Longivena, a new robber-fly genus from Brazil (Diptera, Asilidae, Asilinae)

Abstract Longivena gen. n. and five new species are described and illustrated from caatinga and cerrado habitats from Brazil: Longivena digitata sp. n., type–species (Maranhão, Bahia, Minas Gerais and Mato Grosso do Sul states), Longivena bilobata sp. n. (Maranhão state), Longivena flava sp. n. (Mato Grosso do Sul state), Longivena limeiraoliverai sp. n. (Maranhão state), Longivena spatulata sp. n. (Maranhão state). An illustrated key is also provided.


Introduction
There are 178 currently known genera of Asilinae Latreille, 1802, of which 67 are known from the Neotropical region and 19 from Brazil (Vieira 2012a, Artigas and Vieira 2014, Vieira and Ayala 2014. Due to the great similarity found between members of Asilinae, some artificial generic groups have been proposed to fascilitate identification (Artigas and Papavero 1997a). These groups were established based mainly on male and female terminalia, since external characters are insufficient to separate genera.
In this paper, a new robber fly genus, Longivena gen. n., is proposed. This genus is morphologically similar to the genera of the artificial group Efferia and is characterized by the r3 cell closed and petiolate and the long stump vein (supernumerary crossvein) on R 4 reaching the base of R 2+3 . This paper presents a description, diagnoses, illustrations of a new genus of Asilinae, and comments on related genera.

Material and methods
This study is based on the examination of specimens housed in the following institutions: CZMA -Coleção Zoológica do Maranhão, Universidade Estadual do Maranhão, Caxias, Maranhão state, Brazil (Dr Francisco Limeira-de-Oliveira) and Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas state, Brazil (Dr Marcio Oliveira). Morphological terminology follows Cumming and Wood (2009). Vieira's (2012b) techniques were used to examine the terminalia. After examination and illustration, the detached parts were placed in microvials with glycerin and pinned along the same pin with their respective specimen. Standard measurements were taken utilizing a filar micrometer. Label data is cited in full, with the original spellings, punctuations, and dates. Information presented within square brackets is complementary data not included on the labels. Data for the same specimen but from different labels are separated by slashes (/). The map was generated with software SimpleMappr.
Etymology. From Latin, longi = long + vena= vein, referring to the long stump vein (supernumerary crossvein) on R 4 that reaches the base of R 2+3 .
Wing (Fig. 3). Brown. Crossvein r-m passes slightly beyond middle of discal cell; halter yellow. Legs (Fig. 1). Femora wholly black. Fore tibia black; mid tibia dark brown to black anteriorly and yellow posteriorly; hind tibia, anteriorly, with basal 4/5 yellow and apical 1/5 black with a brown stripe, and with basal 2/3 yellow and apical 1/3 brown posteriorly. Fore femur with yellow ventral setae; mid femur with five black anteroventral Obs. The small crosssvein connecting stump vein with R 2+3 is an anomaly 4 Terminalia, lateral view treated in hot 10% KOH 5 Sternite VIII 6 Gonocoxite and gonostylus 7 Apex of gonostylus setae, with one black apical seta dorsoposteriorly; hind femur with two yellow and one black macrosetae anteriorly, three yellow on basal 1/2 and three black macrosetae on apical 1/2 anteroventrally, and one apical black macrosetae posterodorsally; fore tibia with two black setae posteriorly; mid tibia with one long, black anteroventral seta; hind tibia with three black anterodorsal and two anteroventral setae; tarsomeres with black setae.
Etymology. From Latin, bi = two + lobus = lobe, referring to the bilobate apex of the epandrium.
Holotype conditions. Left detached wing mounted on microslides, terminalia placed in microvial with glycerin and pinned along with the specimen.
Male. Holotype. Head. Scape and pedicel black, postpedicel dark brown to black; six setae and two ocellar macrosetae; vertex black, sparsely golden tomentose; frons black; face black, golden tomentose; mystax mostly with black macrosetae and a few golden macrosetae on oral margin; palpus with yellow to brown setae; proboscis black with yellow ventral setae; labial setae yellowish; occiput black, sparsely gray tomentose, with yellow setae; eight to nine postocular macrosetae.
