Trichomma intervalensis, Onody & Penteado-Dias, 2025

Onody, Helena Carolina & Penteado-Dias, Angélica Maria, 2025, First record of the genus Trichomma Wesmael (Hymenoptera, Ichneumonidae) from Brazil with description of a new species, Zootaxa 5642 (1), pp. 51-58 : 54-57

Trichomma intervalensis sp. nov.

Figs 2–6

Material examined

Holotype: female ( DCBU 172261 ), BRAZIL, São Paulo, Ribeirão Grande, Parque Estadual de Intervales, 24°16’23.6”S 48°25’21.8”W, Armadilha Malaise 05, 840 m, 23.vii.2010, N. W. Perioto e eq. col . Paratypes: 1 female ( DCBU 173666 ), same data as holotype ; 1 male ( DCBU 155118 ), same data as holotype except 20.xii.2010 ; 1 female ( DCBU 3263046 ), Santa Catarina, São Bento do Sul, Armadilha Malaise , 635 m, 06.xi.2002, M. M. Dombeck col. ; 1 female ( DCBU 339934 ), same data except iii.2003 .

Diagnosis: This species is predominantly black, with strongly impressed rugose notauli, a reticulate and laterally carinated scutellum, and hyaline wings.

Description. Female ( Fig. 2–4 ): Fore wing 5.9–7.4 mm.

Head. Head ( Fig. 3A ) mostly slightly matte on face, highly polished on gena and occiput, and finely punctate; vertex, stemmaticum and frons strongly coriaceous, with frons transversely striated; vertical carina absent between antennal sockets; upper tooth of the mandible slightly longer than lower tooth; malar space 0.5× as long as basal width of mandible; clypeus weakly convex, about 1.6–1.8× as wide as high, with a distinct median apical tooth on its apical margin; eyes convergent ventrally bearing long pubescence on their surface; anterior tentorial pit touches the inner margin of eye; posterior ocellus separated from the eye margin by 2.0–2.5× its diameter; lateral ocelli 2.0× their diameter from the eye, 1.0–1.3× apart from each other, and 0.3–0.5× from the occipital carina; occipital carina strongly projected ventrally, reaching base of the mandible; antenna with 40–42 flagellomeres, the first flagellomere apically 1.1× its basal width and 1.8–2.0× the height of second flagellomere.

Mesosoma. Pronotum smooth and polished, striate basally; epomia present but does not reach the base of the mesoscutum; mesoscutum ( Fig. 3B ) matte, punctate and with impressed rugose notauli; scutellum reticulate with lateral carina; mesopleuron more or less smooth and polished, transversely slightly punctate and dorsally striate; epicnemial carina extends toward but does not touch the mid-posterior margin of the pronotum; sternaulus weak; posterior transverse carina of the mesosternum present centrally and irregular laterally; propodeum and metapleuron coarsely reticulate; apex of the propodeum projecting 0.5× the length of hind coxa; fore wing with a thin pterostigma vein; vein 1cu-a is postfurcal to M& RS; vein 2rs-m 0.8× the 1M vein; vein 2cu-a 5× the 2CU vein; vein 2m-cu with one bulla; hind wing with 6–8 hamuli; nervellus not intercepted; vein first abscissa of RS same length of rs-m; distal abscissa of RS absent, sometimes spectral.

Metasoma. Mostly matte/coriaceous, except for the base of the first metasomal segment, which is smooth and polished; length of first metasomal segment 0.7× the length of tergite II; length of second metasomal segment 1.6× the length of tergite III; thyridium absent; ovipositor straight, 1.4–1.6× the length of hind femur.

Color. Silver pilosity. Head white yellow, mandible teeth, frons, stemmaticum, vertex and occiput areas black; scape white yellow and black, pedicel and flagellomeres entirely black; mesosoma black, but tegula, subtegular ridge and pronotum dorsally are yellow; fore and mid legs yellow, with coxae, trochanter and trochantellus white yellow, tarsi distally infuscate; hind leg black, except for the tibial spurs, trochantellus ventrally and tibia subapically white yellow; wings hyaline.

Male ( Fig. 5 ): Similar in structure and color to the female.

Biology. Unknown.

Distribution. This species is known to occur only in Brazil ( Fig. 6 ).

Etymology. The species name derives from the type locality, Parque Estadual Intervales.

Comments. This species differs from the other two Neotropical species by having a predominantly black body (as opposed to mainly rufous in T. politum and a head that is yellow, mesosoma black and metasoma reddish in T. batistai ), mesopleuron more or less smooth and polished, transversely slightly punctate and striate dorsally (it is entirely smooth or polished in T. batistai ), notauli strongly impressed (faint in T. politum ), frons rugose/reticulate (smooth with a few weak transverse rugae in T. batistai ), scutellum reticulate with lateral carinae (polished and impunctate in T. politum ), wings hyaline (strongly infuscate in T. politum ) and a relatively long antenna with 40–42 flagellomeres (up to 35 in T. politum ).

Figures

FIGURE 2. Trichomma intervalensis sp. nov. A: long hairs on the surface of the eyes; B: 2 clypeus with a distinct median apical tooth (white arrow); C: fore coxa without a ventral 3 carina. Scale bars: A = 400 μm; B = 200 μm; C = 300 μm.

FIGURE 3. Trichomma intervalensis sp nov holotype. A: frontal view of the head; B: 2 dorsal view of head and mesoscutum. Scale bars = 0.5 mm.

FIGURE 4. Trichomma intervalensis sp. nov. habitus, female holotype. Scale bar = 3 mm.

FIGURE 5. Trichomma intervalensis sp. nov. habitus, male paratype. Scale bar = 2 mm.

FIGURE 6. Distribution map of Trichomma intervalensis sp. nov.