Drosophila pihulu Magnacca

Magnacca, Karl N. & Price, Donald K., 2012, New species of Hawaiian picture wing Drosophila (Diptera: Drosophilidae), with a key to species, Zootaxa 3188, pp. 1-30 : 24-25

Drosophila pihulu Magnacca , new species

Fig. 8

Diagnosis. This species is nearly identical to D. assita of Hawai‘i and D. montgomeryi of O‘ahu. It is readily separated from the sympatric D. vesciseta by the leg ciliation and yellow palpi, and from both it and the remaining members of the vesciseta subgroup except D. montgomeryi of O‘ahu by possessing a distinct dark brown stripe along the upper edge of the anepisternum. In D. pihulu the posterodorsal cilia of the male front tibia extend the full length of the segment, while in D. montgomeryi they cover only the basal 2/3.

Description. Male. Head. Front yellow; ocellar triangle and orbits brown. Fronto-orbital setae normal, anterior reclinate nearly as long as the proclinate and about 2/5 as long as the posterior reclinate. Face and gena white to pale yellow except for a small brown spot below the eye. Antenna entirely pale yellow; arista with about 6–8 dorsal and 2–3 ventral rays in addition to the apical fork, and numerous long median branches. Two strong oral vibrissae, the upper one stronger; other oral setulae small and hairlike. Palp yellow, broad and flattened, broadest near middle, rounded apically, with a prominent black apical seta, about half as long as the palp. Labellum and mentum yellow. Thorax. Mesonotum and scutellum entirely yellow to rufous, without dark markings. Pleura largely yellow to rufous, with three prominent dark marks—a narrow stripe along the dorsal margin of the anepisternum; a square mark on the anterior margin of the anepimeron; and posterodorsally on the katepisternum, within the area bounded by the katepisternal seta. Anepisternum and lateral metanotum (above spiracle and haltere) usually tinged with brown to a greater or lesser degree, sometimes almost entirely brown. Two pairs of strong dorsocentral setae, the anterior about 3/4 as long as the posterior. Legs. Entirely yellow. Front tibia with a basal cluster of about 6–7 very long and 7–8 shorter curved cilia, and rows of about 10–12 anterodorsal and 12–15 posterodorsal cilia along its entire length, about equal in length; dorsal surface with about 20 shorter cilia in an irregular row. Front basitarsus about 3/5 as long as tibia, with about 6 long anterodorsal and 8 shorter posterodorsal cilia. Distitarsus usually lacking elongate cilia, sometimes with one pair on the second segment. Wings. Marks present at base, over ends of major veins, dm-cu crossvein, and medially on R2+3; the last elongate, twice as long as high. Basal mark moderately sized, but not reaching r-m crossvein. Costal fringe extending about 3/5 the distance between apex of R2+3 and R4+5. Abdomen. Each segment with yellow spots anterolaterally, remainder dark brown. Cerci slightly longer than high. Genitalia not dissected.

Female. Unknown.

Types. Maui: Holotype 3, Hana‘ula, Pohakea, 3400 ft., 13.iv.1971, S.L. Montgomery (UHIM); paratypes: Moloka‘i: 73, East ‘Ōhi‘a Gulch, 2000 ft., 24.i.1973, R84, S.L. Montgomery (UHIM).

Distribution and ecology. Maui and Moloka‘i. Reared from rotting bark of Urera glabra (‘ ōpuhe , Urticaceae ).

Etymology. From the Hawaiian pihulu , hairy or fuzzy, referring to the abundant ciliation of the legs.

Discussion. The type locality cannot be found precisely, and it is uncertain if the species still occurs there. Much of the mesic habitat around Hana‘ula appears to have been lost since collections were made in the 1970’s, but Urera may persist in wetter parts of gulches where native vegetation is still intact. All other members of the vesciseta subgroup (with the exception of D. ambochila ) are now extremely rare.

Figures

FIGURE 8. Drosophila pihulu. A. Right front leg of male, dorsal view. B. Wing.