Wing (Fig. 12). Brown. Crossvein r-m basal to middle of discal cell; halter yellow. Legs (Fig. 10). Femora black; fore tibia black anteriorly and dorsally, brown ventrally, mixed black and brown posteriorly; mid tibia mostly brown, except for a black stripe anteriorly and black apex dorsally; hind tibia brown, black posteroapically; first tarsomere: fore black, mid dark brown and hind brown. Fore femur with only yellow ventral setae; mid femur with three black apical macrosetae, and yellow and black ventral setae; two yellow, basal and preapical, macrosetae posteriorly; hind femur with two yellow and one black macrosetae anteriorly, four yellow basal and two to three medioapical macrosetae anteroventrally; fore tibia with four yellow posteroventral setae on right leg and three yellow and one black apical setae on left leg; mid tibia with three yellow setae; hind tibia with five yellow setae dorsally, two to three black setae anteriorly, one yellow preapical seta ventrally; fore and mid tarsus with one yellow seta, hind tarsus with one to two yellow setae.
Length. Body 12.2 mm; wing 8.1 mm. Holotype conditions. Two ocellar setae lost; some mystax setae broken; one left dorsocentral macroseta lost; cells r4 and r5 punctured apically; right mid tibia with one seta broken and another lost; right hind femur with two anteroventral setae broken and left hind femur with three anteroventral macrosetae broken. Left detached wing mounted on microslides, terminalia placed in microvial with glycerin and pinned along with the specimen.  Variation (n= 12): Body length 13.3-14.9 mm, wing 8.4-9.5 mm; three to seven ocellar setae; frons black, golden tomentose; five to seven postocular macrosetae; five pairs of postsutural dorsocentral macrosetae; one macrosetae and one, or two, apical scutellar setae; two black supra-alar macrosetae; halter stem yellow and capitulum reddish; mid femur with a black seta anteriorly; hind femur with three yellow macrosetae anteriorly, and four yellow and one to two anteroventrally; fore tibia with three to four yellow and one black setae posteroventrally; mid tibia with four yellow setae; hind tibia with two yellow setae anteriorly and one preapical ventrally; mid tarsus with black setae; tergites II-IV gray tomentose laterally; sternites II-VI gray tomentose.
Female (Figs 19-22): Similar to male, except for body length: 13.5-17.2 mm, wing 9.3-9.9 mm; six to eight postocular macrosetae; face dark brown, golden tomentose (Fig. 20); three to four pairs of postsutural dorsocentral macrosetae; one to two supra-alar macrosetae; no apical scutellar seta, except in one paratype that has one macroseta and one seta, and another that has only one seta; one paratype with fore basal tarsomere dark brown, mid and hind basal tarsomeres brown. Mid femur with one to three black macrosetae anteriorly (one paratype with three yellow macrosetae); hind femur with at most two yellow and one to two black macrosetae anteriorly (two paratypes with three yellow macrosetae, one of them with an additional black seta); hind femur with at most two black and four to five yellow macrosetae anteroventrally; fore tibia with three to four yellow setae posteroventrally (one paratype with two yellow and two black setae on left fore tibia); mid tibia with two to four yellow setae; hind tibia with four to five yellow setae dorsally (one paratype specimen with two yellow and one black setae anteriorly, one preapical and one yellow seta medioventrally); tarsomeres with only black setae, except for one paratype that has one yellow seta on fore and mid tarsomeres; hind tarsomere with one to two yellow setae; abdominal tergites I-VI brown, golden tomentose laterally; tergite VII black, golden tomentose laterally; tergite VIII dark brown, long and slender (Figs 19,21); tergite IX + X membranous posteromedially; three spermathecal capsules oval and sclerotized (Fig. 22).
Etymology: From Latin digitata = digitate, finger-like, referring to the shape of the gonocoxite's apex.
Wing (Fig. 3). Crossvein r-m basal to middle of discal cell; halter whitish-yellow. Legs (Fig. 25). Light yellow, except apex femora black. Fore femur with thin and yellow ventral setae; mid femur with three black anterior setae; hind femur with three yellow anterior setae, two yellow and three black anteroventral setae, and preapical dorsal region with one black anterior macroseta and one yellow posterior macroseta; fore tibia with two to three yellow and one black posterior macrosetae; mid tibia with two long black anteroventral setae; hind tibia with three black and one yellow anterior setae; hind tibia with a group of short, yellow, spiniform setae, in a row from the base of the tibia and continuing until the fourth tarsomere; fore and mid tarsomeres with black setae; hind tarsomeres with mostly black setae, except for two yellow setae apically on the first tarsomere.
