Apteroscirtus cristatus Hemp

Hemp, Claudia, 2013, Annotated list of Tettigoniidae (Orthoptera) from the East Usambara Mountains Tanzania and new Tettigoniidae species from East Africa, Zootaxa 3737 (4), pp. 301-350 : 329

Apteroscirtus cristatus Hemp n. sp. ( Fig. 18 , Fig. 19 , Fig. 20 A, C, Fig. 21 A, Fig. 22 A)

http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:180011

Holotype male. Tanzania, West Usambara Mountains, Mazumbai forest reserve, forest floor along path at 1500 m, leg. C. Hemp, depository: ZMNB. 1 female, Mazumbai forest reserve, caught at night at 1550 m, October 2006, depository: ZMNB.

Paratypes. 12 males, 14 females, 7 nymphs, all coll by Jago, Tanzania, West Usambara Mountains, Mazumbai forest reserve, November 1964, June 1967, July 1967, coll N. Jago; 2 males, West Usambara Mountains, Lushoto Arboretum, 1966, leg. Jago. 1 female, West Usambara Mountains, Sakarani, 1500 m, December 1952, leg. Lindemann und Pavlitzki. Depository: all BMNH.

Further paratype material: 1 female, West Usambara Mountains, Mazumbai forest reserve, Kwagoroto, 1800 m, March 2003; 1 male, 1 female nymph, same data as holotype, coll. Hemp. Depository: collection C. Hemp.

Description. General body shape and colour: elongated but stout body, mottled brown and black or dirty greenish ( Fig. 18 , 19 ). Head and antennae.— Antennae more than twice the body length, about 4–5 cm long. Fastigium verticis flat, constricted at height of eyes and widening towards height of antennae ( Fig. 20 A); abruptly forming acute angle to face, meeting fastigium of frons in a shallow horizontal line. Thorax.— Pronotum constricted at first sulcus; disk of pronotum flat and smooth with faint median carina. Lateral lobes of pronotum smooth, brown-black marked bordering disk of pronotum. Disk of meso- and metazona of pronotum almost triangular, with slightly undulating posterior margin of pronotum. Sulcus dividing meso- and metazona deep, running almost to lower margin of pronotal lobes. Tegmina tiny rounded lobes, hardly protruding from posterior margin of pronotum. Legs.— Legs long and slender, base of hind femur stout. Hind femora surpassing apex of body about 1.5 times of their length, hind tibiae as long as femora. Tympana of fore tibiae oval and open on both sides. All femora unarmed. Fore and mid tibiae unarmed except for few spines at posterior outer side. Hind tibiae with double-row of numerous stout spines along dorsal side, and few spines at posterior part on inner sides of hind tibiae. Abdomen.— Abdominal tergites medially with conspicuous keels ( Fig. 18 ), elongating posterior margin of tergites. Lateral on abdomen dark brown to black fascia. Cerci stout and of light colour, slightly curved inwardly ( Fig. 20 C). Subgenital plate typical for Apteroscirtus , elongate and acute forked at its posterior end ( Fig. 20 C). Styli minute little dots.

Female.—Larger than male. No signs of tegmina, thus completely apterous. Hind femora very stout and long but only surpassing body about half of their total length. Ovipositor stout and slightly up-curved at posterior part ( Fig. 21 A). Subgenital plate broad with straight posterior margin ( Fig. 22 A).

Measurements, males (mm) (N = 4). Body length 16–20. Length of pronotum 6.0–6.5. Length of hind femur 24–27.

Measurements, females (mm) (N = 4). Body length 20–27. Length of pronotum 7.0–7.2. Length of hind femur 27–31. Ovipositor length 16–20.

Diagnosis.— A. cristatus n. sp. can be separated easily from other members of Apteroscirtus by the elongated keels on the adominal tergites. The abdomen of A. denudatus is completely smooth, A. ruwenzoricus Rehn has week keels and also A. planidorsatus n. sp. has smooth abdominal tergites. A. inalatus (Karsch) has rounded wing lobes, an unique character among the described species of Apteroscirtus .

Etymology. – lat. cristatus = crest, because of the pronounced abdominal keels medially on the tergites.

Distribution: Tanzania, probably endemic to the West Usambara Mountains.

Ecology & Biology: A. cristatus n. sp. is an inhabitant of leaf litter on the forest floor where it is well camouflaged. It escapes with large jumps when disturbed.

Habitat: Montane forest, recorded from around 1500–1800 m.

Figures

FIGURE 18. Male Apteroscirtus cristatus n. sp., Mazumbai forest reserve in the West Usambara Mountains. Arrows point to keels of abdominal tergites which are conspicuous in this species, but hardly discernible in A. planidorsatus n. sp. from the Uluguru Mountains and thus a good character distinguishing these two Tanzanian species.

FIGURE 19. Male Apteroscirtus cristatus n. sp., habitus, semilateral view; Mazumbai forest reserve.

FIGURE 20. Morphological details of male Apteroscirtus species. A, B. Fastigium verticis, A. cristatus n. sp. (A) and A. planidorsatus n. sp. (B). C, D. Male abdominal apex, A. cristatus (C) and A. planidorsatus (D).

FIGURE 21. Ovipositors of Apteroscirtus species. A. A. cristatus n. sp. B. A. planidorsatus n. sp.

FIGURE 22. Subgenital plates of female Apteroscirtus species. A. A. cristatus n. sp. B. A. planidorsatus n. sp.