Idricerus decrepitus ( Walker, 1860 )

Hassan, Muhammad Asghar & Liu, Xingyue, 2021, Taxonomic notes on owlflies from Pakistan (Neuroptera: Myrmeleontidae Ascalaphinae), Zootaxa 4970 (3), pp. 401-452 : 441-442

Idricerus decrepitus ( Walker, 1860)

Ascalaphus decrepitus Walker, 1860: 197 . Type locality: India.

Diagnosis. Idricerus decrepitus is characterized by having distinctive specklings along the crossveins in the fore- and hind wings a light brown pterostigma, and two crossveins in forewing and four crossveins in hind wing. Moreover, it can be easily distinguished by the yellow legs with broadly dark brown femora, and the dorsomedian black band on tibia.

Measurement (♂ n=1). Forewing length: 35.0 mm, width 8.0 mm; hind wing length: 30.2 mm, width 7.3 mm; abdominal length: 18.2 mm; body length: 27.0 mm.

Re-description. Male ( Fig. 22 ). Head ( Figs 23A, F ). Postorbital sclerite brownish yellow. Occiput reddish brown. Vertex dark brown, with white setae. Frons brownish yellow, proximally dark brown, with white setae. Anterior orbital sclerite indistinct, proximal 1/3 of paraocular band brownish yellow, distally dark brown, proximal 1/3 with white setae, except with some mixed black setae. Clypeus brownish yellow, with greyish setae. Labrum brownish yellow, with stiff brown setae. Mandibles greyish yellow, reddish brown at tip, covered with greyish setae at proximal 1/3. Maxillary and labial palpi yellow, with short black setae. Posterior genal triangle greyish yellow, with white setae, mixed with some black setae. Eyes without transverse furrow. Antennal toruli brownish yellow. Antennae shorter than distance between base of forewing to pterostigma, yellow, with alternating yellow and black bands, intensity of black band reduce consecutively after each band; scape and pedicel brownish yellow, with greyish yellow setae or mixed dark and greyish yellow. Club pyriform, brownish yellow, with verticils ( Fig. 23E ).

Thorax ( Fig. 23A ). Dorsal cervical plates dark brown, with greyish yellow setae; cervical sclerite greyish yellow, without setae. Pronotum narrow, brownish medially, margins brownish yellow; anterior- and posterior margins flexed upward, with greyish yellow setae, mixed with some dark brown setae; lateral margins rounded, dark brown, brownish yellow at posteriorly, with long brownish setae. Mesonotum ochre brown; prescutum with dark brown setae, anterolateral margins yellow with long greyish yellow setae; anterolateral margins of mesoscutum brownish yellow, with brownish setae, lateral margins with greyish yellow setae; mesoscutellum with a transverse grove subdistally, posteromedially yellow rhombus-shaped, with brownish setae, proximal 2/3 short, long at distal margin. Metanotum ochre brown; postnotum ochre brown, medially and posteriorly brownish yellow, with mixed greyish yellow and brown setae. Pleuron ochre brown, with greyish yellow setae ( Fig. 23B ).

Legs yellow ( Fig. 23B ). Foreleg. Coxae dark brown, with long greyish yellow setae. Trochanter brownish yellow, with mixed short dark and greyish yellow setae. Femur dark brown, base and apex yellow, with mixed short and long black setae, the anterolateral margin covered with long greyish yellow setae. Tibia yellow, slightly darker at apex, a distinct median dark streak, with mixed black and greyish yellow setae. Tibial spurs dark brown, equal to combined length of Ta1–Ta3. Tarsomeres brownish yellow, dark at apex, covered with short black setae; Ta1–Ta4 subequal in length; Ta5 subequal to combined length of Ta1–Ta4. Mid leg. Concolorous to foreleg. Hind leg. Concolorous to mid leg, except tibial spurs equal to length of Ta1–Ta2.

Wings ( Fig. 22 ). Membrane transparent. Veins alternating dark brown and brownish yellow, mottled, with sparse short black setae. Pterostigma indistinct, with two crossveins in forewing ( Fig. 23C ), four in hind wing ( Fig. 23D ), crossveins heavily brownish shaded, apical area beyond Sc+R with two rows of cells. Forewing longer than hind wing. Anal angle distinctly produced. Presectoral area with seven crossveins, with the distal one biaereolated. Rs with six major forks. Hind wing. Presectoral area with five crossveins, with the distal one biaereolated. Rs with six major forks.

Abdomen shorter than hind wing ( Fig. 22 ). Tergum dark brown, brownish yellow at hind margins, with brownish yellow setae. Tergum. T1 split dorsally, posterolateral margins slightly greyish yellow, with mixed dark brown and greyish yellow setae. Acrotergite dark brown. T2 short, medially with a pair of obtuse yellow markings, covered with greyish yellow setae, but a few short black setae in the middle. T3 with a pair of distinct yellow markings at posteromedian margin, with short black setae, medially dense long greyish yellow setae. T4-T8 with relatively indistinct yellow markings on the posterior margins, covered with short black setae black, but a few greyish yellow setae on the proximal margins. Sternum greyish, with greyish yellow setae.

Male genitalia ( Figs 24A–E ). Brownish yellow. Tergum 9 (T9) subquadrate, with short black setae; sternum 9 (S9) quadrate, with triangular apex, with mixed short and long black setae; ectoprocts (epr) subquadrate, covered with mixed short and long black setae; gonarcus (gs) medially notched, slightly wider at lateral margins; parameres (pa) saw-shaped in ventral margin with fine dentation on inner margin; pulvini (pv) yellow, with several long yellow gonosetae.

Material examined. PAKISTAN. Azad Kashmir Territory : 1♂, District Poonch , Rawalakot Valley , The University of Poonch, [33°50’58.776”N, 73°46’26.5434”E], 1645 m, 1.viii.2019, leg. M.A. Hassan ( CAU) .

Distribution. Pakistan; China (Tibet), India (Arunachal Pradesh, Assam, Jammu & Kashmir, Meghalaya, Uttar Pradesh), Nepal (Bagmati, Gandaki), Turkmenistan ( McLachlan 1873a; Ghosh & Sen 1977; Ghosh 1988; Sziráki 2000; Zhang et al. 2015; Oswald 2020).

Figures

FIGURE 22. Idricerus decrepitus (Walker). A. Male, habitus. Scale bar: 5.0 mm.

FIGURE 23. Idricerus decrepitus (Walker). Male.A. Head and thorax, dorsal view; B. Lateral view. C–D. Pterostigma of right fore- and hind wing; E. Antenna. F. Head, anterior view. Scale bars: 5.0 mm (B); 2.0 mm (A); 1.0 mm (F).

FIGURE 24. Idricerus decrepitus (Walker). A. Male genitalia, lateral view; B. Same, ventral view; C–E. Gonarcus, parameres and pulvinus: C. Dorsal view; D. Same, ventral view; E. Same, lateral view. Scale bar: 0.5 mm.