Corethrella (Corethrella) incompta Borkent, 2008

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 : 80-81

Corethrella (Corethrella) incompta Borkent, 2008

Fig. 39 ; Appendix 1

Material examined

BRAZIL – Bahia State • 1 ♀, adult; Porto Seguro, RPPN Veracel , muçununga; 16°21ʹ33ʺ S, 39°08ʹ15ʺ W; 72 m a.s.l.; 30 Aug. 2019; A.P. Amaral leg.; frog-call trap; CE-MHS .

Description

Female adult (n = 1)

HEAD. Sensilla ( Fig. 39A ): Ocular row with 1 thick offset seta at ventral part, 19 setae extending posteriorly. Subocular row not well-defined; vertex and interocular space with many slender setae. Postgenal row with 13 slender setae ranging from posterior end of ocular row to ventromedially. With 2 thick ventromedial setae (see discussion below).

THORAX. Sensilla ( Fig. 39B ): Antepronotum with 3 thick and 6 slender setae on ventrolateral margin. Postpronotum with 1 thick dorsal seta and 4 slender, more ventral ones. Scutum, prescutal area with 3 thick setae vertically arranged near prescutal suture, 1 thick seta more anteriorly; about 6 thick/ intermediate setae anteriorly, reaching anterior portion of dorsocentral row; 6 slender setae scattered on ventral portion. Antealar area with 8 thick/intermediate setae loosely aligned dorsoventrally on anterior portion and 8 thick/intermediate setae more posteriorly, forming a U-shape; additionally, a group of 18 slender setae on dorsal portion. Supraalar area with 6 thick setae anteroposteriorly aligned, 11 slender setae surrounding. Dorsocentral row, posterior part with group of 5 thick offset setae; about 34 thick/ intermediate and 25 slender completing row. Scutellum with 10 thick setae. Posterior anepisternum bare. Anepimeron with 10 slender setae.

WING. R 3 /R 1: 0.55; R 2+3 /R 2: 0.55.

LEGS. Empodium ( Fig. 39C ) elongate and thick, with 12 branches. Ta1/Ta2: 3.07; Ta3/Ta4: 1.11.

Distribution and biology

Corethrella incompta is newly recorded both from the state of Bahia and from the Brazilian Northeast region.A single individual was collected via frog-call pan trap at an area of white-sandy tropical savanna patch inside a fragment of lowland Atlantic forest (mussununga ecosystem), at RPPN Estação Veracel.

It is otherwise known from Mexico, Cayman Islands, Costa Rica, Ecuador, French Guiana, and Brazil (state of Pará, Amazonian region), at altitudes ranging from 0 to 269 m a.s.l. ( Borkent 2008).

Remarks

The studied female individual matched the original description of Corethrella incompta fairly well, but seems to differ in relation to the empodia. Borkent (2008) did not describes the empodium in detail, defining it only as slender. There is, however, a general correspondence between what he considered to be slender, of intermediate thickness or thick with the classification here used. The large and highly branched empodium of the specimen examined is in accordance with other species in the wirthi group. Since this is the only major difference found from the original description, the individual is conidered as Corethrella incompta and the empodium redescribed.

The number of ventromedial setae on the head is difficult to interpret. The postgenal row appears to be continuous with the ventromedial setae, making it difficult to discriminate one from the other.

Figures

Fig. 39. Corethrella incompta Borkent, 2008, 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.