Length. Body 12.2 mm; wing 9.2 mm. Female. Unknown. Holotype conditions. left wing slightly wrinkled; right katatergite and left posterior basalare sclerite punctured; right mid leg glued onto thorax; hind tibiae crushed medially. Right detached wing mounted on microslides, terminalia placed in microvial with glycerin and pinned along with the specimen.
Wing (Fig. 34). Brown. Crossvein r-m passes slightly beyond middle of discal cell; halter yellow. Legs (Fig. 32). Wholly black. Fore femur with yellow and black setae ventrally; mid femur with yellow setae ventrally, with one black apical macroseta posterodorsally; hind femur with four black setae and one black macroseta anteroventrally, and three black macrosetae anteriorly; fore tibia with four black setae posteriorly; mid tibia with three yellow setae posteriorly; hind tibia with two black macrosetae posteriorly; tarsomeres with black setae.
Length. Body 10.1 mm; wing 6.8 mm. Holotype conditions. Left detached wing mounted on microslides, terminalia placed in microvial with glycerin and pinned along with the specimen.
Etymology. A patronym to the researcher Francisco Limeira-de-Oliveira, PhD at Universidade Estadual do Maranhão.
Wing (Fig. 43). Brown. Crossvein r-m passes slightly beyond middle of discal cell; halter with yellow stem and dark red capitulum. Legs (Fig. 41). Femora black; fore tibia black anteriorly, brown ventrally, and with basal 1/2 brown and apical 1/2 black posterodorsally; mid tibia with basal 2/3 brown and apical 1/3 black anteriorly, remaining brown (except apex black); hind tibia brown, black posteroapically; tarsomeres brown, except for black apical ones. Fore femur with only yellow setae ventrally; mid femur with a yellow macroseta anteromedially and two black macrosetae apically and one yellow apical seta posterodorsally; hind femur with three yellow macrosetae anteriorly, three yellow setae basally, and three black macrosetae apically, one black preapical macroseta anterodorsally and one yellow preapical macroseta posterodorsally; fore tibia with four yellow setae posteriorly; mid tibia with two black setae anteriorly and three yellow setae posteriorly; hind tibia with three yellow setae anteriorly and three posteriorly; tarsomeres with black setae, except for one yellow seta on the first tarsomere of the right mid leg.
Length. Body 15.3 mm; wing 10.2 mm. Holotype conditions. Left hind leg lost; part of tergite I separated from thorax. Right detached wing mounted on microslides, terminalia placed in microvial with glycerin and pinned along with the specimen. Female. Unknown. Etymology, From Latin spatulata = spatulated, referring to the shape of the gonocoxite apex.
Longivena gen. n. and Eichoichemus are sister taxa sharing the synapomorphy: suture between labella and prementum strongly appressed, situated dorsally and five additional apomorphic character states: anterior tentorial pits small, slitlike, inconspicuous, ventrally located; presutural acrostichal setae in regular rows; postmetacoxal bridge absent, postmetacoxal area entirely membranous; stump vein supernumerary crossvein on R 4 present, length intermediate (1/5-1/6 of vein R 2+3 ); costal section on between tip of R 5 and tip of M 1 shorter than costal section between tips of R 1 and R 5 .
Biology. Little is known about the biology of species of Longivena gen. n.. The species were collected with either light or Malaise traps. Only the female of L. digitata has been collected to this day. It is expected that with future collecting efforts, new species of Longivena gen. n. will be found as well as the females of the species described in this paper.
Distribution. The species of Longivena gen. n. were found in the Caatinga (Longivena digitata sp. n.) and Cerrado (L. bilobata sp. n., L. flava sp. n., L. limeiraoliverai sp. n. and L. spatulata sp. n.) habitats or environments. Caatinga is a region characterized by arboreal or bushy forests, having mainly small trees and bushes which bear spines and some xerophytic characteristics, average annual precipitation below 800 mm and, at most, a 0.5 aridity index (Prado 2003) and Cerrado biomes is a region characterized by a savannah-like vegetation, with a seasonal climate, with heavy rains between the months of October and March and a long dry period between June and September (Harley et al. 2005).