Description of the male of Hymenoepimecis bicolor ( Brullé , 1846 ) ( Hymenoptera , Ichneumonidae , Pimplinae )

aInstituto de Ciências Exatas e da Natureza – ICEN, Universidade da Integração Internacional da Lusofonia Afro-Brasileira – UNILAB, Rodovia CE 060, Km 51, CEP 62785-000, Acarape, CE, Brasil bDepartamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Carlos – UFSCar, Rodovia Washington Luís, Km 235, CP 676, CEP 13565-905, São Carlos, SP, Brasil cDepartamento de Biologia Animal, Universidade Estadual de Campinas – UNICAMP, Rua Monteiro Lobato, 255, CEP 13083-862, Campinas, SP, Brasil dPrograma de Pós-graduação em Entomologia, Instituto Nacional de Pesquisas da Amazônia – INPA, Av. André Araújo, 2936, CEP 69060-001, Manaus, AM, Brasil


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Wasps of the Polysphincta genus-group (sensu Wahl andGauld, 1998 or Polysphinctini sensu Towens, 1969) presents more than 200 described species (Matsumoto, 2016) exclusively koinobiont ectoparasitoids of several spider families (Dubois et al., 2002;Gauld and Dubois, 2006;Matsumoto, 2016).Most of taxonomic descriptions of polysphinctine wasps were based on female individuals, principally due to the presence of the ovipositor (see Gauld, 1991;Gauld et al., 1998Gauld et al., , 2002)).Meantime, some interactions of these hymenopteran with spiders were documented only with emerged males (e. g.Sobczak et al., 2011Sobczak et al., , 2017;;Sobczak, 2012), hindering the association between males and females within the group.Sobczak et al. (2017) emphasized the importance of detailed descriptions of male genitalia to support future reviews and phylogenetic studies.
Currently, Hymenoepimecis is composed by 20 valid species (Yu et al., 2012;Pádua et al., 2015), of which 12 are known as parasitoids of spiders (summarized in Pádua et al., 2016).Regarding these interactions, it is known that the larva of some wasp species can induce the host spider to construct a modified web (cocoon web), which is subsequently used as substrate for the wasp larva's cocoon (Eberhard, 2000a(Eberhard, , b, 2001;;Sobczak et al., 2009Sobczak et al., , 2014;;Gonzaga et al., 2010;).The modified web is usually more stable and resistant than the normal web, increasing the wasp survival (Eberhard, 2001).Gonzaga et al. (2010) described the interaction involving the spider Nephila clavipes (Linnaeus, 1767) (Araneidae) and the wasp Hymenoepimecis bicolor (Brullé, 1846), which follows the pattern of behavioral manipulation described above (Gonzaga et al., 2010).
Although relative well investigated on its natural history and ecology, taxonomy of H. bicolor is still restricted to the female description.Thus, in this study we described and illustrated the male of H. bicolor, with detailed description of genital capsule.
To describe the adult male of H. bicolor and compare its morphology with female's characteristics, specimens deposited at the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia, Manaus (INPA; curator M. L. Oliveira) were examined.It was used the morphological terminology and description style according to Gauld (1991), and terminology for male genitalia followed Snodgrass (1941).Pictures were taken with a Leica DFC295 digital camera attached to a Leica M205C stereomicroscope and combined with the software Leica Application Suite (Version 4.0.0).The male genitalia were extracted and submerged in 10% potassium hydroxide at room temperature for clarification.To draw the genital capsule, a Leica DM750 microscope, with posterior digital vectorization was used.
