Pterotiltus hollisi Rowell 2005
Creators: name: Rowell, C. H. F.
name: Oumarou-Ngoute, Charly
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Acrididae
Pterotiltus
Pterotiltus hollisi

description: 13. Pterotiltus hollisi Rowell, 2005
Figs 35–38; Table 11
Pterotiltus hollisi Rowell, 2005: 34.
Pterotiltus hollisi – Rowell & Hemp 2017: 86.
Type material
Holotype
UGANDA • ♂; Buganda, Mpigi District, Mpanga Forest Reserve; 13 Mar. 1998; C.H.F. Rowell leg.; NHMUK 98034.
Paratypes
UGANDA • 1 ♀; same data as for holotype; NHMUK 98032 • 1 ♀; same data as for holotype; RC 98033 • 1 ♀; Buganda, Mpigi District: Mpanga Forest Reserve; 5 Jul. 1992; C.H.F. Rowell leg.; RC 92013 • 1 ♂; Buganda, Mpigi District: Mpanga Forest Reserve; 4 Jul. 1992; C.H.F. Rowell leg.; RC 92008 • 1 ♀; Tooro, Kabarole District, Kibale Forest, Kanyawara; 29 Mar. 2003; C.H.F. Rowell leg.; RC 2003073 • 1 ♂; same data as for preceding; 2 Apr. 2003; C.H.F. Rowell leg.; RC 2003079 • 1 ♂; same data as for preceding; 3 Mar. 2003; C.H.F. Rowell leg.; RC 2003074 • 1 ♂; Buganda, Mukono District, Mabira Forest, 5 km E of Najjembe; 8 Mar. 1998; C.H.F. Rowell leg.; RC 98006.
Other material examined
RWANDA • 1 ♀; contref. Est Muhavura; 2100 m a.s.l.; 28 Jan. 1952; P. Basilewsky leg.; RMCA. This specimen (Fig. 34) was determined erroneously as berlandi by Dirsh (1955). It is probably in fact P. hollisi – see Taxonomic remarks below – and not berlandi.
UGANDA • 1 ♂; Tooro: Kabarole District, Kibale Forest National Park, Kanyawara; 19 Mar. 2003; C.H.F. Rowell leg.; RC 2003056 • 1 ♀; Tooro: Bundibugyo District, Semliki National Park, Bumaga-Ntandi trail; 22 Aug. 2006; C.H.F. Rowell leg.; RC 2006278.
Approximately 50 other specimens, all from S or W Uganda, detailed in Rowell 2005 (MUMZ).
Description (condensed from Rowell 2005)
Small/medium size, average body length males 16.05 mm, females 19.86 mm. Antennal flagellum of 22 segments. Integument generally smooth and shiny; but frons, genae, pronotum, terga of meso- and metathorax and of first abdominal segment coarsely pitted. Mesosternal interspace longer than broad.
Male (Figs 35, 37–38)
Fastigium slightly concave, with an irregular surface and somewhat thickened margins. In most but not all individiduals there is a weak medial longitudinal groove at the anterior end of the fastigium. Furcula small and simple, with broadly triangular points. Cerci straight, simple, laterally compressed, narrowing before tip, pointed.
PHALLIC COMPLEX. Epiphallus (Fig. 37B–C) wide, divided, with a large outer pair and smaller inner pair of lophi, ancorae absent; oval sclerites present, teardrop shaped. Ectophallus: large ventrolateral sclerite present, encircling the lower half of the phallus. Apodemes of cingulum short and broad, anterior ends widely separated; rami extending ventrally, bulging convexly towards the rear, and meeting ventrally under the endophallus. Phallic membrane posterior to zygoma of cingulum produced into a sheath which covers the aedeagus. Endophallus as in generic diagnosis; note this supercedes the description previously given in Rowell (2005), which was written before a complete understanding of the oxyine phallus had been obtained. The valvular plate (Fig. 38A–D) is highly developed and unusually complex. The paired medial lobes form closely spaced vertical lamellae ventrally, but dorsally, where they fuse with the lateral lobes, each expands into a horizontal leaflike form, reflexed cephalad at their upper extremity, the tips almost touching the cingulum. The more ventral parts of the lateral lobes form a cupshaped container around the medial lobes.
