Acauloplax exigua Karsch, 1891

Naskrecki, Piotr & Guta, Ricardo, 2019, Katydids (Orthoptera: Tettigoniidae) of Gorongosa National Park and Central Mozambique, Zootaxa 4682 (1), pp. 1-119 : 54

Acauloplax exigua Karsch, 1891

http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:7406

( Figs. 5C , 23 A–D, 57A–C)

Diagnostic remarks. A medium-sized, pale green katydid that can be identified by the presence of distinct, narrowly parallel lateral carinae on the dorsal surface of the pronotum; the area between the carinae is marked with a brown stripe that continues over the occiput of the head and the dorsal surfaces of antennal basal segments ( Fig. 23A ). Tegmina often carry white and brown spots that effectively mimic necrotic damage seen on leaves. ( Fig. 23B ).

Bioacoustics. The call of A. exigua is a soft trill, audible from a far distance. The call is a train of short, nearly pure-tone echemes, each consisting of 4–5 syllables; mean syllable duration is 0.11327 s (SD=0.022119, n=84); the peak frequency of the call is 11.7–12.0 kHz ( Figs. 57 A–C).

Distribution and natural history. A. exigua is found across East and southern Africa, from Kenya and Tanzania, through Zimbabwe ( Hemp 2013a), Mozambique, and South Africa. It is a predominantly arboreal species that occurs in a variety of habitats, from closed canopy miombo woodland to village gardens to sub-montane savanna. Nymphs ( Fig. 5C ) have been seen feeding on leaves Grewia sp. ( Tiliaceae ) although adults can be found on many other broad-leaved tree species.

Measurements (3 males, 3 females). body w/wings: male 35–37 (361), female 44–48 (462); body w/o wings: male 22–25 (231.7), female 25–28 (26.31.5); pronotum: male 4, female 5–6 (5.3.6); tegmen: male 30–31 (30.3.6), female 38–41 (39.31.5); hind femur: male 9–12 (111.7), female 13–14 (13.7.6); ovipositor: 10–14 (122) mm.

Material examined (38 specimens). Mozambique: Cabo Delgado, Macomia, Quirimbas N.P., Muanona, elev. 124 m (-12.15117, 40.19542), 24–25.i.2014, coll. P. Naskrecki, H. Farooq, B. Nassongole— 1 female ( MCZ); Manica, Sussundenga, Moribane Forest, swamp on Rio Tave, elev. 518 m (-19.74072, 33.32133), 2–8.xii.2018, coll. P. Naskrecki & M. Tomás— 2 males; Sofala, Coutada 12, Nyago hunting camp, elev. 70 m (-18.660767, 35.455603), 8–16.iv.2016, coll. P. Naskrecki & J. Guyton— 1 male ( EOWL); Gorongosa , GNP, Bela Vista ranger outpost, elev. 26 m (-18.69470, 34.20853), 5–12.v.2015, coll. P. Naskrecki— 1 female, 1 male, 1 nymph ( EOWL, MCZ); GNP, Chitengo, E.O. Wilson Laboratory, elev. 48 m (-18.977722, 34.351333), 9.ii.–4.iii.2015, coll. P. Naskrecki and R. Guta— 1 male ( EOWL); GNP, Murombodzi Waterfall, nr. Mt. Gorongosa , elev. 842 m (-18.483361, 34.042944), 21–22.v.2015, coll. P. Naskrecki— 2 males ( EOWL, MCZ); Gorongosa Dist., Archway Gorge, campsite, elev. 63 m (-18.95336, 34.61089), 22–29.iv.2013, coll. P. Naskrecki— 3 females, 2 males, 2 nymph females, 1 nymph male ( MCZ); GNP, Chitengo, elev. 38 m (-18.978808, 34.352606), 5–9.v.2014, coll. R. Guta— 1 male ( EOWL); Claud’s Waterfall campsite, elev. 94 m (-19.03011, 34.67592), 1–6.v.2013, coll. P. Naskrecki— 1 male; GNP, Chitengo, elev. 29 m (-18.98194, 34.35122), 9.v.–29.vi.2012, coll. P. Naskrecki— 1 female, 1 male ( MCZ); same locality, 17.iii.– 5.iv.2013, coll. P. Naskrecki— 2 males ( EOWL, MCZ); same locality, 6–31.v.2013, coll. P. Naskrecki— 2 males, 1 nymph female; same locality, 30.i.–13.ii.2014, coll. P. Naskrecki— 1 female ( MCZ); Mt. Gorongosa , Gorongosa Nat. P., 21.vii.2015, coll. Calton Sengwaio— 1 male ( EOWL); GNP, along Pungue Rd, nr. Vinho Rd., elev. 25 m (-18.99675, 34.365806), 11–16.vi.2014, coll. P. Naskrecki & R. Guta— 1 male ( EUMM); Sofala Prov., Bela Vista Camp, (-18.695083, 34.209389), 6.v.2015, coll. T. Massad— 3 females, 1 male, 2 nymph females ( EOWL); Bela Vista, machamba near Nharicenguere river, (-18.6963, 34.207467), 8–12.v.2015, coll. R. Guta— 1 male ( MCZ).

Figures

FIGURE 5. Nymphal instars of Mozambican Tettigoniidae (not to scale): A. Ovonotus abreuae, 2nd instar; B. Enyaliopsis iaculator, 1st instar; C.Acauloplax exigua, penultimate instar; D. Cymatomera denticollis, 5th instar; E. Anarytropteris chirinda, 3rd instar; F. Pseudorhynchus pungens, 3rd instar; G. Plangia graminea, 2nd instar; H. Eurycorypha sp., 1st instar; I. Horatosphaga serrifera, penultimate instar; J. Peringueyella megacephala, 2nd instar.

FIGURE 23. Mozambican Pseudophyllinae: A. Acauloplax exigua, male, dorsal view; B. ditto, female, lateral view; C. ditto, male subgenital plate; D. male cerci; E. Zabalius ophthalmicus, male, dorsal view; F. ditto, lateral view; G. ditto, male subgenital plate; H. ditto, male, frontal view.

FIGURE 57. Oscillograms and power spectra of Mozambican Pseudophyllinae:A–C. Acauloplax annulicornis; D–F. Zabalius ophthalmicus; G–I. Cymatomerella spilophora, Type I call; J–L. ditto, Type II call.