Corethrella (Corethrella) quadrivittata Shannon & Del Ponte, 1928

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 : 75-76

Corethrella (Corethrella) quadrivittata Shannon & Del Ponte, 1928

Fig. 35 ; Appendix 1

Material examined

BRAZIL – Santa Catarina State • 1 ♀, adult; Bom Retiro, RPPN Grande Floresta das Araucárias , “ Lago da casa grande ” [pond by the lodge]; 27°53ʹ39ʺ S, 49°27ʹ43ʺ W; 942 m a.s.l.; 18 Nov. 2017; L.C. Pinho et al. leg.; CDC trap; CE-MHS . – Bahia State • 1 ♀, adult; Porto Seguro, RPPN Veracel , “ trilha escolar ” [educational trail]; 16°23ʹ10ʺ S, 39°10ʹ11ʺ W; 89 m a.s.l.; 28 Aug. 2019; A.P. Amaral leg.; frog-call trap; CE-MHS .

Description

Female adult (n = 2)

HEAD. Sensilla ( Fig. 35A ): Ocular row with 2 thick offset setae on ventral portion, more dorsally about 13–14 setae extending posteriorly. Subocular row weakly defined anteriorly, with about 15 slender setae on posterior part. Vertex with multiple slender setae. Postgenal row with 9–11 intermediate and about 15 slender setae, ranging from end of ocular row to ventral portion of head. With 2 thick ventromedial setae.

THORAX. Sensilla ( Fig. 35B ): Proepisternum with 25–50 slender/intermediate setae.Antepronotum with 20–28 slender setae, most on posteroventral portion. Postpronotum with 2 thick and 4–5 slender dorsal setae. Scutum, prescutal area with 3 thick posterior setae dorsoventrally aligned, 18–23 intermediate/ slender setae grouped on ventral portion. Antealar area with 7–15 thick and 24–28 intermediate/slender setae concentrated on ventral portion. Supraalar area with 4 thick setae, with about 23 intermediate/ slender setae surrounding.Dorsocentral row, posterior part with 5 thick offset setae; 30 thick/intermediate and 45 slender setae filling row. Scutellum with 12 thick setae. Posterior anepisternum bare.Anepimeron with 10–11 slender setae.

WING. R 3 /R 1: 0.52–0.54; R 2+3 /R 2: 0.56.

LEGS. Empodium ( Fig. 35C ) of intermediate length and thickness, with 4 branches. Ta1/Ta2: 2.47–2.59; Ta3/Ta4: 1.08–1.17.

Distribution and biology

The specimen from Santa Catarina has previously been recorded by Amaral et al. (2019). It was collected with a CDC trap near a pond, in an open area of Araucaria moist forest (942 m a.s.l.). The specimen from Bahia was collected with a frog-call pan trap, in an area of Atlantic rainforest (at 89 m a.s.l.). These records show the broad altitudinal and ecological range of the species, otherwise known from Mexico, Costa Rica, Suriname to Argentina and southern Brazil, in arid and humid climates, and at altitudes ranging from 0 to 1400 m a.s.l. ( Borkent 2008). This might indicate the presence of cryptic species.

Remarks

Corethrella quadrivittata and C.edwardsi are the only studied species that have setae on the proepisternum. Furthermore, C. quadrivittata has a uniquely setose antepronotum. Two specimens not included in this study, collected in Rio de Contas, Bahia, keyed out to C. quadrivittata but probably represent a different species. They had two sensilla coeloconica on each of flagellomeres XII–XIII, a bare proespisternum and three small setae on the hind coxa. These were the only specimens which had more than one tiny seta on the hind coxa. See Morphology remarks for more details.

Figures

Fig. 35. Corethrella quadrivittata Shannon & Del Ponte, 1928, female adult. A. Cranial setae, anterior and posterior views, and clypeus in anterior view. B. Thoracic setae, lateral view. C. Hind leg claw and empodium, lateral view.