A new species of Acrotaphus Townes (Hymenoptera: Ichneumonidae: Pimplinae) from the Brazilian Amazon, with notes on its host spider behavioral modification Author Pádua, Diego G. Programa de Pós-Graduação em Entomologia, Instituto Nacional de Pesquisas da Amazônia-INPA, Brazil. paduadg @ gmail. com; https: // orcid. org / 0000 - 0001 - 5061 - 2978 Author Kloss, Thiago G. Departamento de Ciências Biológicas, Universidade do Estado de Minas Gerais-UEMG, Campus Ubá, Brazil. thiagogkloss @ gmail. com; https: // orcid. org / 0000 - 0003 - 0958 - 1748 text Zootaxa 2020 2020-07-09 4810 1 161 168 journal article 21529 10.11646/zootaxa.4810.1.10 578272bd-a696-4065-b739-dbf6966706f8 1175-5326 3937023 6438F1BE-3815-4645-892E-0CA7CA3809B3 Acrotaphus wagnerianae Pádua , sp. n. ( Figs 1 A–J) Diagnosis. This species can be distinguished from other Acrotaphus species by the combination of the following character states: 1) margin of the gena behind the eyes weakly concave in dorsal view; 2) margin of the gena 0.6–0.7 height of eye in dorsal view; 3) posterior ocelli separated from eyes by approx. 0.7× its own maximum diameter in dorsal view; 4) mesosoma orange, with propleuron, pronotum, mesoscutum and mesopleuron, except posterior margin brownish (mesopleuron entirely orange in males); 5) hind leg orange, with distal 0.4 of femur, tibia and tarsus black (orange with distal 0.8 of femur, tibia and tarsus black in males); 6) female with tarsal claw with basal lobe longitudinally, with claw apex overtaking the posterior margin of lobe; 7) ovipositor robust, 1.3× as long as hind tibia. Description. Female. Body approx. 17.0 mm. Head. Lower face approx. 1.1× as broad as high, rather flat, laterally with scattered punctures which bear long conspicuous bristles; head in dorsal view, with margin of the gena weakly concave behind the eyes; margin of the gena 0.7× height of eye in dorsal view; posterior ocelli separated from eyes by 0.7× its own maximum diameter in dorsal view. Mesosoma. Pronotum moderately long, smooth and polished, with distance from tegula to head is greater than 0.65× distance from tegula to hind margin of propodeum; mesoscutum smooth and polished, with notaulus weakly marked; scutellum triangular in dorsal view; mesopleuron polished, with fine bristles anteriorly and ventrally; epicnemial carina present ventrally, extending until reaching the level of the lower corner of the pronotum laterally; metapleuron polished, with sparse, fine bristles evenly spaced and with a strongly longitudinal groove in lower part, below spiracle; propodeum smooth dorsally, laterally with scattered fine bristles. Fore wing approx. 14.0 mm; cu-a opposite to the base of Rs&M ; 2 rs-m approx. 0.7× as long as abscissa of M between 2 rs-m and 2 m-cu ; hind wing with abscissa of Cu 1 between M and cu-a approx. 0.9× length of cu-a . Tarsal claw with basal lobe longitudinally, with claw apex overtaking the posterior margin of lobe. Metasoma. Tergite I 1.5× as long as posteriorly broad; tergite II 1.2× as long as posteriorly broad; tergite III approx. 1.1× as long as posteriorly broad; tergites IV–V 0.9× as long as posteriorly broad; ovipositor robust, 1.3× as long as hind tibia; lower valve with slightly swelling in the base and middle region. Colour. Head black, except clypeus brownish; mouthparts orange, except apex of mandible black; antenna brownish dark. Mesosoma orange, with propleuron, pronotum, mesoscutum and mesopleuron, except posterior margin brownish. Metasoma orange with tergites V+ black. Anterior and middle leg orange, hind leg orange, with distal 0.4 of femur, tibia and tarsus black. Wings yellowish; the fore wing with apex distal to 2 rs-m black, and with a black median band extending backwards from anterior margin, just proximal to the pterostigma, right through the 1 st subdiscal cell; pterostigma yellowish. Ovipositor brownish, with its base and apex pallid and sheath dark brown. Male. ( Figs 1 E–J). Similar to female in structure and coloration, except clypeus black; mesopleuron entirely orange and hind leg orange with distal 0.8 of femur, tibia and