Scambus Hartig, 1838

Khalaim, Andrey I. & Ruíz-Cancino, Enrique, 2022, Darwin wasps of the subfamily Pimplinae (Hymenoptera: Ichneumonidae) of Mexico: Ephialtes genus-group, Zootaxa 5169 (3), pp. 201-251 : 227-230

Genus Scambus Hartig, 1838

Scambus Hartig 1838: 267 .

Type species: Scambus sagax Hartig, 1838 , by subsequent designation ( Viereck 1914: 131).

Synonyms:

Ateleophadnus Cameron, 1905 .

Epiurus Förster, 1869 (name preoccupied by Rafinesque, 1815).

Erythroscambus Walley, 1960.

Lissoscambus Walley, 1960.

Pseudopoemenia Kiss, 1924 .

Troctocerus Woldstedt, 1876 .

Tromera Förster, 1869 .

References. Townes & Townes 1951: 185 [catalogue; 13 species in America north of Mexico]. Townes & Townes 1960: 15 [revision of 5 subgenera and 26 species (2 subgenera and 13 species described as new) from America north of Mexico; key]. Townes & Townes 1966: 9 [catalogue; 3 subgenera and 9 species in Neotropical region; 7 species in Mexico]. Townes 1969: 69 [description; distribution]. Carlson 1979: 322 [catalogue; 5 subgenera and 27 species in America north of Mexico]. Gauld 1991: 167 [description; review of 6 species (all described as new) from Costa Rica; key]. Gauld et al. 1998: 17 [6 species in Costa Rica; key]. Ruíz-Cancino et al. 2002: 645 [checklist; 10 species in Mexico]. Gauld et al. 2002: 33 [review of 4 species from El Salvador (1 described as new); key]. Khalaim 2010: 209 [1 new species from Costa Rica]. Gómez & Yabar-Landa 2015 [2 new species from Peru; key to 15 Neotropical species].

Scambus is a large predominantly Holarctic genus comprising about 90 distinct species, and taxonomical status of about 50 species is uncertain ( Yu et al. 2016). In South America the genus appears to be uncommon being represented by only four species ( Gómez & Yabar-Landa 2015). Eight species are known from Central America and about ten species were reported from Mexico ( Ruíz-Cancino et al. 2002).

Townes ( Townes & Townes 1960: 25) mentioned two undescribed Mexican species similar to S. arizonensis . Scambus coxatus (Smith) , mentioned by Townes in the catalogue of Neotropical Ichneumonidae ( Townes & Townes 1966: 10) actually belongs to Calliephialtes (see Gauld 1991: 169, 185).

Three Mexican species, S. flavipes (Cameron) , S. mexicanus (Cameron) and S. montezuma (Cameron) , are known to us only from their brief descriptions, and therefore these species are not included to the key. Type of S. mexicanus is lost, the taxonomic status of this species is uncertain, and therefore it is not included to the list of Mexican species. We were unable to associate six morphospecies to known Mexican species and therefore marked them by letters A to F. When types of the three Cameron species deposited in the BMNH collection are examined, these morphospecies will be associated with our morphospecies, or described as new.

The abundant Holarctic species S. vesicarius (Ratzeburg) was reported from Mexico in the checklist by RuízCancino et al. (2002). This record was based on a single male from the State of Durango which was preliminarily identified by D.R. Kasparyan as S. vesicarius . However, the presence of this species in Mexico requires confirmation based on the new material, especially on the collecting of females.

Types of six Costa Rican species, S. emeritae Gauld , S. erasi Gauld , S. espinozai Gauld , S. basseyi Gauld , S. scotti Gauld and S. yalileae , deposited in the INBio collection, have been examined by the senior author. Scambus bassey was found to be conspecific with S. crassicauda (Cresson) (syn. nov.), and S. espinozai is probably a junior synonym of S. albipes (Cresson) .

