Scambus

Gómez, Isrrael C. & Yabar-Landa, Erick, 2015, Description of the first species of Scambus Hartig (Hymenoptera, Ichneumonidae) from Peru, with a key to the Neotropical species, Zootaxa 3956 (3), pp. 437-443 : 438-439

Key to the Neotropical species of Scambus

The following key works best for females. For this reason, the identification of male specimens should always be confirmed by comparing them with female specimens and descriptions. The measurement of ovipositor sheath is equivalent to the exposed length of the ovipositor (posterior to the apex of the metasoma). Further variation (i.e. in ovipositor length) may occur in Scambus since most of the Neotropical described species are currently represented by few specimens.

1. Ovipositor sheath very long approximately equal to body length, [mesosoma and metasoma entirely red, ovipositor sheath about 3.6 × as long as hind tibia]..................................................... Scambus nigriceps Brullé

- Ovipositor sheath shorter than body length................................................................. 2.

2. Tergite I very short about 0.7 × as long as posteriorly broad, [wings very weakly infumate, red insects with posterior part of scutellum, mesosternum and tergites apically black, ovipositor sheath about 1.6 × as long as hind tibia]...................................................................................................... S. holmbergi Brèthes.

- Tergite I 0.9–1.4 × as long as posteriorly broad............................................................. 3.

3. Hind wing with abcissa of Cu 1 absent or extremely indistinct, legs white, ovipositor sheath between 2.1–2.3 × as long as hind tibia................................................................................. S. espinozai Gauld.

- Hind wing with abcissa of Cu 1 clearly visible...............................................................4.

4. Mesosoma and metasoma entirely black....................................................................5.

- Mesosoma and metasoma not as above.................................................................... 8.

5. Hind coxa orange.................................................................................... 6.

- Hind coxa black or whitish............................................................................. 7.

6. Ovipositor relatively thick (about twice the thickness of first flagellar segment), ovipositor sheath between 1.6-1.8 × as long as hind tibia, tergite II smooth without punctures.................................................. S. emeritai Gauld

- Ovipositor relatively slender (about one time the thickness of first flagellar segment), ovipositor sheath between 2.6-2.8 × as long as hind tibia, tergite II with sparse punctures centrally.......................................... S. erasi Gauld

7. Hind coxa black ( Fig. 2 a), tergite I about 1.0 × as long as posteriorly broad, ovipositor about 2.8 × as long as hind tibia....................................................................................... S. incanus Gómez sp. n.

- Hind coxa whitish, tergite I about 1.4 × as long as posteriorly broad, ovipositor about 2.1 × as long as hind tibia................................................................................................. S. zunigai Khalaim

8. Ovipositor sheath between 3.0-3.3 × as long as hind tibia..................................................... 9.

- Ovipositor sheath about 2.7 or less × as long as hind tibia.................................................... 10.

9. Metasomal tergites II and III punctate centrally, tergite I about 1.1 × as long as posteriorly broad, hind legs pale orange, propleuron and scutellum red, ovipositor sheath about 3.1 × as long as hind tibia.................... S. flavipes Cameron

- Metasomal tergites II and III punctate over most of the surface, tergite I about 0.9 × as long as posteriorly broad, hind legs pale yellow, propleuron and scutellum black, ovipositor as long as abdomen............................. S. albipes Cresson

10. Tergite II short and stout about 0.6 × as long as posteriorly broad, ovipositor sheath rather short about 1.6 × as long as hind tibia, coxa and femur orange............................................................... S. albitibia Morley

- Tergite II about 0.7 or more × as long as posteriorly broad, ovipositor sheath 2.0 or more × as long as hind tibia......... 11.

11. Hind coxa and mesoscutum entirely black ( Fig. 1 a), antenna with 21 flagellomeres, tergite III about 0.65 × as long as posteri- orly broad..................................................................... S. amazonicus Gómez sp. n.

- Hind coxa whitish or orange, mesoscutum brown or reddish.................................................. 12.

12. Hind coxa orange, metasoma entirely black, antenna with about 26 flagellomeres, [lower face very finely punctate].................................................................................................. S. scotti Gauld

- Hind coxa whitish, metasoma brown, antenna with about 24 or fewer flagellomeres............................... 13.

13. Ovipositor sheath about 2.6-2.7 × as long as hind tibia, tergite II smooth and polished with isolated punctures.................................................................................................... S. yalileae Gauld

- Ovipositor sheath between 2.0-2.2 × as long as hind tibia, tergite II smooth and polished strongly punctate............. 14.

14. Mandible with upper tooth wider than lower tooth, pronotum with white margins, propodeum red with black stripe (from ante- rior till posterior margin).................................................................. S. monroi Gauld

- Mandible subequally bidentate, pronotum brownish, propodeum uniformly brown...................... S. basseyi Gauld

Figures

FIGURE 1. Scambus amazonicus sp. n. a) habitus, b) face, c) mesosoma, and d) metasoma.

FIGURE 2. Scambus incanus sp. n. a) habitus, b) face, c) mesosoma, and d) metasoma.