Memórias do Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Fiocruz ISSN: 1678-8060 EISSN: 1678-8060 Vol. 89, Num. 2, 1994

Two New Neotropical Species of Monohelea Kieffer and Downeshelea Wirth & Grogan (Diptera: Ceratopogonidae)

Maria Luiza Felippe-Bauer, Gustavo R Spinelli (*)

Code Number: OC94034
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Departamento de Entomologia, Instituto Oswaldo Cruz, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brasil (*) Instituto de Limnologia "Dr. Raul A. Ringuelet", Casilla de Correo 712, 1900 La Plata, Argentina

Two new Neotropical predaceous midges are described and illustrated, Downeshelea charrua from Uruguay, and Monohelea bidentata from Argentina. The first species is described from female and male specimens; only one male is known from the second.

Key words: Neotropical predaceous midges - Downeshelea charrua sp.n. - Monohelea bidentata sp.n.

Both genera, Downeshelea Wirth & Grogan and Monohelea Kieffer exhibit a worldwide distribution. Thirteen species of each genus have been recorded from the Neotropical region (Wirth 1974, Wirth & Grogan 1988), but none of them for Argentina and/or Uruguay.

In this paper we described two new species, Downeshelea charrua from the Department of Salto, Uruguay and Monohelea bidentata from the Province of Buenos Aires, Argentina.

The terminology used is that adopted by Wirth and Williams (1964) for North American species of Monohelea, Lane and Wirth (1964) for Neotropical species and Ratanaworabhan and Wirth (1972) for Oriental species.

Downeshelea charrua Felippe-Bauer & Spinelli new species (Figs 1, 2 - 11)

Type locality: El Espinillar, Salto, Uruguay.

Female Allotype: wing length 1.56 mm;

breadth 0.62 mm.

Head: reddish-brown. Eyes (Fig. 3) bare, narrowly contiguous in lower portion. Antenna (Fig. 4) brown, bases of flagellomeres 1-10 pale; flagellomeres cylindrical, with lengths in proportion of 35-23-25-26-26-27-27-27-39-39-40-43-53; A.R. (11-15/3-10) 0.99. Palpus (Fig. 7) uni-formly brown, slightly longer than proboscis; lengths of segments in proportion of 14-25-30-25-22; 3rd segment cylindrical, with a small, shallow, rounded sensory organ in mid portion; P.R. 2.5. Mandible with 11-12 teeth.

Thorax: scutum golden brown, humeral pits whitish; scutellum dark in middle, with four strong setae. Legs (Fig. 5) brown, the hind slightly darker; basal 3/4 of mid femur and basal 2/3 of hind femur paler, knees yellowish; fore and hind tibiae with apical spur, longer in fore leg; hind tibial comb with eight bristles; lengths of trochanters, femora and tibiae of fore, mid and hind legs in proportion of 15-70-70, 15-85-85, 15-100-95. Tarsi (Fig. 6) pale, pilose; ventral palisade setae in one row on hind basitarsus; fore and hind basitarsi with one basal and one apical spine; mid basitarsus with 2 basal, 2 apical and 3-4 ventral spines; apical spines of tarsomeres 2-4 of fore, mid and hind legs as follows: 1-2-2, 2-2-2, 1-1-2, basal spines absent; lengths of fore, mid and hind tarsomeres in proportion of 35-16- 11-8-13, 41-16-12-7-14, 55-25-15-10-21; fore, mid and hind tarsal ratios 2.2, 2.6, 2.2; claws of fore and mid legs paired, equal sized, about 0.6 times as long as 5th tarsomere; hind leg with a single claw, about 1.4 times as long as 5th tarsomere. Wing (Fig. 1) hyaline, scattered macrotrichia distally in cells R5 and M1, microtrichia absent; 2 conspicuous dark spots, one located on the r-m crossvein reaching the medial fork (where is much darker), the other in cell R5, extending from the end of 2nd radial cell to vein M1; 6 inconspicuous grayish, difuse areas in apical portions of cells R5, M1, M2 (this one reaching vein M2) and M4, and veins M1 and Cu1; 2nd radial cell nearly twice as long as 1st; costal ratio 0.78. Halter knob dark brown.

