Paramimegralla madagascariensis Hennig

Marshall, Stephen A., 2017, Micropezidae (Insecta, Diptera, Acalyptratae) of Madagascar and a revision of the genus Paramimegralla Hennig, Zootaxa 4290 (2), pp. 244-280 : 250-252

Paramimegralla madagascariensis Hennig

Figs 7 ̄13

Paramimegralla madagascariensis Hennig 1937: 47 ; Verbeke 1951: 101; Steyskal 1980: 581; Barraclough 1992: 5.

Redescription. Length 13̄ 16 mm. Ground colour mostly blue–black, thorax brown anteroventrally but mostly black and densely silver or golden microsetulose, with microsetulosity creating a narrow lateral strip and medial golden strip dorsally, notum otherwise silvery pruinose.

Head with frons broad, ridged longitudinally; epicephalon and outer parts of orbital strips shining; frontal vitta velvety black pruinose, narrowing to a thin groove anteriorly, broad and parallel-sided posteriorly. Paracephalon elevated above level of occiput. Occipital suture shining reddish brown, expanded posteriorly, back of head also with a central reddish spot, ventral third of head, including face, clypeus, palpus, gena, and lower third of postocciput yellow. Head chaetotaxy complete, with 2 frontal setae. Parafacial silvery dorsally and ventrally, black at middle. Palpus broad. Clypeus bare, shorter than face plus lunule, upper margin medially produced into a distinct triangular projection. Length of first flagellomere subequal to width.

Thorax with scutellum silvery, scutum mostly densely silver microsetulose, central and lateral strips golden microsetulose. Proepisternum with short, inconspicuous ventral setae. Proepimeron shining posterodorsally, continuous with shining anterodorsal corner of anepisternum, area behind procoxae microsetulose. Legs mostly yellow, mid and hind femora of males with a distal black ring (sometimes incomplete on hind femur), mid and hind femora of females with basal and distal black rings. Fore femur of females with a broad black ring, males with an indistinct and incomplete fore femoral ring. Fore tibia and basal half of fore tarsomere one dark brown to black, fore tarsus otherwise white except for the slightly brown–tinged apical tarsomere. Mid and hind tarsus reddish brown, apices of tibiae dark. Hind femur slightly flattened, hind tibia with outer surface sulcate on basal quarter.

Wing uniformly darkly infuscated except for a transverse preapical pale band. Anal cell bare, CuA2 sinuate and almost in line with dm̄cu, distal angle 30̄35 °.

Abdominal syntergite 1+2 slightly humped and silvery at junction between T1 and T2; T2, T3 and T4 faintly silvery anteriorly and posteriorly; pleural membrane in both sexes black dorsally and white to yellow ventrally, black area extending ventrally on P3 of female. Oviscape black with orange apex, microsetulose on basal half and bare on distal half. Spermathecae on two ducts of similar length, thinner duct leading to very small spermatheca generally similar in structure to paired spermathecae, thicker duct distally expanded and branching into two long basally swollen, convoluted and distally tuberculate stems each ending in a subspherical spermatheca with a deep apical invagination (sometimes everted). Bursa copulatrix dorsally dense and rugose, ventral receptacle short with a smooth cap. Male with genital fork (S5) with very short distally incurved arms with apical cluster of stout, dark, closely packed teeth. Unlike all congeners except P. zinzala , the phallic plate extends far beyond the apex of the phallapodeme, with the basal part of the phallus forked and correspondingly extended posteriorly beyond the point of entry of the ejaculatory duct, extended part of phallic plate half as long as distiphallus. Distiphallus broad and short, basal part ending in a simple phallic bulb with a broad posterior loop; distal part of distiphallus separated from phallic bulb by a dorsal notch, exceptionally short, barely longer than phallic bulb, ending in a weakly differentiated but apically cupped glans. Blade of ejaculatory apodeme smaller than epandrium but much larger than sperm pump, ejaculatory apodeme including sperm pump subequal in length to epandrium.

Type material. Holotype (♀, BMNH, see comments) " BMNH 1868 4", W.W. Saunders. Specific locality within Madagascar not given.

Material examined (three specimens pinned, others in alcohol; all CAS) Analalava, 17°41'35.5"S, 49°27'37"E, 75m, M. Irwin, R. Harin'Hala Malaise traps, 2008 (3̄ 9.i, 11̄ 18.i, 18̄ 25.i, 22̄ 29.ii, 16̄ 23.v, 23̄ 30.v., 13̄ 20.v, 20̄ 27.vi, 22̄ 29.viii, 29.viii ̄ 26.ix, 26.ix ̄ 4.x; all of these Malaisētrapped specimens are female except for one male from 3̄ 9.i.08). Two pinned specimens from Analalava were sequenced (labelled MYCRO0035̄15, 36̄15).

Comments. This species, apparently endemic to northern Madagascar, was previously known only from the female holotype, which lacks antennae, tarsomeres and hind tibiae. The holotype was redescribed by Barraclough (1992). The female specimens treated here as P. madagascariensis match the type description in most details but the notum is mostly shining blue black, and the orbital setae are black. The type has pale orbitals, and a mostly dark brown thorax. Since the unique type was collected in 1868 it seems likely that the brown color is the result of fading.

The male specimen treated here as P. madagascariensis differs from the females in having only a single, distal, black band on the mid and hind femur. A male and a female were sequenced for CO1, and were identical, thus confirming that this is indeed intersexual variation. The only similar species is the sister species, P. zinzala , an eastern forest species with similar wing pigmentation and a similarly short–armed genital fork. But P. zinzala differs in leg and head pigmentation, wing venation, and many details of the phallic complex.

Figures

FIGURES 7 – 13. Paramimegralla madagasCariensis Hennig. 7. Female specimen; 8. Spermathecae and associated structures; 9. Lateral view of bursa copulatrix to show ventral receptacle; 10. Male specimen; 11. Sternite 5, synsternite 6 + 7; 12. Head, anterolateral; 13. Male terminalia, left side.