Litorhina evanescens (Bezzi)

Greathead, David J. & Evenhuis, Neal L., 2004, New species of Bombylioidea in Mario Bezzi’s Unpublished Hungarian Museum Manuscript, Zootaxa 773, pp. 1-56 : 42-45

Litorhina evanescens (Bezzi)

( Figs. 29–30 )

70. Litorrhynchus evanescens ɗɗΨΨ Tanzania: Mto­ya­Kifaru, 1905 (Katona). Eritrea: Keren. “Afr. Or. Ukami”. MS page [74].

Bezzi, 1924: 213 – key only.

Evenhuis & Greathead, 1999: 414 – listed 2 syntypes in MSNM.

Types: The type series consists of an undetermined number of males and females from “Mtoya­Kifaru” in Tanzania. Two syntypes: 2Ψ, Tanzania, Mto­ya­Kifaru, 1905 (Katona) have been confirmed in MSNM. The two specimens are generally in good condition but one of these lacks one antennal flagellum, one hind leg and the tarsus of the other. The second female lacks one hind leg only and is here designated lectotype ( Fig. 29 ).

Remarks: This species had not been recognised in collections from the characters in

Bezzi’s (1924) key and was simply listed by Bowden (1980) as ‘no locality’. However,

once the specimens in MSNM were seen it was apparent that it is a relatively common, but

somewhat variable, eastern African species. In particular, the evanescent part of the wing

pattern may be fully darkened and so that the statement Bezzi’s (1924) key ‘middle band

usually not extending to hind border of wings’ is misleading even with reference to his

type material.

Description. Lectotype female. Head orange brown, only ocellar triangle and a small area just behind the vertex blackened. Frons with short black hair and face with short gold hairs. Occiput with narrow shining whitish scales. Face rounded, projecting little more than the length of the scape. Frons three times width of ocellar triangle at vertex, gradually broadening to level of antennae. Antennae ratio 3:1:4:3, first flagellomere conical and second narrow linear, small hairs on scape and pedicel black. Proboscis relatively short, black. Palpi orange with fine black hairs.

Thorax with Scutum black and remainder dark red­brown but centres of anepisternum and anepimeron blackened. Hair at front of scutum (collar), and upper part of pleura redbrown with a few black ones intermixed on propleura and anepisternum, katepisternum with red­brown scaly hairs, remainder of pleura bare. Scales on dorsal surface reddish in middle and paler pinkish­white along notopleural line and around posterior margin of scutellum. Bristles long, black. Plumula white.

Legs red­brown but apices of tarsi blackened. Bristles and scaly hairs on femora black, scales on tibiae gleaming silvery. Fore legs greatly shortened with tibia only three quarters length of femur and tarsus only three quarters length of tibia. Claws small, black, almost straight.

Wing ( Fig. 30 ). Costal hook black, comb black with yellow­brown scales. With a typical Litorhina wing infuscation: costal cell, r1 and r2+3, except their apices and apical half br light brown, base to MA medium brown and remainder of infuscation dark brown, also a clear prediscal fleck. Basal infuscation reaches to apical quarter anal lobe and its margin runs obliquely to posterior end of m­cu across base of dm to just before r­m crossvein. Middle infuscation occupies apical half of dm, basal half of m1, fore margin of m2 becomes evanescent before the wing margin in m2 and then runs forward across r5 to the base of the interradial vein in cell r1. Crossvein r­m just beyond basal quarter of dm, cell r5 very narrowly open at margin, m­m and m­cu both sinuous and parallel with hind margin of wing, subequal in length, M2 sinuous almost parallel to M1 and sloping towards apex of wing so that m1 is slightly wider than m2 at the wing margin. Squama brown with red fringe. Haltere black with apex of knob red­brown.

Abdomen broad, ovate. Black with hind margin of first tergum, greater parts of terga two and three except near the midline, sides of terga four and five and hind margins of terga four to six red­brown. Hair on first tergum and basal third of sides of tergum two creamy white otherwise hair at sides of terga and across apex of abdomen black and with small adpressed scattered black hairs on terga towards sides. Small scales on terga yellowbrown, also larger dense white ones forming spots at sides of third tergum and an indistinct line across the middle joining the tow spots, terga six and seven covered in white scales. Sterna red­brown with whitish hairs and scales. Acanthophorite spines red­brown.

Lengths: body 15 mm; proboscis 2 mm; wing 17 mm.

Strangely, female specimens predominate in the other material examined. These show a degree of variability. The cuticle of the specimen from Kibwezi is more extensively blackened. Those from around Dodoma in Tanzania have a more extensively red abdomen with the black confined to a row of median spots, also the evanescent part of the wing infuscation is fully darkened and reaches the wing margin although noticeably distinct. The size range is from 9–20 mm in length, but usually about 17 mm. The two males are very similar to the corresponding females but have denser more conspicuous white scales on the abdomen.

Two female specimens from Arabia also represent this species but differ from the African specimens in having black scales not yellow­brown scales on the abdominal terga and more white scales joining the two spots on tergum two forming a distinct band across the segment.

Additional material examined (all in DJG): KENYA: 3ΨΨ, Makindu, 9.v.1963 (D.J.

Greathead; 1Ψ, Kibwezi (lava), 9.vi.1981 (R.H. Markham). TANZANIA: 1ɗ1Ψ, 50 miles N of Dodoma, 7.v.1966 (D. & A. Greathead); 1Ψ, same except 70 miles N of Dodoma, 2.v.1966; 1Ψ, 80 miles N of Dodoma, 8.v.1966 (A.H. Greathead); 1Ψ. Dodoma District, hills S of Meia Meia, 15.v.1968 (D.J. Greathead). UGANDA: 1ɗ1Ψ, Karamoja, S side of Mt. Moroto, 7.x.1962 (D. & A. Greathead); 1Ψ, same except, 7.x.1962; 1Ψ, same except, 10.x.1962; 1Ψ (headless), Rukwa Rift, Kafukola, 20.v.1955 (R.F. Chapman). OMAN: 1Ψ, Dhofar, W Saka, 27.ix.1977 (K.M. Guichard). SAUDI ARABIA: 1Ψ, Adwan near Al Mindak, 27.v.1983 (A.R. Pittaway).

Figures

FIGURES 29 – 32. Lectotype specimens of species of Bombyliidae referred to in Bezzi’s manuscript. 29 – 30, Litorrhynchus evanescens Bezzi [= Litorhina] (lectotype in MSNM). 29, female habitus. 30, wing. 31 – 32, Plesiocera biumbonata Bezzi [= Epacmoides] (lectotype in MSNM). 31, male habitus. 32, head.