Corethrella (Corethrella) peruviana Lane, 1939

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 : 37-40

Corethrella (Corethrella) peruviana Lane, 1939

Figs 1 , 16 ; Appendix 1

Diagnosis

Larva

Only extant species with the following combination of characters: darkly pigmented tergal plates ( Fig. 16D ); a small, darkly colored mandibular lobe ( Fig. 16D ); head dark brown with a pale postmentum ( Fig. 16D ); ventral margin of antennal groove with about ten large denticles ( Fig. 16E ).

Pupa

Only extant species with the following combination of characters: a flattened, wide, trilobed respiratory organ ( Fig. 16G ); abdominal segments strongly expanded laterally ( Fig. 16H ); segment III with two well-developed, darkly pigmented lateral setae ( Fig. 16H ).

Material examined

BRAZIL – Bahia State • 1 ♀, adult; Porto Seguro, RPPN Veracel, mussununga ; 16°21ʹ33ʺ S, 39°08ʹ15ʺ W; 72 m a.s.l.; 30 Aug. 2019; A.P. Amaral leg.; feeding on frog ( B. faber ); CE-MHS • 1 ♀, adult; same collection data as for preceding, except frog-call trap; CE-MHS • 1 ♀, adult, with larval and pupal exuviae; same collection data as for preceding, except hand net, ground pools; CE-MHS • 1 ♀, adult; same collection data as for first, except 12 Mar. 2020; frog-call trap (chorus); CE-MHS • 1 ♀, adult; Porto Seguro, RPPN Veracel , “Rio trilha escolar” [river by educational trail]; 16°23ʹ09ʺ S, 39°10ʹ14ʺ W; 89 m a.s.l.; 13 Mar. 2020; A.P.Amaral leg.; frog call; CE-MHS • 1 ♀, adult; same collection data as for preceding, except light sheet; CE-MHS • 1 ♂, adult; same locality as for preceding; 12 Feb. 2019; M.M.L. Sousa leg.; light pan; CE-MHS • 1 ♀, adult; Igrapiúna, Estação Michelin ; 13°48ʹ14ʺ S, 39°10ʹ16ʺ W; 59 m a.s.l.; 23 Mar. 2019; A.P. Amaral leg.; CDC trap; CE-MHS . – Santa Catarina State • 1 ♂, adult; Porto Belo, Ponta do Araçá , “Brejo de altitude” [altitude marsh]; 27°07ʹ38ʺ S, 48°31ʹ20ʺ W; 115 m a.s.l.; 25 Jul. 2011; Ganzer and Fabris leg.; light trap; CE-MHS .

Description

Male and female adults (2 ♂♂, 7 ♀♀)

HEAD. Sensilla ( Fig. 16A ): Ocular row with 2 thick offset setae at ventral part, 9–12 setae more dorsally, shortly extending posteriorly. With well-defined subocular row of 9–14 slender setae. Postgenal row with 12–18 small setae, restricted to mid-posterior region. With 1 ventromedial thick seta.

THORAX. Sensilla ( Fig. 16B ): Antepronotum with 0–3 slender anteromedial setae. Postpronotum with 1 thick dorsal and 1–4 intermediate setae. Scutum, prescutal area with 4 anteroventral and 3 posterodorsal thick setae; 2–7 slender setae scattered in between. Antealar area with cluster of about 8–12 thick and 4–13 slender/intermediate setae on posteroventral portion. Supraalar area with 2–3 thick and 4–11 slender setae on ventral portion. Dorsocentral row, posterior part with 6–9 thick offset, longitudinally aligned setae; about 18–29 thick/intermediate and 10–22 slender setae filling row. Scutellum with 8–10 thick setae. Posterior anepisternum with 0–2 dorsal setae. Anepimeron bare.

WING. Male R 3 /R 1: 0.59–0.61; R 2+3 /R 2: 0.46–0.58. Female R 3 /R 1: 0.67 (0.62–0.73); R 2+3 /R 2: 0.44 (0.36– 0.61).

LEGS. Empodium ( Fig. 16C ) elongate, of intermediate thickness, with 5 (bifid, trifid or multifid) branches. Male Ta1/Ta2: 2.33–2.61; Ta3/Ta4: 1.33–1.38. Female Ta1/Ta2: 2.46 (2.35–2.60); Ta3/Ta4: 1.31 (1.27–1.40).

Larva (n = 1)

EXUVIA ( Fig. 16D ). Head, siphon, and segment X dark brown; postmentum pale; darkly pigmented tergal plates on I–VII.

