Mexican species of Labena Cresson ( Hymenoptera , Ichneumonidae ) with description of a new species

Nine species of the genus Labena Cresson are recorded from México. One species, Labena acerba sp. n., is described as new. Two species, L. eremica Gauld and L. marginata Szépl., are recorded from México for the fi rst time. New data on distribution of Labena in México are provided. A key to Mexican species of


Introduction
Labena Cresson, 1864 is a large, predominantly Australian and Neotropical genus with 37 described species (Yu et al. 2005).Seven species are known from Australia (Gauld and Holloway 1986), two species occur in the U.S.A. and Canada (Townes and Townes 1960), 21 in Costa Rica (Gauld 2000), and 11 in South America, including Bermuda and Grenada (Townes andTownes 1966, Yu et al. 2005).Th e real number of Neotropical species is much greater, Gauld (2000) mentioned at least 50 species for this region.Townes and Townes (1966) in their Catalogue of Neotropic Ichneumonidae listed two species of Labena for México, L. gloriosa Cresson and L. grallator (Say); the fi rst one was described from México.Gauld (2000), in his study of Ichneumonidae of Costa Rica, recorded for México two species of this genus, L. gloriosa and L. schausi Cushman, among 21 Costa Rican species.In a paper on Mexican Labeninae and Brachycyrtinae (Hernández et al. 2000), L. espinita Gauld, L. schausi, L tarsata Gauld, L. zerita Gauld and one species mentioned as "Labena sp.n." were listed (the last species is considered to be a variation of L. tarsata in this paper).Th e latest paper on Mexican Ichneumonidae with data on the genus Labena (Ruíz-Cancino et al. 2002) includes 5 species of this genus, four species from the preceding paper and L. gloriosa.
One species, Labena acerba sp.n., is described in this paper as new.Th is species is similar to the Costa Rican L. guanacasteca Gauld as both have the fi rst sternite with distinct transverse ridge centrally (Fig. 4), a notable synapomorphy unknown in other species, but diff ers in its black fl agellum (Fig. 3), area superomedia + petiolaris shorter (Fig. 5), and body entirely yellow without black markings.Two more species, L. eremica Gauld and L. marginata Szépl., are recorded for the fi rst time for México.A variation of L. tarsata with a darker metasoma and propodeum partly carinate is discussed.
A key to nine Mexican species of Labena is provided and new data on distribution are presented.All of the species were examined from Mexican material with the exception of L. gloriosa and L. grallator, for which material was not available.
Species of Labena are known as ectoparasitoids of various wood-boring Coleoptera.Among the Mexican species, only L. grallator has host records.

Methods
Th is work is based on the material of the Universidad Autónoma de Tamaulipas in Cd.Victoria, México.Taxonomy is accepted as in the software program TaxaPad (Yu et al. 2005).Morphological terminology follows Gauld (2000).Photos were taken with a Leica MZ16 stereomicroscope with integrated Leica photo camera in the Zoological Institute of the Russian Academy of Sciences (St. Petersburg, Russia).Th e captured images were assembled with Helicon Focus software and edited in Adobe Photoshop CS2.Th e holotype of the new species was obtained from Dr A. González Hernández (Universidad Autónoma de Nuevo León, Monterrey, México) and is deposited at the Universidad Autónoma de Tamaulipas, Cd.Victoria, México.First sternite with a distinct central transverse ridge (Fig. 4).Propodeum with area superomedia open posteriorly, broadly confl uent with area petiolaris (Fig. 5).Head in dorsal view with gena strongly narrowed behind eyes (Fig. 2).Mid leg in female with second tarsomere longer than broad, longer than third and fourth tarsomeres together.Tergites 3-5 in male strongly transverse, with hind margin conspicuously concave (male of L. acerba sp.n. unknown) ... 15 15.

Key to Mexican species of
Flagellum almost entirely black, narrowly yellowish basally and apically, without a pale median band (Fig. 3).Propodeal area which is comprised by the confl uent areas superomedia and petiolaris slightly transverse, 0.9 times as long as maximally broad (Fig. 5).Body yellow except for three brownish longitudinal marks on mesoscutum .Diagnosis.Th e new species is very similar to the Costa Rican L. guanacasteca Gauld as both have a fore wing without an apical black spot, a propodeum with area superomedia open posteriorly and broadly confl uent with area petiolaris (Fig. 5), and a fi rst sternite with distinct transverse ridge centrally (Fig. 4).Unlike this species L. acerba sp.n. has a black fl agellum, without a pale median band (Fig. 3), a shorter area superomedia + petiolaris of propodeum (Fig. 5), and a yellow body without any black marks.Th e new species can be distinguished from all Mexican species of Labena by the following characters in combination: 1) mesopleuron polished, impunctate, 2) fore wing without an apical spot, 3) fi rst sternite with a transverse ridge, 4) fl agellum extensively black, without a central yellowish band.Description.Female.Fore wing length 9.3 mm.Mandible evenly tapered towards distal end, upper tooth much longer than lower tooth.Clypeus almost fl at, twice as broad as high, with lower margin distinctly convex centrally.Malar space 0.3 times as long as basal width of mandible.Face with median vertical ridge (also reaching between antennal sockets) which has radiating, parallel rugae, and with a pair of lateral vertical carinae (along eye margins).Frons fl at, dull, with scattered fi ne punctures.Vertex and temple smooth.Head in dorsal view with gena short, abruptly rounded behind eyes (Fig. 2); lower part of gena very broad.Posterior ocellus separated from eye by 1.4 times its own maximum diameter.Inner margin of eye with a strong concavity opposite antennal insertion (Fig. 1).Occipital carina complete, reaching hypostomal carina far from base of mandible, strongly raised between base of mandible and its junction with hypostomal carina.Flagellum of antenna with 42 segments; subbasal fl agellomeres more or less elongate, median and subapical ones transverse, apical fl agellomere subtriangular with apex truncate.
Mid leg with tibia infl ated in distal 0.7, with slender bristles on outer surface, second tarsomere about twice as long as broad, longer than following two tarsomeres.Hind coxa about twice as long as deep.
Fore wing with areolet transverse, with 2rs-m longer than 3rs-m.First tergite 1.6 times as long as posteriorly broad, depressed, without dorsolateral carina behind spiracle; sternite short, reaching 0.3 of length of tergite, with transverse ridge centrally (Fig. 4).Second tergite strongly transverse, 0.56 times as long as posteriorly broad.Ovipositor straight, compressed, almost twice as long as hind tibia.
Coloration: Yellow species.Mandible black apically.Antenna black, with base and apex yellowish (Fig. 3).Head slightly darkened around ocelli.Face and metasomal tergites with scattered reddish specks (more dense on face).Mesoscutum with three brownish longitudinal marks.Hind leg with tibia apically and tarsus posteriorly fuscous.Pterostigma yellow-brown.Ovipositor dark red, its sheath yellowish brown basally to fuscous apically.