One species, S. monroi Gauld et al. , was described from El Salvador ( Gauld et al. 2002); according to its original describtion, this species is similar to S. albipes and characterized by white hind coxa, ovipositor 2.4–2.5× as long as hind tibia, with apical denticles on the lower valve oblique (about 45° from horizontal), and propodeum with a broad longitudinal black mark extending from its base to apex.

Thus, sixteen species of Scambus are recognized here in the fauna of Mexico, including six morphospecies, and excepting S. mexicanus and S. vesicarius .

Species of Scambus are idiobiont ectoparasitoids of larvae of various holometabolous insects (mainly Lepidoptera ) concealed in plant tissues; also known as facultative hyperparasitoids ( Gauld 1991).

Key to species of Scambus occurring in Mexico

1. Mesosoma entirely black, excepting narrowly whitish posterior corner or dorsal margin of pronotum ( Figs 55 , 59 ). Mesoscutum more or less densely pubescent. Submetapleural carina present or absent......................................... 2

- Mesosoma red, or red and black, at least mesopleuron extensively red marked ( Figs 42 , 51 , 65 , 70 , 81 , 84 ). Mesoscutum polished, with sparse setae. Submetapleural carina absent or incomplete......................................... 5

2. Hind coxa unusually long, almost twice as long as broad ( Fig. 61 ). Tergites 3 and 4 slightly transverse. Ovipositor thin and straight, as least as long as body ( Fig. 60 ). [Tergites 2–8 dark reddish brown with black transverse posterior bands; black bands on tergites 5–8 more or less reduced medially ( Fig. 60 ).]................................... 9. S. longicoxa sp. nov.

- Hind coxa not unusually slender, about 1.5× as long as broad. Tergites 3 and 4 strongly transverse. Ovipositor slender or robust, distinctly shorter than body............................................................................. 3

3. Submetapleural carina absent ( Fig. 56 ). Fore coxa white ( Fig. 55 ). First tergite with lateromedian carinae short, reaching 0.5 of the tergite. Tergites 2–4 with scattered sharp punctures, smooth and shining between punctures ( Fig. 57 ). Ovipositor sheath 1.5–1.6× as long as hind tibia, or 0.7–0.8× as long as metasoma ( Fig. 54 )........................ 6. S. emeritae Gauld

- Submetapleural carina complete. Fore coxa orange-brown. First tergite with lateromedian carinae longer, reaching 0.6–0.7 of the tergite. Tergites 2–4 densely punctate. Ovipositor sheath more than twice as long as hind tibia ( Figs 38, 40 ).......... 4

4. Notaulus deeply impressed, long, reaching centre of mesoscutum. Pterostigma pale yellow. Legs entirely reddish orange ( Fig. 59 ).......................................................................... 8. S. irapuatoensis sp. nov.

- Notaulus moderately strong, not reaching centre of mesoscutum. Pterostigma brown. Fore trochanter and trochantellus whitish, hind tibia with conspicuous white stripe on upper side, hind tarsomeres white basally and blackish apically............................................................................................ 3. S. aplopappi (Ashmead)

5(1). Mesepimeron and propodeum black, metapleuron red or black ( Figs 65 , 70 , 76 ). Hind leg with coxa and femur reddish orange............................................................................................. 6

- Mesepimerom white or red, propodeum and metapleuron usually partly or entirely red ( Figs 42 , 51 ). Hind leg with coxa and femur orange or white................................................................................. 8

6. Ovipositor sheath 1.3–1.5× as long as metasoma ( Fig. 63 ). Malar space 0.4× as long as basal mandibular width in female and 0.3–04× in male. Mesopleuron ventrally more or less blackish (especially in males), sometimes entire ventral and lateroventral parts of mesopleuron black. Tergites 3–5 irregularly punctate basally in female ( Fig. 66 ) and impunctate in male (more or less corrugate). Pterostigma pale yellow ( Fig. 63 ). [Male with parameres apically broadly rounded.]........ 12. Scambus sp. B

