Corethrella (Corethrella) appendiculata Grabham, 1906

Amaral, André P., Mariano, Rodolfo & Pinho, Luiz Carlos, 2023, Description of five new species of frog-biting midges (Diptera, Corethrellidae) from Brazil and examination of new morphological characters with utility for taxonomic and phylogenetic studies, European Journal of Taxonomy 874 (1), pp. 1-120 : 69-70

Corethrella (Corethrella) appendiculata Grabham, 1906

Fig. 32 ; Appendix 1

Material examined

BRAZIL – Santa Catarina State • 1 ♂, 1 ♀, adults; Indaial, Morro Geisler ; 26°54ʹ00ʺ S, 49°13ʹ00ʺ W; 100–280 m a.s.l.; 27 Jan. 2016; C.B. Marcondes leg.; CDC trap; CE-MHS .

Description

Male and female adults (1 ♂, 1 ♀)

HEAD. Sensilla ( Fig. 32A ): Ocular row with 1 thick, slightly offset seta at ventral portion, 1 more dorsal, and row of 16 setae shortly extending posteriorly. Subocular row not well-defined. Vertex with several setae. Postgenal row with 16–19 slender setae ranging from posterior end of ocular row to ventromedially. With 2 ventromedial thick setae.

THORAX. Sensilla ( Fig. 32B ): Antepronotum with 2 intermediate ventrolateral and 10–13 intermediate lateral setae. Postpronotum with 1 thick dorsal and 2–4 intermediate more posteriorly, with 4–13 slender setae in between. Scutum, prescutal area with 2 thick and 1 intermediate vertically aligned setae near prescutal suture; 4–7 intermediate and 10–14 slender setae anteriorly. Antealar area with 5–7 thick, 10–12 intermediate, and 10–12 slender setae centrally located; 18–40 slender setae more dorsally, near dorsocentral row. Supraalar area with 2–3 thick ventral setae, with 3–8 intermediate and 27–34 slender setae surrounding. Dorsocentral row, posterior region with 6–7 thick and 5–7 slender offset setae; 18– 25 thick/intermediate and about 60 slender setae filling row. Scutellum with 14 thick setae. Posterior anepisternum without setae (see discussion below). Anepimeron with 22–23 slender setae.

WING. Male R 3 /R 1: 0.40; R 2+3 /R 2: 0.85. Female R 3 /R 1: 0.52; R 2+3 /R 2: 0.68.

LEGS. Empodium ( Fig. 32C ) of intermediate length and thickness, with 3 branches. Male Ta1/Ta2: 3.25; Ta3/Ta4: 0.67. Female Ta1/Ta2: 2.94; Ta3/Ta4: 1.00.

Distribution and biology

The specimens studied have previously been recorded by Amaral et al. (2019). They were collected with CDC traps in a fragment of Atlantic forest in Indaial, northern Santa Catarina State. The precise altitude was not reported by the collector, but altitudes in the sampled area range from 100 to 280 m a.s.l.

This species has otherwise been recorded from the southern United States, Mexico, Central America and the Caribbean, Venezuela, French Guiana, northern Argentina, and the Brazilian states of AM, BA, GO, and SP, at altitudes ranging from 0 to 1700 m a.s.l. ( Borkent 2008).

Remarks

Adults of Corethrella appendiculata have an unusually large number of slender supraalar setae, not observed in any other species. Borkent (2008) recorded the presence of posterior anepisternal setae in some specimens of C. appendiculata , but that was not observed in the individuals examined here. This species has a large intraspecific variation and a widespread distribution and, for these reasons, Borkent (2008) conjectured the possibility that the name included more than one species; thus, the presence of cryptic species in Brazil is possible.

Figures

Fig. 32. Corethrella appendiculata Grabham, 1906, adult. A. Cranial setae, anterior and posterior views, and female clypeus in anterior view. B. Thoracic setae, lateral view. C. Hind leg claw and empodium, lateral view.