Taxonomy Hymenoepimecis bicolor (Brullé, 1846) (Figures 1A, B) Epimecis bicolor Brullé, 1846: 113.Hymenoepimecis bicolor (Brullé) Viereck, 1912: 149.Male (Figure 1A): Length: 8.9-14 mm.Fore wings: 6.6-8.9 mm.Antenna with 33-38 flagellomeres, lower face about 0.7-1.0 times as broad as high, with scattered hairs, coriaceous and striated transversally, presence of small tubercle below the base of scapus; head in dorsal view (Figure 1B) with long gena, posterior ocelli separated from eyes by 0.75-1.2times its own maximum diameter.The distance from tegula to head is about 0.6-0.9times the distance from tegula to hind margin of propodeum, scutellum in profile convex, mesopleuron smooth and polished; propodeum smooth, polished with two lateral longitudinal carinae only posteriorly, and opening pocket-like structure with a longitudinal opening in the central surface.Metapleuron and propodeum with scattered hairs, sub metapleural carina absent.Fore wing with cu-a interstitial to base of Rs & M, 2rs-m about 0.25-0.5 times as long as abscissa of M between 2rs-m and 2m-cua, vein 3rs-m absent; hind wing with distal abscissa of Cu1 meeting cu-a closer to M than 1A.Hind tibia plus tarsus 0.55-0.7 times the fore wing length.Metasoma slender, tergite I 2.6 times as long as posteriorly broad, with convergent lateral carinae present only anteriorly; sternite I with an apically acute, thorn-like ventral projection posteriorly, tergite II-IV 1.2-1.4times as long as posteriorly broad with presence of two smooth tubercles.Subgenital plate as long as broad, with bristles evenly; sternal apodeme narrow, about 0.2 times longer than sternum (sternal apodeme plus sterno) (Figure 1C); genital capsule (Figures 1D, with paramere rounded apically, narrower than parameral lamina, with dense bristles; volsellar lamina with few bristles spaced subapically; cuspis robust, with tooth in lateral and apical parts and a bristle at the apex; digitus narrow, 0.40-0.46times the length of cuspis plus volsellar lamina, with tooth in the apex, apex rounded dorsally and angulated ventrally, its basal region slightly larger than apical region; aedeagus (including aedeagal apodeme) 0.90-0.95times the length of paramere plus parameral lamina (including the parameral apodeme); ergot about 0.27-0.37times the length of aedeagus.
Coloration: Body honey yellow.Head black, the most part of clypeus pale yellow.Tergites II-V orange with apical margin black, VI + black; sternite I smooth, brownish; II-VI light brown and coriaceous.Fore and mid legs orange, hind leg with femur, tibia and tarsi black.Wings yellowish, fore wing with apex blackish, pterostigma yellow.
Cocoon (Figure 1F): fusiform, light golden yellow (Figure 1C), remains attached to modified web of the host.To get out from the cocoon, the adult wasp uses the jaws to cut the apical part.
Variation: face smooth; opening pocket like structure without a longitudinal opening in the central surface; hind wing with distal abscissa of Cu1 meeting cu-a equidistant between 1A and M; tergites II-IV orange with two black spots in the distal corners; tergite V entirely black.
Examined material: Amazonas: Manaus, Reserva 1208, Fazenda Esteio, PDBFF, 02°22'34"S/59°52'39"W, 1 ♂, INPA;Itacoatiara, Madeireira Mil, 16.vii.1999, Malaise (J. Vidal leg.) Comments: The male genitalia of H. bicolor was compared to the other species of which male genitalia has been described so far, H. duckensis Pádua & Onody, 2015, H. manauara Pádua & Oliveira, 2015, H. ribeiroi Pádua & Sockzak, 2015, and H. uberensis Pádua & Onody, 2015(see Pádua et al., 2015).It was observed that H. bicolor differs from H. duckensis by having the volsellar lamina with few bristles spaced subapically and cuspis with bristles at the apex; H. duckensis do not have bristles at the apex in the cuspis and nor the volsellar lamina with many bristles spaced, except in posterior region.Hymenoepimecis bicolor differs from H. manauara, H. ribeiroi and H. uberensis essentially by the presence of cuspis with bristles at the apex (except H. manauara, that it is also present) and digitus narrow, rounded dorsally and angulated ventrally, with basal region slightly larger than apical region.Hymenoepimecis manauara have digitus enlarged apically and angulated basally, H. riberoi have cuspis without bristles in apex and digitus rounded apically and angulated basally, as wide as the basal region, and H. uberensis have cuspis without bristles in apex and digitus truncated apically and angulated basally.In addition to the morphological differences of the male genitalia compared in this study, the external morphological characteristics and staining of the male of H. bicolor is similar to the female and this species differs from the other Hymenoepimecis species by the following characteristics: fore wing hyaline yellowish, with apex blackish, metasoma orange, with posterior margins of tergites II-V narrowly black, tergites VI+ black, sternite I with a high, laterally compressed, nasute ventral protuberance, ovipositor 1.0-1.3times as long as hind tibia.