Abdomen: brown. Two ovoid spermathecae (Fig. 9), slightly unequal, measuring 0.069 by 0.048 mm, and 0.053 by 0.048 mm; a vestigial 3rd present, 0.018 mm long.

Male Holotype: wing length 1.40 mm; breadth 0.46 mm. Similar to female with usual sexual differences; antenna with brown pedicel, flagellomeres pale brown except flagellomeres 13-15 brown; 4-11 somewhat barrel-shaped, 12 nearly twice as long as wide, 13-15 elongated, lengths of flagellomeres in proportion of 64-22-22-22- 20-20-20-20-20-27-63-51-47; A.R. (12-15/3-11) 0.82. Palpus uniformly brown; lengths of segments in proportion of 12-24-26-23- 28; P.R. 2.6. Lengths of trochanters, femora and tibiae of fore, mid and hind legs in proportion of 14-65-64, 13-77-75, 14-84-80. Tarsi pale, pilose; fore basitarsus with one basal and one apical spine; mid basitarsus with 2 basal, 2 apical and 2- 4 ventral spines; hind basitarsus with one basal and 2 apical spines; apical spines of tarsomeres 2-4 of fore, mid and hind legs as follows: 1-2-1, 2-2-2, 2-1-1, basal spines absent; lengths of fore, mid and hind tarsomeres in proportion of 32-16- 12-8-10, 40-17-11-8-9, 48-22-17-10-11; fore, mid and hind tarsal ratios 2.0, 2.3, 2.2; claws paired, equal-sized, about 0.4 times as long as 5th tarsomeres. Wing (Fig. 2) hyaline, dark spots as in female, costal ratio 0.73. Genitalia (Fig. 8): posterior margin of 9th sternum with two long hairs; 9th tergum tapered, with a pair of very short apicolateral processes. Gonocoxite nearly 2.4 times as long as basal wide; gonostylus nearly straight, gradually narrowed to apex, about 0.68 times as long as gonocoxite, moderatelly pilose basally. Aedeagus (Fig. 11) triangular, basal arch extending to 0.3 of total length; lateral arms strongly sclerotized; distal portion with two long, slender, sclerotized processes, each with blunt apex. Parameres (Fig. 10) H-shaped, each lateral sclerite with strongly sclerotized, trilobed basal arm; main portion stout, nearly straight, 0.85 times as long as aedeagus, apices mesally curved.

Distribution: known only from the type locality.

Types: holotype male, allotype female, El Espinillar, Salto, URUGUAY, 24.IV.1985, G. Spinelli coll. In the collection of the Museo de La Plata, Argentina.

Etymology: the specific epithet refers to the Charrua indians, early inhabitants of the type locality.

Discussion: Downeshelea charrua most closely resembles D. fuscipennis (Lane & Wirth), D. castroi (Tavares & Pereira) and D. cebacoi (Lane & Wirth) by similar wing pattern, which exhibits a distinctive dark spot apically in cells R5 and M1. They can be easily separated by the shape of aedeagus and parameres. Furthermore, in D. charrua the aedeagus is longer than the parameres, while in D. fuscipennis, D. castroi and D. cebacoi it is smaller.

Monohelea bidentata Felipe-Bauer & Spinelli

new species (Figs 12-17)

Type locality: Punta Lara, Buenos Aires, Argentina.

Male Holotype: wing length 1.21 mm; breadth 0.38 mm.

Head: dark brown. Eyes bare, separated by a distance equal to diameter of 2 ommatidial facets. Antenna yellowish, pedicel and flagellomeres 13-15 brown; 4-11 somewhat barrel-shaped, 12 about three times as long as wide, 13-15 elongated; lengths of flagellomeres in proportion of 54-17-17-15-15-15-15-15-15-20-55- 55-51; A.R. 1.0. Palpus uniformly pale brown; lengths of segments in proportion of 14-17-18-14-25; 3rd segment ovoid; P.R. 2.0.

