Aegypoecus bengalensis Dik, 2019

Shrestha, Pratichhya & Dik, Bilal, 2019, Chewing lice from the white-rumped vulture in Nepal, with description of a new species of Aegypoecus, Zootaxa 4691 (5), pp. 491-500 : 493-497

Aegypoecus bengalensis Dik , new species

( Figs 2–16 )

Type host: Gyps bengalensis (Gmelin, 1788) , white-rumped vulture.

Type locality: Pithauli , Nawalparasi District, Nepal.

Type material: Holotype ♂ (BD-NPL-001) ex Gyps bengalensis, Pithauli, Nawalparasi District, Nepal, Pratichhya Shrestha coll., February 2017 . Paratypes: 2♀ (BD-NPL-002, BD-NPL-003) and 1 nymph (BD-NPL-004), with same data as the holotype .

Etymology: The specific epithet is taken from the species name of the type host.

Description. Male: Habitus as in Figs 2 , 11 . Head ( Fig. 4 ): Large, pentagonal, wider than long. Marginal carina interrupted by a hyaline margin in median, also interrupted in laterally into two parts as pre- and post-marginal carina. Pre-marginal carina narrower and shorter than post-marginal carina. Dorsal pre-antennal suture extends to lateral marginal interruption. Dorsal anterior plate large, pentagonal, concave in anterior and tapered to posterior. Ventral anterior plate present, reduced. Mandibles are stout and well pigmented, large at the base; pointed in the tips. Sitophore sclerite well developed, larger than lingual sclerite. Coni small. Eyes present. Post-antennal region is rounded temporally. Temporal marginal carina narrowed. Ocular and marginal temporal setae long. Four long temporal setae, one dorsal, two marginal and one ventral, and one very short fifth seta, difficult to see it. Gular plate large, protruded laterally, tapered anteriorly.

Thorax ( Figs 2 , 5 , 13 ): Shorter and narrower than head. Prothorax concave anteriorly, convex posteriorly. Pronotum almost entirely divided medially with a narrow slit, and rounded laterally. One moderately long dorsolateral marginal seta on each side of prothorax. Prothoracic sternal plate pyriform, deeply notched posteriorly. Pteronotum slightly larger than pronotum, concave anteriorly, deeply notched antero-medially, with rounded lateral margins, and convex posteriorly. Five setae on each lateral side of pterothorax: one short spine-like and four long, with three of the long setae in the cluster. The pterothorax also has two long posterolateral marginal setae, and 9–10 lanceolate postero-marginal setae on each side.

Abdomen oval, with many irregular tergal and sternal lanceolate or spindle-like setae ( Figs 2 , 14 ). Paratergal plates large and heavily sclerotized. Spiracles are distinct in segments III-VIII. Visible segment VIII is reduced, fused to latter segment, and interpreted as segment IX-X. The last segment narrowed, seen as a strip on dorsal view. Tergites medially divided, sternites are absent. Postspiracular setae present on segments III-VIII, longer than remaining setae. Rows of tergal, sternal and pleural setae irregular, and difficult to accurately count in some segments because they overlap ( Table 1 ).

Male genitalia as in Figs 6 , 14 . Basal plate long, reaching to posterior border of visible segment IV, heavily sclerotized and concave on distal end. Parameres slightly tapered and curved inward. Endomeres short, oval with a proximal extension. Aedeagus slender and short, reaching inner margins of parameres.

Measurements (1): HL 0.67 mm; HW 0.92 mm; HI 0.73; PrAL 0.23 mm; PrAW 0.61 mm; PoAL 0.38 mm; TL 0.35 mm PrW: 0.56 mm; PtW 0.71 mm; AL 1.06 mm; AW 1.19 mm; ToL 2.04 mm.

Female: Habitus as in Figs 3 , 12 . Similar to male but larger. Head with five long temporal setae and one minute spine-like seta. Dorsal anterior plate as in Fig. 7 . Thorax: Pterothoracic sternal plate as in Figs 8 , 15 . Abdomen: Chaetotaxy of ventral terminal segments and subgenital plates as in Fig. 10 . Dorsal terminal segments and chaetotaxy as in Figs 9 , 16 .

Measurements (2): HL 0.67–0.72 mm; HW 0.92–1.06 mm; HI 0.68–0.73; PrAL 0.26–0.29 mm; PrAW 0.68– 0.81 mm; PoAL 0.39–0.46 mm; TL 0.38–0.45 mm; PrW 0.61–067 mm; PtW 0.78–0.85 mm; AL 1.31–1.44 mm; AW 1.26–1.40 mm; ToL 2.35–2.53 mm.

Remarks. Price et al (2003: 141) listed seven valid species of Aegypoecus : A. brevicollis (Burmeister, 1838) ; A. trigonoceps (Giebel, 1874) ; A. perspicuus ( Kellogg, 1914) ; A. hopkinsi Dhanda, 1960 ; A. clayae Dhanda 1961 ; A. jordani Dhanda, 1961 ; and A. africanus Dhanda, 1961 . An additional species, Aegypoecus guralpi Dik, Muz & Üstüner, 2015 , proved to be a junior synonym of Neophilopterus incompletus ( Denny, 1842) ( Dik 2016) .

Aegypoecus bengalensis is morphologically closest to A. africanus , particularly in the dorsal and ventral anterior head plates, and the male genitalia. However, the prothorax, pterothorax and pterothoracic sternal plate, as well as the abdominal chaetotaxy are different from those of A. africanus . The pronotum of A. bengalensis is divided into two parts ( Fig. 5 ), but undivided in A. africanus ( Dhanda 1961: fig. 13), and the dorsolateral marginal setae on each side of prothorax are shorter in A. bengalensis . The pteronotum of A. africanus has a wide and deep median anterior notch ( Dhanda 1961: fig. 13), while that of A. bengalensis is narrow and less deep ( Fig. 5 ). Also, the pterothoracic sternal plates are different in both species, with that of A. africanus being roughly trapezoidal with distal indentations ( Dhanda 1961: fig. 18), while that of A. bengalensis is pear-shaped ( Fig. 8 ).

Dhanda (1961) stated that the species of Aegypoecus had four long marginal temporal setae and, if a fifth seta was present, it was short and spine-like. The male of A. bengalensis fits that description, but the females have five long temporal setae on both sides and one minute spine-like seta on the left side only.

Figures

FIGURES 2–3. Aegypoecus bengalensis, habitus: 2, dorsal and ventral views of male. 3, dorsal and ventral views of female.

FIGURES 4–6. Aegypoecus bengalensis, male: 4, dorsal and ventral views of head. 5, dorsal view of thorax. 6, genitalia.

FIGURES 7–10. Aegypoecus bengalensis, female: 7, dorsal anterior plate. 8, pterothoracic sternal plate. 9, dorsal view of terminal segments. 10, ventral view of terminal segments.

FIGURES 11–12. Aegypoecus bengalensis, habitus: 11, ventral view of male. 12, dorsal view of female.

FIGURES 13–14. Aegypoecus bengalensis, male: 13, dorsal view of thorax. 14, ventral view of terminal segments and genitalia.

FIGURES 15–16. Aegypoecus bengalensis, female: 15, pterothoracic sternal plate. 16, dorsal view of terminal segments.