- Ovipositor sheath at most 1.2× as long as metasoma. Malar space 0.2–0.3× as long as basal mandibular width. Mesopleuron ventrally red, sometimes only mesosternal suture blackish. Tergites 3–5 distinctly punctate basally (or entirely) in female ( Fig. 74 ), either punctate or impunctate in male. Pterostigma pale brown to brown ( Figs 68, 72 )........................... 7

7. Metapleuron red ( Fig. 70 ). Mesoscutum red but usually with central and posterior blackish marks ( Fig. 69 )................................................................................................... 13. Scambus sp. C

- Metapleuron black ( Fig. 76 ). Mesoscutum immaculately red ( Fig. 77 )............................ 14. Scambus sp. D

8. Ovipositor strongly compressed, 2.0–2.5× as high as wide centrally, with ventral subapical teeth mostly subvertical, most proximal tooth subtending an angle of about 45º to axis of shaft ( Figs 49 , 82 ); sheath 0.5–0.8× as long as metasoma ( Figs 47 , 52 , 80 )............................................................................................. 9

- Ovipositor weakly compressed, about 1.5× as high as wide centrally, with ventral subapical teeth mostly oblique, most proximal tooth subtending an angle of about 30º to axis of shaft (as in Figs 58 , 67 , 79 ); sheath 0.6–1.2× as long as metasoma...... 11

9. Hind coxa and usually femur white ( Fig. 52 ). Mesopleuron usually immaculately orange, without black markings; mesepimeron yellow ( Fig. 52 ). Propodeum red, sometimes with median longitudinal blackish stripe.......... 5. S. crassicauda Cresson

- Hind coxa and femur orange (femur apically narrowly whitish), distinctly differing from whitish hind trochanter, trochantellus and tibia (tibia with fuscous marks) ( Figs 47 , 80 ). Mesopleuron often conspicuously black-marked. Propodeum black or extensively black marked............................................................................. 10

10. Fore and mid coxae white ( Fig. 51 ). Pronotum tricoloured—black ventrally, orange centrally and white dorsally ( Fig. 51 ). Scape and pedicel of antenna usually white ventrally. Malar space 0.3–0.4× as long as basal mandibular width. Submetapleural carina usually completely absent. [Ovipositor sheath 1.6–1.8× as long as hind tibia ( Fig. 47 ). Male paramers apically long, pointed and usually decurved.]....................................................... 4. S. arizonensis Walley

- Fore and mid coxae orange ( Fig. 80 ). Pronotum black with white dorsal stripe ( Fig. 81 ). Scape and pedicel of antenna black. Malar space 0.4–0.6× as long as basal mandibular width. Submetapleural carina present in anterior 0.2–0.3 of metapleuron as distinct tubercle. [Ovipositor sheath 1.55–1.9× as long as hind tibia. Propodeum black.].............. 15. Scambus sp. E

11. Hind coxa and femur white; hind femur in female usually with fuscous stripes on inner and outer sides ( Fig. 43 ). Hind wing with distal abscissa of Cu 1 absent or extremely indistinct ( Fig. 44 ). [Female with tergite 6 apically strongly reduced ( Fig. 45 ). Ovipositor sheath about as long as metasoma ( Fig. 41 ). Mesopleuron orange, without black markings ( Fig. 42 ). Propodeum blackish anteriorly. Male parameres apically narrow and ventrally concave, metasoma dark reddish brown to black.].......................................................................................... 1. S. albipes Cresson

- Hind coxa and sometimes femur orange ( Figs 46 , 83 ). Hind wing with distal abscissa of Cu 1 distinct ( Fig. 84 ).......... 12

12. Mesosoma reddish orange, only propleuron and pronotum with blackish and white marks, and mesepimeron whitish ( Fig. 46 ). Tergite 5 of metasoma not of weakly reduced apically. Ovipositor sheath 0.6–0.8× as long as metasoma ( Fig. 46 )........................................................................................... 2. S. albitibia (Morley)