Thorax: scutum golden brown, humeral pits whitish. Legs (Fig. 14) brown, hind leg slightly darker; proximal 1/2 of femora dark; fore and hind femora with a narrow, oblique, dark brown stripe in middle, and a subapical, dorsal, dark brown mark; knees yellowish; apices of tibiae dark brown, fore tibiae dark mesally hind tibiae broadly dark brown basally; fore and hind tibiae with apical spur, longer in fore leg; hind tibial comb with 6 bristles; lengths of trochanters, femora and tibiae of fore, mid and hind legs in proportion of 11-50-51, 11-61-56, 12-67-65. Tarsi (Fig. 16) pale, pilose; ventral palisade setae in one row on hind basitarsus; fore and hind basitarsi with one basal and one apical spine, mid basitarsus with 2 basal and 2 apical spines; apical spines of tarsomeres 2-4 of fore, mid and hind legs as follows: 1-1-1, 2-2-2, 1-1-1, basal spines absent; lengths of fore, mid and hind tarsomeres in proportion of 27-14- 10-7-7, 36-15-9-7-7, 34-16-11-9-7; fore, mid and hind tarsal ratios 1.9 - 2.4 - 2.1; claws paired, equal-sized, about 0.4 times as long as 5th tarsomeres. Wing (Fig. 12) with irregular dark areas and spots, defining the hieroglyphic pattern; macrotrichia absent; 2nd radial cell nearly twice as long as 1st; costal ratio 0.79. Halter stem pale, apical 1/2 of knob brown.

Abdomen: brown, segments 1-2 yellow. Genitalia (Fig. 13): yellowish. Ninth tergum tapered, with a pair of short apicolateral processes. Gonocoxite moderately stout, nearly twice as long as basal wide, with a prominent internal lobe; gonostylus nearly straight, slightly shorter than gonocoxite, gradually narrowing to apex, moderately pilose basally, tip dark. Aedeagus (Fig. 15) triangular with 2 pointed ventral plates, and a slightly sclerotized dorsal structure produced beyond apices of ventral plates; it is also present an apical, hyaline, scape-shaped structure, which reachs the end of 9th tergum. Parameres (Fig. 17) as long as aedeagus, separated; each with strongly sclerotized, nearly straight, mesally directed lateral arms; distal portion with a pair of tooth-shaped processes, their bases internally directed.

Female: unknown.

Distribution: known only from the type locality.

Type: holotype male, Punta Lara, Buenos Aires, ARGENTINA, 29.X.1985, G. Spinelli coll. In the collection of the Museo de La Plata, Argentina.

Etymology: the specific epithet is from the Latin: bi=two, and dentis=tooth, referring the apical tooth-shaped processes of parameres.

Discussion: Monohelea bidentata most closely resembles M. maculipennis (Coquillett) by the wing and legs patterns. It can be readily separated from M. maculipennis by the distinct parameres with apical tooth-shaped processes, and by the aedeagus with an apical, hyaline, scape-shaped structure.

ACKNOWLEDGEMENTS

To Dr OP Forattini, Faculdade de Saude Publica, Universidade de Sao Paulo, for the loan of material of Downeshelea and Monohelea for study; to Dr OM Barth and MPR Costa, Instituto Oswaldo Cruz, for their help with wing photographs.

REFERENCES

Lane J, Wirth WW 1964. The biting midge genus Monohelea Kieffer in the Neotropical Region (Diptera: Ceratopogonidae). Studia Ent 7: 209-236.

Ratanaworabhan NC, Wirth WW 1972. The biting midge genus Monohelea Kieffer in the Oriental Region (Diptera: Ceratopogonidae). Pacif Ins 14: 439-473.

Tavares O, Souza SA 1980. Duas especies novas do genero Monohelea Kieffer, 1917, do Estado do Rio de Janeiro, Brasil (Diptera: Ceratopogonidae). Rev Brasil Biol 40: 95-100.

Wirth WW 1974. A catalogue of the Diptera of the Americas south of the United States 14. Ceratopogonidae. Museu de Zoologia. Univ. Sao Paulo, 89 pp.

Wirth WW, Grogan Jr WL 1988. The predaceus midges of the World (Diptera: Ceratopogonidae, Tribe Ceratopogonini). Flora and Fauna handbook No. 4, EJ Brill, 160 pp.

Wirth WW, Williams RW 1964. New species and records of North American Monohelea (Diptera: Ceratopogonidae). Ann Ent Soc Amer 57: 302-310.

Copyright 1994 Fundacao Oswaldo Cruz - FIOCRUZ

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