Myolepta pazukii Gilasian & Reemer

Gilasian, Ebrahim, Reemer, Menno & Parchami-Araghi, Mehrdad, 2016, Description of Myolepta pazukii Gilasian & Reemer sp. nov. (Diptera: Syrphidae) with notes on the Iranian species of Myolepta Newman, Zootaxa 4103 (3), pp. 276-282 : 277-280

Myolepta pazukii Gilasian & Reemer sp. nov.

( Figs 1–7 )

Diagnosis. Myolepta pazukii sp. nov. differs from M. difformis (Strobl) , M. dubia , M. trojana and M. vara (Panzer) in the pointed inner projection of the hypandrium ( Fig. 6 ) (with blunt, rounded inner projection in the latter species). It can be separated from M. obscura by the orange colouration of the abdomen (wholly black in M. obscura ). It differs from M. potens (Harris) and M. mada Reemer & Hauser in its narrow black median facial stripe ( Fig. 4 ). The shape of the hypandrium (nearly parallel or slightly converging laterally to apex in ventral view) and the pilosity of the mesonotum (yellowish-white erect hairs) ( Fig. 2 ) are similar in M. pazukii sp. nov. and M. nigritarsis , but M. pazukii differs in the orange posterior margin of abdominal tergites 3 and 4 (entirely black in M. nigritarsis ) and the anterolateral orange spots on tergite 3, which do not reach the posterior margin of the tergite. Additional differences between M. pazukii and M. nigritarsis are listed in Table 1 . The colour pattern in legs and abdomen ( Fig. 5 ) is shared between M. pazukii sp. nov. and M. carthaginiensis Reemer & Hauser , but M. pazukii differs from M. carthaginiensis in the following characters: lateral margins of hypandrium in ventral view nearly parallel ( Fig. 7 ) (convex in M. carthaginiensis ) and anterior half of mesonotum with yellowish-white erect hairs instead of golden appressed hairs.

Description. MALE. Body length 7.2 mm ( Fig. 1 ). Head ( Figs 3–4 ). Eye contiguity about 1/2 as long as ocellar triangle; face at level of median facial tubercle about 0.4 times as wide as total width of head; facial tubercle rounded; face black, predominantly pruinose, except for a median narrow, shining, black stripe confined to the facial projection and upper margin of mouth and a shining, black lateral portion of the face below the eyes; gena pruinose with a narrow, ventral, shining black stripe; frons shining black, anterior portion of frons mostly pruinose (except posterior margin of lunule) meeting pruinosity of face laterally, width of pruinosity along eye margin at level of antennae much wider than scape; posterior portion of frons bare and shining black; lunule dark brown; ocellar triangle with a few yellowish-white hairs visibly longer than the triangle; scape, pedicel and arista brown, third segment of antenna orange, 1.4 times as long as wide; arista about 1.8 times as long as third segment of antenna; occiput pruinose except for a narrow, shining black stripe along the postocular margin, dorsally; prementum brown; palpus absent. Thorax. Mesonotum shining black except for pruinose spots close to postpronotum; mesonotum with uniform, short, yellowish-white, erect hairs ( Fig. 2 ); postpronotum pruinose on anterior half; postalar callus shining black; scutellum shining black, heavily punctuated, with yellowish hairs; mesopleuron shining black except for proepisternum and anterior part of proepimeron; anepisternum, median part of katepisternum, anepimeron and katepimeron with yellow hairs. Legs. Fore coxa predominantly pruinose; dorsal half of hind coxa pruinose; mid coxa and ventral half of hind coxa shining black; trochanter shining black; femora shining black, thickened and entirely with yellow hairs, fore and mid femora with two rows of ventral spines on almost apical half, hind femur with two rows of distinct ventral spines reaching basal half as a field of bristles; tibiae shining black, basal third and apex orange and with yellowish hairs, mid tibia with a transverse row of ventroapical black bristles; tarsi orange except dark tarsomeres 4–5, with dorsal and ventral yellowish hairs; pulvilli yellowish; claws dark brown, basal third orange. Wing. Hyaline; veins mostly dark, yellowish in basal third, veins C and R1 yellowish in basal half of pterostigma; wing predominantly with microtrichiae, base of costal, 1st basal (br), 2nd basal (bm) and anal cells bare; calypter whitish; halter yellow. Abdomen ( Figs 5–7 ). Entirely with yellow hairs; tergite 1 mostly black except lateral orange portion; tergite 2 orange with median longitudinal black stripe reaching posterior margin; tergite 3 predominantly black with a pair of anterolateral triangular orange spots ending short of the posterior margin; posterior margin of tergite 3 orange; tergite 4 black, densely punctuated and posteriorly orange ( Fig. 5 ); pregenital tergites black; sternite 1 mostly black, posteriorly orange, entirely dusted and with long yellow hairs; sternite 2 orange, dusted and with short yellow hairs; sternites 3–4 predominantly black, but anterior margin of sternite 3 and posterior margin of sternite 4 orange, both sternites dusted and with short hairs; hypandrium in lateral view with an pointed inner projection ( Fig. 6 ); lateral margins of hypandrium nearly parallel in ventral view ( Fig. 7 ). FEMALE. Unknown.