- Mesopleuron with dorsoposterior black mark ( Fig. 84 ); propodeum extensively black marked to entirely black ( Fig. 84 ). Tergite 5 of metasoma with hind smooth black margin sometimes entirely reduced. Ovipositor sheath 0.9–1.2× as long as metasoma ( Fig. 83 )........................................................................................... 13

13. Tergite 5 of metasoma with hind smooth black margin entirely reduced. Propodeum red with black markings.................................................................................................. 11. Scambus sp. A

- Tergite 5 of metasoma with hind smooth black margin not or weakly reduced ( Fig. 85 ). Propodeum black, sometimes with lateral sides reddish ( Fig. 84 )............................................................. 16. Scambus sp. F

Figures

FIGURE 74. Scambus sp. C, ♀ (Tamaulipas): 74—metasomal tergites 2–4, dorsal.

FIGURES 54–58. Scambus emeritae, ♀ (Tamaulipas): 54—habitus, lateral; 55—head and mesosoma, lateral; 56—propodeum, lateral; 57—metasomal tergites 2–4, dorso-lateral; 58—apex of ovipositor, lateral.

FIGURES 59–62. Scambus irapuatoensis sp. nov., paratype, ♀: 59—head, mesosoma and base of metasoma, lateral. Scambus longicoxa sp. nov., holotype, ♀: 60—habitus (without wing apices), lateral; 61—hind coxa, lateral; 62—apex of ovipositor, lateral.

FIGURES 41–45. Scambus albipes, ♀ (41—Tamaulipas, 42–45—Jalisco): 41—habitus, lateral; 42—head, mesosoma and base of metasoma, lateral; 43—fore and mid legs, lateral; 44—portion of hind wing with nervellus; 45—metasoma, dorso-lateral.

FIGURES 50–53. Scambus arizonensis, ♀ (Oaxaca): 50—mesoscutum, dorso-lateral; 51—mesosoma and base of metasoma, lateral. Scambus crassicauda, ♀ (Jalisco): 52—habitus, lateral; 53—apex of metasoma, dorso-lateral.

FIGURES 63–67. Scambus sp. B, ♀ (Tamaulipas): 63—habitus, lateral; 64—head, mesosoma and base of metasoma, lateral; 65—mesoscutum, dorso-lateral; 66—metasomal tergites 2–4, dorso-lateral; 67—apex of ovipositor, lateral.

FIGURES 68–73. Scambus sp. C, ♀ (68–71) and ♂ (72, 73) (Tamaulipas): 68, 72—habitus, lateral; 69—mesoscutum and scutellum, dorsal; 70—mesosoma and base of metasoma, lateral; 71—apex of ovipositor, lateral; 72—apex of metasoma with paramers, lateral.

FIGURES 80–82. Scambus sp. E, ♀ (Tamaulipas): 80—habitus, lateral; 81—mesosoma and base of metasoma, lateral; 82— apex of ovipositor, lateral.

FIGURES 83–85. Scambus sp. F, ♀ (Hidalgo): 83—habitus (without antennae and wings), lateral; 84—mesosoma and base of metasoma, lateral; 85—posterior part of metasoma, dorsal.

FIGURES 37–40. Habitus, lateral, ♀: 37—Acropimpla tequila sp. nov. (holotype); 38—Scambus aplopappi; 39—S. longicoxa sp. nov. (paratype); 40—S. irapuatoensis sp. nov. (paratype).

FIGURES 75–79. Scambus sp. D, ♀ (Tamaulipas): 75—habitus, lateral; 76—mesosoma and base of metasoma, lateral; 77— head and mesosoma, dorsal; 78—metasomal tergites 3–5, dorsal; 79—apex of ovipositor, lateral.

FIGURES 46–49. Scambus albitibia, ♀ (Jalisco): 46—habitus, lateral. Scambus arizonensis, ♀ (Oaxaca): 47—habitus, lateral; 48—head, front; 49—apex of ovipositor, lateral.