tarsus black; lower face 1.0× as broad as high; margin of the gena 0.7–0.75× height of eye in dorsal view; posterior ocelli separated from eyes by 0.6–0.75× its own maximum diameter in dorsal view; sternite IX ( Fig. 1H ) longer than high, with lateral and anterior margins strongly sclerosed, lateral margin flat and posterior margin light concave, with few bristles widely spaced posteriorly. Genital capsule ( Figs 1 I–J): Paramere angled apically, slightly narrower than the parameral lamina, with bristles except in posterior margin; volsellar lamina with bristles antero-apically, spaced in anterior margin and with a set of four bristles in anterolateral region, just below the base of the digitus; cuspis robust with about four queued teeth in the middle part until apex and with three few bristles spaced in apical region; digitus with teeth in apex, rounded distally and angulated ventrally, with the margins of the apical region narrower than base; aedeagus with few teeth in apex and its apex slightly curved downward in lateral view. Cocoon. Ovoid, white color, semi-transparent, without a caudal orifice, 15.4 mm long by 8.1 mm wide and consists of loose silk loops. The posterior end of the cocoon does not have a clear opening, in which the meconium was inside, in the final part of cocoon. FIGURE 1. Acrotaphus wagnerianae sp. n. : ( A ) habitus ♀ (holotype), scale bar: 2 mm; ( B) face, frontal view ♀ (holotype), scale bar: 0.5 mm; ( C) head, dorsal view ♀ (holotype), scale bar: 0.2 mm; ( D) tarsal claw ♀ (holotype), scale bar: 0.2 mm; ( E) habitus ♂ (paratype), scale bar: 2 mm; ( F) head, dorsal view ♂ (paratype), scale bar: 0.5 mm; ( G) cocoon ♂ (paratype), scale bar: 2 mm; ( H) sternite IX ♂ (paratype), scale bar: 0.2 mm; ( I) genital capsule, lateral view ♂ (paratype), scale bar: 0.2 mm; ( J) genital capsule, ventral view ♂ (paratype), scale bar: 0.2 mm. Type material: Holotype : ♀ , BRAZIL , Amazonas , Coari , Rio Urucu , Angelim , 05°03’33’’S / 65°14’48’’W , 23.xi–02.xii.1992 , Mercury light ( P.F. Bührnheim & N.O. Aguiar leg.), UFAM . Paratypes : Amazonas , Manaus , Reserva Ducke , emerged of Wagneriana sp., 15.x.2018 [pupa collected] ( T . G. Kloss ; E. Kloss & D.G. Pádua leg.), ♂ , INPA ; idem, but 14.x.1995 , FOG [= Fogging ] in Corythophora alta (without the collector name), ♂ [with the last metasomal segments extracted], INPA . Distribution. Brazil ( Amazonas state ). Etymology. Named after host. Biological note. Parasitoid of Wagneriana sp. ( Araneidae ). Comments. Acrotaphus wagnerianae sp. n. closely resembles A. franklini Gauld and A. homeofranklini Pádua by having parts of the mesosoma black, but differs from both by having tarsal claw with lobe elongated longitudinally, apex of claw overtaking the posterior margin of lobe ( Fig. 1D ), margin of the gena weakly concave behind the eyes ( Fig. 1C ), hind leg orange, with distal 0.4 of femur, tibia and tarsus black ( Fig. 1A ), or males with hind leg orange with distal 0.8 of femur, tibia and tarsus black ( Fig. 1E ). In comparison, gena flat and tarsal claw with quadrangular lobe in both A. franklini and A. homeofranklini , and hind leg entirely black or black with parts of tibia brownish in A. franklini , and hind leg entirely black or with proximal half of the femur brownish in A. homeofranklini . Web modification. Although we did not observe a normal web in the field, it is known that normal webs of Wagneriana spiders are characterized by a vertical two-dimensional orb web, with several radii and sticky spirals. In addition, there is no retreat or barrier tangle in these webs ( Levi 1991 ; Alayón 2011 ). However, the cocoon web built by the parasitized individual of Wagneriana sp. had no sticky spirals and contained a barrier tangle on both sides of the hub, resulting in an irregular tangle of non-sticky threads ( Figs 2 A–C). We also observed that the web had a vertical hub ( Fig. 2B ), which does not present hub spirals, although it was possible to identify some radii converging to the web hub. Lines of cocoon webs were attached to the vegetation at several points ( Fig. 2A ).