Type material. Holotype ♂, IRAN, Fars province, Arjan Biosphere Reserve, 29˚33'26.7"N 051˚55'10.1" E, 1930 m, 10.iv.2006, leg. E. Gilasian.

Etymology. This new species is dedicated to Mr. Ali Pazuki (former head of the Insect Taxonomy Research Department, Iranian Research Institute of Plant Protection) in recognition of his contribution to insect taxonomy in Iran.

Discussion. The similarity between M. pazukii sp. nov. and M. nigritarsis is based on the shape of the lateral margins of the hypandrium in ventral view (compare Fig. 7 with Fig. 12e in Reemer et al. 2004: 576) and the pilosity of mesonotum. The most obvious differences between these two species are found in the colouration of the abdomen and leg, which spark the impression that these taxa are colour varieties of the same species, possibly originating from climatic differences between Iran (whence M. pazukii sp. nov. is described) and western Europe and Turkey (from where M. nigritarsis is known). However, the additional morphological characters listed in Table 1 do not support this idea. Besides, if M. pazukii sp. nov. would be a pale colour variety of M. nigritarsis with partly yellow legs and yellow posterior margins of tergites 3–4, then it would be quite unexpected that at the same time the yellow spots on tergite 3 are much smaller than in M. nigritarsis . For these reasons, we believe that M. pazukii represents a distinct species.

Figures

FIGURES 1 – 4. Myolepta pazukii Gilasian & Reemer sp. nov. (male holotype). 1. Adult, lateral view; 2. Mesonotum, lateral view; 3. Head, lateral view; 4. Head, frontal view. Scale bar = 0.5 mm.

FIGURES 5 – 7. Myolepta pazukii Gilasian & Reemer sp. nov. (male holotype). 5. Abdomen, dorsal view. Scale bar = 0.5 mm; 6. Hypandrium, lateral view; 7. Hypandrium, ventral view. Scale bar = 0.1 mm.

Tables

TABLE 1. Morphological differences between males of M. pazukii sp. nov. and M. nigritarsis.

Morphological characters	M. pazukii	M. nigritarsis
lateral orange spots on abdominal tergite 3	triangular, never reaching the posterior margin of the tergite	rectangular, reaching the posterior margin of the tergite
colouration of posterior margin of abdominal tergites 3 and 4	orange	black
leg colouration	tibiae orange in basal third and at apex, tarsi orange except tarsomeres 4–5	tibiae and tarsi entirely black
stripe of pale pruinosity along eye margin at level of antennae	distinctly wider than height of scape	clearly narrower than height of scape
eye contiguity, length	about half as long as ocellar triangle	about as long as ocellar triangle