Corethrella (Corethrella) buettikeri Cranston, 1980

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 58-59

Corethrella (Corethrella) buettikeri Cranston

Corethrella buettikeri Cranston 1980:286 . Type locality: Adnan , in Wadi Iwrakh at w. fringe of Harrat al Buqum, 20°26'N 41°31'E, 160 km SE Taif, Saudi Arabia. Holotype ♂ (BMNH).

DIAGNOSIS: Male and female adults: only extant species of Corethrella in the Old World with a plain wing (Figs. 61G, 66K) and thorax nearly completely yellowish light brown ( Fig. 39D).

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view likely nearly circular (partially crushed by coverslip) (as in Fig. 6F). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16B). Antenna uniformly light brown; pedicel without distinctive, more elongate, stout, dorsal or dorsolateral setae; flagellomeres as in Fig. 19H (flagellomeres 11–13 missing), sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus light brown; segment 3 swollen apically. Thorax (as in Fig. 39D): Yellowish light brown with slightly darker pigmentation on medial area of scutum, mediotergite. Posterior portion of dorsocentral row with 2 elongate setae situated somewhat lateral to one another. Prescutal suture uncertain. Anterior anepisternum divided diagonally by sinuous suture, dorsal portion about equal to ventral portion. Ventral portion of posterior anepisternum pale, shape uncertain. Wing (Fig. 61G): Apex of R 2 basal to apex of M 1. Plain, without pattern of pigmented veins and/or scales; veins (other than wing margin) with only setae. Halter equal in pigmentation to scutellum. Legs (as in Fig. 39D): Forelegs missing. Others light brown, basal 0.6 of midfemur and hind femur more lightly pigmented. With only slender setae, lacking scales (except for patch of elongate scales on posterior portion of hind tibia). Midleg with thick, subapical setae on each of at least tarsomeres 1–3. Apices of midleg fifth tarsomere undivided, with claws slightly subapical to apical (as in Fig. 75D). Claws of midleg longer than those of hind leg. Each claw without inner tooth. Anterior claws of each leg without a basal prong. Midleg claws unequal. Empodia thick. Abdomen (Fig. 76G): Yellowish, with posterior margin of tergite 7, all of segment 8–9 more darkly pigmented. Genitalia (Fig. 84C): Gonocoxite uniformly light brown, moderately tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with setae of similar thickness as some other setae on gonocoxite, equal in size to each other except for posteriormost seta slightly thicker, with row curving posteromedially with posteriormost seta of row positioned dorsomedially. With one dorsomedial stout seta, tapering from base. Gonostylus (in retracted position) straight, curved subapically, somewhat more slender subapically; one elongate, thick subbasal seta, situated ventrally; with thick, blunt apical peg. Aedeagus slender, elongate, tapering from base but with abrupt narrowing subapically, pointed apically, with lateral margins separate apically.

Female adult. Descriptive statistics: see Tables 6–11. As for male, with following differences. Head: Coronal suture elongate, extending ventrally past ommatida (as in Fig. 16B). Antennal flagellomeres as in Fig. 26E, sensilla coeloconica distributed as in Table 1. Clypeus elongate, not clearly visible. Mandible with small, pointed teeth. Palpus as in Fig. 33K. Wing (Fig. 66K). Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Uniformly yellowish light brown.

Immatures. Unknown.

DISTRIBUTION AND BIONOMICS: Corethrella buettikeri is known only from the type locality in Saudi Arabia (Fig. 114). Cranston (1980) noted that the type locality was more precisely located in Wadi Iwrakh at the western fringe of Harrat al Buqum, 20°26'N 41°31'E, 160 km SE Taif at 1,250 m. The abdomens of the two female paratypes were filled with blood ( Cranston 1980), so it is certain that females of this species feed. There are three frog species living at this Wadi, Bufo arabicus Heyden , Hyla savignyi Audouin and Euphlyctis ehrenbergii (Peters) ( Balletto et al. 1985) and one or more of them are the likely host of female C. buettkiker :

Of the original type series, at least the two females were collected with a sticky trap. It is uncertain how the two males were obtained.

TAXONOMIC DISCUSSION: Males and females were collected at the same locality and date and shared a distinctive pigmentation pattern. The type specimens were all slide-mounted in Berlese fluid and ringed with Euparol and the Berlese fluid is beginning to discolor. In addition, the specimens are partially crushed and broken up under the coverslips, making remounting in Canada Balsam nearly impossible without losing parts. The paratype male examined here had only two wings, one hind leg and the abdomen present.

Cranston (1980) described the adults of this species in detail and provide illustrations of the wing, some female mouthparts, claws, and both male and female genitalia. He showed the aedeagus as apically rounded but in fact it is pointed.

The specimens in the type series have labels that name the species C. buttikeri , but this is clearly a misspelling.

MATERIAL EXAMINED: Holotype, adult male on microscope slide, labeled “ SAUDI ARABIA: Adnan , 22-IX-1978, W. Büttiker ” ( BMNH). 1 ♂, 2 ♀ paratypes labeled as for holotype ( BMNH).

DERIVATION OF SPECIFIC EPITHET: The name buettikeri was proposed in recognition of the collector W. Büttiker.