Anastoechus spinifacies Bezzi, 1924

Greathead, David J. & Evenhuis, Neal L., 2004, New species of Bombylioidea in Mario Bezzi’s Unpublished Hungarian Museum Manuscript, Zootaxa 773, pp. 1-56 : 17-19

Anastoechus spinifacies Bezzi, 1924

( Figs. 4 , 8)

19. Anastoechus spinifacies 1Ψ Eritrea: Assab, vii.1907 (Katona). MS page 10.

Bezzi, 1920: 100 – listed [1ɗ]: Somalia: Matagoi a Lugh, xi.1895 (V. Bottego) in MCSN. Bezzi, 1924: 73 – in key validating the name A. spinifacies ; p. 75 mentioned a specimen from

Assab.

Evenhuis & Greathead, 1999: 90 – indicated an undetermined number of syntypes in MCSN.

Types: Assuming that Bezzi’s (1924) mention of the Assab specimen was in reference to the intended type female in the Hungarian Museum, there would then be a total of 2 syntypes in the type series. The female from Assab in HNHM is destroyed, leaving a male from Somalia in MCSN as the only surviving syntype, which is here designated lectotype ( Fig. 8).

Remarks: The characters leading to A. spinifacies in Bezzi’s (1924) key to Afrotropical Anastoechus spp. specify: distinct bristles on upper side of body; scutellum red, at least on disc; wings with marginal cell [r1] hyaline, at least in its terminal half; basal joints of antennae red or yellowish; palpi yellow; proboscis shorter than body, labium black; wings hyaline, costal cell not darkened or merely pale yellowish; yellowish­grey or whitish costal comb; face of female with a few strong bristles in middle; antennal flagellum of unusual length; bristles on frons and abdomen mainly dark or even black; abdomen entirely black; wing veins dark coloured.

The interpretation of these characters and the manuscript description is complicated by the only known syntype [here = lectotype] being a male and the intended holotype a female, besides the male is in poor condition and appears to have been stored in fluid at some time. Thus, the male does not have truly red basal joints of the antennae but rather brown ones, abdomen extensively brown at sides. The red colour could have become brown through a combination of storage in fluid and the passage of time since the specimen was dried. However, the abdomen was clearly never completely black. This could be a sexual difference as there is a degree of sexual dimorphism in the colour of the cuticle and vestiture of Anastoechus spp.

The male is substantially denuded, has the remaining hair matted, a crumpled abdomen and the legs are largely missing – only fore legs (less fifth tarsomere on one side), femora of middle legs and one hind femur with part of tibia remain.

Description: Head black but face extensively brown and projecting snout­like. Eyes separated by width of ocellar triangle and twice the width of a lateral ocellus at vertex. Occiput much inflated. Frons with stiff bristles above and at sides only in lower half, these bristles black above and paler brown below. Frons and face with dense long stiff white hair. Occiput and underside of head with decumbent white scale­like hairs. Antennae brown, hairs white, ratio 4:1:8, flagellum swollen in basal third, bulging more on underside, tapering to a narrow linear apical third. Proboscis black, slender about equal in length to head and thorax combined. Palpi short, brown with white hairs and largely concealed by facial hair.

Thorax black but calli, scutellum and immediately below wings brown. Traces of long white hair remain in front and on pleura.

Legs yellow­brown, basal halves of femora blackened. Bristles yellow, traces of a row remain beneath remaining hind femur. Remaining claws long, slender, gently curved, yellow­brown at bases black at apices. Pulvilli not apparent.

Wing membrane wrinkled appearing white tinged and more greyish in basal half. Veins yellow­brown. Costal comb white. Venation typical for genus. Squama white with a white fringe. Haltere yellow­brown, knob paler at apex.

Abdomen with dorsum black at base and along mid­line brown at sides, sterna brown. First tergum with yellowish hair, remainder totally denuded but sockets for rows of strong bristles, interrupted at mid­line are apparent.

Length: of body> 10 mm, of proboscis, 8 mm; of wing, 12 mm.

Since this male from Somalia is the only surviving syntype specimen known, the identity of the species must be determined from it rather than Bezzi’s manuscript description of the female from Assab and some doubt remain as to whether the two were indeed conspecific. The description of the female differs from the above in additional characters not visible on the male as follows: head and thorax with very many bristles, mostly yellow but blackened on posterior margins of abdominal terga; legs with white scales; base of wing pale yellow, otherwise greyish hyaline; frons at vertex somewhat wider than an eye; black hairs on ocellar tubercle otherwise hair on head yellowish or white and no strong setae; antennal flagellum black; thorax mainly with yellowish hair and bristles, greyish short hairs on dorsum; margin of squama yellowish; abdomen all black with greyish hair and blackish bristles on posterior margins of terga; sterna black with white vestiture; legs with two spines beneath mid­femora and 6–7 beneath hind.

These descriptions most nearly correspond with the male and female of A. miscens (Walker) from the Eritrean coast further to the north, near Massawa (see Greathead, 1967); but these specimens have entirely black antennae, the hair on the ocellar triangle and frons is not black in either sex and the frons of the males at the vertex is usually less than the width of the ocellar triangle, though variable. However, a male from Lodar in South Yemen does have black hair on the ocellar triangle and frons and the frons is as wide as that of the syntype male. The genitalia of the syntype ( Fig. 4 ) are very similar to those of A. miscens (see Greathead, 1967: Fig. 22) but differ chiefly in the shape of the gonostylus. This has a strong thorn­like spine at its apex ( Fig. 4 b) and is not simply pointed as in A. miscens ( Fig. 4 c). The shape of the gonostylus has also been found to be the only clear difference between the genitalia of A. exalbidus and A. nivifrons (Greathead, 1980: Fig. 1 a–c) which are otherwise readily separated by much bigger differences in the vestiture. Therefore, small as the differences are between A. miscens and A. spinifacies and their largely sympatric distributions they are separate species. The Lodar male also differs from males of A. miscens in that the hair is whiter and lacks the greenish­yellowish tinge and in that the feint brown infuscation of the middle of the wing is more extensive and reaches to near the end of cell dm and occupies the whole of cua1 rather than ending just beyond the middle of dm and cua1.

Additional material examined. S. Arabia [ Yemen]: 1ɗ, Lodar, 8 AM, 18.v.1967 (K.M. Guichard) (DJG).

Figures

FIGURE 1. Example page of Bezzi’s Hungarian Museum manuscript. First page of final copy.

FIGURE 4. Anastoechus male genitalia. A, genitalia of Anastoechus spinifacies Bezzi. B, gonostylus of A. spinifacies Bezzi. C, gonostylus of A. miscens (Walker).