Female (Fig. 36)
Ovipositor as in generic diagnosis. Posterior margin of subgenital plate smoothly triangular, with a long, straight, pointed egg guide, laterally compressed at the tip and rather oblong in profile, and 1 pair of large, sclerotized columellae. Bursa copulatrix large, the walls ornamented with short projections, somewhat asymmetrical distally, but not as pronouncedly so as in P. impenni s (Fig. 2). Spermathecal duct fairly short; spermatheca simple with a hooked terminal ampulla (Rowell 2005: fig. 5c), lacking the small lateral diverticulum seen in P. impennis (Fig. 2).
Colouration (in life) (Figs 35–36)
Antennae black, tipped greenish white. Eyes black. Vertex, fastigium, upper genae, black. Frons white, densely speckled grey-green. Palps and proximal parts of mandibles pale green. Lower genae white tinged with gold, increasingly speckled with green towards their anterior margins. The white band of the genae is continued backwards across the pronotal lobes and epimera and episterna of the meso- and metathorax. Dorsal half of thorax and the first 3 abdominal segments black, ventral half green. Rest of abdomen olive green, including genitalia. Paired spots on dorsa of pronotum, metathorax and 1 st abdominal segment, gold or yellow. Middle and forelegs green, tarsal segments blue-green, underside and aroleum reddish. Hind femur leaf green, upper part of knee black, ventral lobes blue; hind tibia blue, with a leaf green post genicular band. Hind tarsi pinkish white, aroleum pink.
In the female the white areas of the pronotum are often tinged with yellow or pink, the abdomen can be tinged with olive brown, and the areas of the legs that are blue in males are greyer in colour.
In dried museum material the blue colour tends to be lost and replaced by green, and in badly discoloured specimens the green itself is replaced by yellow. The eyes turn brown when dried. Alive in the wild, this is a black and green insect with prominent white or yellow spots on the dorsum. Note: hollisi has black, not red, hind knees. To date, all other known species of Pterotiltus from the Congo Basin have red knees, except for the Atlantic coastal P. campoensis, some individuals of P. inuncatus, and the various Parapterotiltus spp.
Measurements
See Table 11.
Ecology
Rowell (2005) gives some natural history information, including this species’ epiphyllic oviposition on the food-plants (Marantaceae, Commelinaceae).
Distribution
Common in forests of southern and western Uganda, but not occcuring east of the Victoria Nile. Probably extends from W Uganda into NW Tanzania and extreme E DR Congo. Probably also occurs in N Rwanda; the Muhavura specimen cited by Dirsh (1955, 1970) as P. berlandi (RMCA Tervuren, examined; Fig. 34) is a female, and discoloured; it may have been pinned from an original alcohol preparation. Compared to the paratype female of berlandi, it seems to differ slightly in structure, as well as in aspects of colouration. The profile of the frons is straight, whereas that of the berlandi paratype is slightly concave; the anterior margin of the pronotum has a narrower midline projection overhanging the occiput than does the paratype. The hind knees are distinctly darker than the rest of the body, which is not the case in the paratype. It shows no trace of red colouration, either on the abdomen or the clypeus and labrum.
Although we cannot be completely certain that Dirsh’s identification of this specimen as P. berlandi is incorrect, the present authors consider it very probable. An identification as P. hollisi (which had not been described at the date of Dirsh’s determination, and which has black hind knees) is at least equally likely. The faint remaining traces of colouration suggest this, and it is biogeographically much more plausible, as hollisi occurs on the Ugandan (northern) slopes of Muhavura mountain, whereas the specimens of berlandi come from the very distant Atlantic coast. Only fresh material from the Rwandan (southern) side of Muhavura is likely to resolve this uncertainty.
Status of taxonomic material
Good: adequate material of both sexes present in collections, modern localities known.
description: Published as part of Rowell, C. H. F. & Oumarou-Ngoute, Charly, 2025, Review of Pterotiltus Karsch, 1893 (Orthoptera, Acrididae, Oxyinae), pp. 1-104 in European Journal of Taxonomy 986 on pages 60-66, DOI: 10.5852/ejt.2025.986.2853, http://zenodo.org/record/15235428