Acrotaphus Townes, 1960

Khalaim, Andrey I., Ruíz-Cancino, Enrique & Coronado-Blanco, Juana María, 2024, Darwin wasps of the subfamily Pimplinae (Hymenoptera: Ichneumonidae) of Mexico: Polysphincta genus-group, Zootaxa 5458 (2), pp. 151-196 : 153-154

Genus Acrotaphus Townes, 1960

Acrotaphus Townes in Townes & Townes 1960: 256. Type species: Epimecis wiltii Cresson, 1870 , by original designation.

Synonym:

Epimecis Brullé, 1846 (name preoccupied by Huebner, 1825).

References. Cresson 1865: 32 [ Epimecis ; 4 species (all described as new) in Cuba]. Townes & Townes 1966: 18 [catalogue; 7 species in Neotropical region; 2 species in Mexico]. Townes 1969: 106 [diagnosis]. Carlson 1979: 337 [catalogue; 1 species in North America]. Gauld 1991: 322 [description; review of 5 species from Costa Rica (2 described as new); key]. Gauld et al. 1998: 119 [5 species in Costa Rica; key]. Gauld et al. 2002: 44 [4 species in El Salvador; key]. Brambila & Porter 2005 [3 species in USA; key; biology]. Higa & Penteado-Dias 2020: 381–382 [1 new species from Brazil; key]. Pádua & Kloss 2020 [1 new species from Brazil; host]. Pádua et al. 2020a [review of 26 New World species (15 described as new); key].

Acrotaphus is a New World genus with 27 species. South American fauna of the genus was recently described by Pádua et al. ( Pádua et al. 2020a; Pádua & Kloss 2020). Three species were described from Cuba by Cresson (1865), of these one was subsequently recorded from Florida ( Brambila & Porter 2005) . Thus, three species of Acrotaphus occur in North America, eight in Central America, three in Cuba, with the remaining species restricted to South America. Four species are known to occur in Mexico.

Species of Acrotaphus are koinobiont ectoparasitoids on active spiders. The parasitoid larvae were recorded to induce their host spiders to build modified webs before they kill them and pupate ( Eberhard 2013). Many species are nocturnally active and often attracted at light.

Palacio (1999) recorded Acrotaphus specimens inside empty cell in the nest of the sphecid wasp Trigonopsis violascens (Dalla Torre) ( Sphecidae ), in cells with paralyzed, live spiders, and assumed that it was accidental event, and the sphecid wasp had paralyzed and collected spiders that had been already parasitized by the ichneumonid.

Acrotaphus fuscipennis is included to the key because it was recorded from Cuba and southeastern USA, and therefore has the potential to be found in Mexico.

Key to species of Acrotaphus occurring in Mexico

1. Fore wing strongly darkened, pterostigma blackish. Mesosoma and metasoma bright red. USA (Florida) and Cuba; not recorded from Mexico..................................................................... A. fuscipennis (Cresson)

– Fore wing yellow with black transverse bands, pterostigma yellow ( Figs 1, 4 ). Mesosoma and metasoma generally orange ( Figs 1, 3 )............................................................................................... 2

2. Hind femur orange or yellowish brown.................................................... 4. A. wiltii (Cresson)

– Hind femur dark reddish brown to black ( Fig. 1 )............................................................ 3

3. Female............................................................................................. 4

– Male............................................................................................... 6

4. Head, in dorsal view, with ocelli moderately large, lateral ocellus separated from margin of eye by more than 0.2× its own maximum diameter. Gena narrowed behind eye, but not concave. Metasoma moderately slender, tergite 3 less than 1.2× as long as posteriorly broad. [Mesosoma entirely orange. Hind leg entirely black. Metasoma predominantly orange, tergites 5 and following black. Scutellum, in profile, almost pyramidal. Hind wing with nervellus intercepted above middle.]........................................................................................ 2. A. mexicanus (Cameron)

– Head, in dorsal view, with ocelli very large, the lateral one virtually touching margin of eye ( Fig. 2 ). Gena concave behind eye ( Fig. 2 ). Metasoma very slender, tergite 3 more than 1.3× as long as posteriorly broad.............................. 5

5. Epicnemial carina only present ventrally, not extending onto lateral face of mesopleuron. Hind leg dark reddish brown to black, with only base of coxa narrowly orange basally. Metasoma orange, with posterior margins of tergites 2–4 narrowly black, and tergites 5 and following blackish.................................................. 1. A. latifasciatus (Cameron)

– Epicnemial carina extending laterally onto mesopleuron, its upper end reaching level of lower corner of pronotum ( Fig. 3 , arrow). Hind leg with coxa, trochanters and basal 0.7 of tibia orange, the rest blackish ( Fig. 1 ). Metasoma with tergites 1–5 entirely orange, tergites 6 and following blackish ( Fig. 1 )................................... 3. A. tibialis (Cameron)

6. Epicnemial carina present only ventrally, not extending onto lateral faces of mesopleuron. [Head with ocelli very large, the lateral one more or less touching margin of eye. Metasoma orange, with posterior margins of tergites 2–4 narrowly black, and tergites 5 and following blackish or dark reddish brown (small specimens sometimes with tergite 5 also orange with black posterior margin).]............................................................. 1. A. latifasciatus (Cameron)

– Epicnemial carina present ventrally, extending onto lateral faces of mesopleuron and reaching level of lower corner of pronotum........................................................................................... 7

7. Hind leg entirely black.......................................................... 2. A. mexicanus (Cameron)

– Hind leg orange with distal 0.3–0.4 of tibia and entire tarsus blackish. [Metasoma with tergites 1–5 entirely orange, 6 and following blackish.]................................................................. 3. A. tibialis (Cameron)

Figures

FIGURES 1–4. Acrotaphus tibialis, ♀ (Tamaulipas): 1—habitus, lateral; 2—head, dorsal; 3—mesosoma, lateral; 4—fore wing.