiianIslands, which I described as Chersodromia hawaiiensis, in 1938 ("Proceedings," 10: 57). Specimens were found about the excavation holes ofcrabs on the beach of Hanauma Bay, Oahu. The present species, alsobelonging in the sub-family Tachydromiinae of the Empididae, was submitted by Dr. D. Elmo Hardy, who reports that it was abundant, flyingwith Milichiella lacteipennis (Loew) over compost at the dairy farm onthe campus of the University of Hawaii. He sent me 33 specimens foridentification, and as the species is undescribed I am glad to present thefollowing description.Drapetis (Crossopalpus) insularis, Melander, sp. nov.Length 2.5 mm. Entirely shining black or blackish in ground color. Front nearlyparallel-sided, more or less brownish tomentose; face linear; occiput densely paleochraceous-pollinose, the orbits entirely densely cinereous; cheeks deep, shining blackbelow the eye-margin; two long ocellar bristles, nearly as long as the vertical pair;antennae black, the basal joint brownish, with a long bristle beneath, the outer jointrounded triangular, as long as deep; the preapical bare arista about four times the lengthof the antenna; proboscis black, palpi light brown. Thorax broad, round in dorsal view,shining black, the dorsum with slight aeneous lustre, covered with fine short dark hairs,four small dorsocentrals, the presutural very minute, scutellum with six bristles, theintermediate pair long; two notopleural, one supra-alar bristle. Abdomen short andbroad, shining black, the hairs dull yellowish and sparse, becoming longer and darkeron the apical segments; pygidium large, rounded, closed, without evident appendages.Legs mostly shining black, the anterior knees, base of hind tibiae, coxae and trochanterscastaneous, the hind tibial lappet heavily fulvous pubescent which continues on theanterior side of the metatarsus, the lappet two-fifths as long as the metatarsus, pubescence of legs scattered, not conspicuous, blackish; middle femora with a small preapicalbristle on the anterior side, hind femora with two preapical bristles, anterior tibiaeeach with two preapical bristles, hind tibiae with long antero-flexor bristle near themiddle and another halfway to the tip, three smaller apical bristles opposite the lappet.Wings clear hyaline, base of costa with a long black bristle, veins narrow and piceous,costal ratio 3:2:1, apical cell narrowed at apex, the fourth vein nearly straight, itsbasal half whitish, the anterior crossvein nearly at middle of the discal cell; halterespale yellow.11 males and 22 females. Honolulu, Oahu; D. Elmo Hardy and H. A.Bess, collectors. October-November, 1951. Type and allotype sent to theUnited States National Museum. Paratypes divided between the author'scollection and that of the University of Hawaii. Dr. Hardy writes that hehas taken several dozen additional specimens at the type locality.E. O. Engel separates the subgenus Crossopalpus Bigot in that its species have the cheeks broadly extending beneath the eyes and two ocellarsare present. There are but few dark-legged species of Crossopalpus (=Eudrapetis Melander) with which insularis might be confused. They maybe differentiated by the accompanying table.420 Proceedings, Hawaiian Entomological Society1. No lappet on the hind tibiae, or at most a vestige of one 2A distinct lappet at apex of the hind tibiae 42. Halteres pale yellow 3Halteres dusky; pleura shining; tibiae merely pubescent (Europe) humilis Frey3. Hind tibiae with a series of about five extensor bristles; pleura shining; fourthvein nearly straight (Europe) curvipes MeigenHind tibiae without bristles; pleura more or less pollinose; fourth vein undulate(Europe) flexuosa Loew4. Hind tibiae with long fine extensor bristles and flexor pubescence 5Hind tibiae without long extensor bristles 65. Hind femora with four pale flexor bristles (Europe, Africa, Formosa) (= cenes-cens Bezzi) pilipes LoewHind femora with one black flexor bristle (western United States). ..nitida Melander6. Hind tibiae with a few short stiff bristles at apex; mesonotal pubescence dark 7Hind tibiae without a cluster of apical bristles; a small presutural dorsocentralbristle present, mesonotal pubescence pale (Europe, Africa, Asia)- aenescens Wiedemann7. Hind tibiae without long bristles; no presutural dorsocentral; halteres dark(Europe) aterrima CurtisHind tibiae with two long flexor bristles; a small presutural dorsocentral; halteres pale (Hawaii) .insularis, n. sp.Of the Pacific Island species of Crossopalpus, brevicula Melander (=brevis Bezzi, preoccupied) has the fifth vein apically faint, and pubicornisBezzi has the occiput shining black while the third antennal joint iselongate and pubescent beneath. These two species occur in Formosa andhave yellow legs. Drapetis crockeri Curran, from the Cook Islands, alsohas yellow legs and the dorsal segments of the abdomen are marked withreddish.

Drapetis insularis, a new Species from Oahu (Diptera: Empididae)

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Drapetis insularis, a new Species from Oahu (Diptera: Empididae)

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