HEAD ( Fig. 16E ). Roughly triangular shape in dorsoventral view, 1.16 times as wide as long. Antenna 0.53 times length of head; antennal groove 1.58 times length of antenna; ventral margin of antennal groove with about 10 large denticles. Postmentum with base moderately wide, strongly tapering, 1.39 times as wide as long; length 0.41 of head. Prementum slightly curved, with 14 blunt teeth, darkly pigmented, central one largest, remaining gently decreasing in size. Anteroventral projection of gena somewhat projected anteriorly, flattened, surface smooth. Postcoila short, not extending to lateral margin of gena. Subgenal carina with a few minute spinules. Crown with 12 regularly distributed spines; first dorsal and first ventral shorter than remaining; largest spine 0.10 mm long. Seta 16-C situated mesially from crown. Mandible with darkly pigmented teeth; apical tooth 1.55 times as long as first dorsal tooth; seta 3-Mn 0.28 length of 4-Mn; lacinia mobilis with 7 blades; mandibular lobe small, darkly pigmented, apart from teeth. Sensilla: 10-C, 12-C, 13-C, and 16-C unknown; 9-C short, simple; 11-C short, fan-like; 14-C short, simple; 15-C short, fan-like. 0a-Mn short, fan-like; 0b-Mn elongate, simple. 6-Mx short, fan-like; 4-Mx unknown, 5-Mx short, fan-like.

SIPHON. 0.30 mm long. Seta 1 fan-like, at about 0.23 of length from base. 6-S and 9-S lightly colored; length of 6-S/9-S: 0.86.

Pupa (n = 1)

EXUVIA ( Fig. 16F ). Uniformly light brown; setae moderately dark pigmented.

CEPHALOTHORAX. Length 1.01 mm. Respiratory organ ( Fig. 16G ) flattened, wide, somewhat bilobed, 0.53 mm long longitudinally. Dorsal seta 1 moderately elongate, thick, one length apart from dorsal 2; dorsal 2 slightly longer, less thick; both setae arising from undifferentiated cuticle. Supraalar 2 and metathoracic setae absent.

ABDOMEN ( Fig. 16H ). Moderately elongate, tapering, integument dorsolaterally rough; length of segments I–VIII 0.98 mm, width/length: 0.75. Margins serrate, strongly projected posterolaterally. Dorsal setae short, about 0.25 length of respective segments, equal from III–VII. Lateral setae L-4 elongate, longer than respective segments. Largest seta L-4-VI, 1.6 length of segment. Terminal process elongate, basal width 0.42 of length, with broad paddles; D-1-IX short, at about 0.7 length from base; apical spine not articulated; lacking ventroapical seta V-1-IX; female genital lobe round, occupying almost all basal portion. Chaetotaxy as illustrated.

Distribution and biology

This is a new record both for Bahia state and the Brazilian Northeast region. Individuals were collected as immatures in ground pools of a white-sandy tropical savanna patch inside a fragment of lowland Atlantic forest (mussununga ecosystem), and as adults in frog-call pan traps, light traps and one specimen captured biting a Boana faber ( Fig. 1 ). Altitudes range from 72 to 89 m a.s.l. The specimens from Santa Catarina have previously been reported by Amaral et al. (2019).

Corethrella peruviana is otherwise recorded from Costa Rica, Panama, Colombia, Venezuela, Trinidad and Tobago, Guyana, Equador, Peru and the Brazilian states of PA, SC, and SP, at altitudes ranging from 0 to 269 m a.s.l. ( Borkent 2008; Amaral et al. 2019).

Remarks

The adult specimens here examined match the description by Borkent (2008) (see the discussion about the dorsocentral row in the Morphology remarks section). The description by Lane & Aitken (1956) of the immatures of Lutzomiops juquiana Lane, 1939 later considered a junior synonym of C. peruviana Lane, 1939 ( Borkent 2008) , also correspond to the specimens in hand, differing only in the number of teeth in the larval prementum (11).

Figures

Fig. 1. Female adult Corethrella peruviana Lane, 1939 biting a male Boana faber (Wied-Neuwied, 1821), Porto Seguro, Bahia, 30 Aug. 2019.

Fig. 16. Corethrella peruviana Lane, 1939. A. Adult cranial setae, anterior and posterior views, and female clypeus in anterior view. B. Adult thoracic setae, lateral view. C. Hind leg claw and empodium, lateral view. D. Larval exuvia, ventral view, in two pieces. E. Exuvia of larval head, ventral view, except mandible in dorsal view. F. Pupal exuvia, dorsal view. G. Pupal respiratory organ, dorsal view. H. Pupal methatorax and abdomen, dorsal and ventral views. Scale bars: 0.2 mm.