Trichotaenia pepetela Serrano & Capela

Serrano, Artur R. M., Capela, Rúben A. & Oesterle, Andreas, 2015, Three new species of tiger beetles and new data on Cicindelina species from Angola (Coleoptera: Carabidae: Cicindelinae), Zootaxa 4032 (2), pp. 151-178 : 158-164

Trichotaenia pepetela Serrano & Capela sp. n.

( Figs 4 , 5 , 6 b, 7a, b)

Type series. Holotype, ♂; Angola ( BIÉ), Catota (coord.: 14º 00´37.17´´ S, 17º 24´00.33´´ E, 1532 m alt., 323), ( BIÉ), 2.XI.2014, DO, A. Serrano leg. Allotype ♀ and paratypes same locality, 2.XI.2014, 1♂, 1♀, 3.XI.2014, 1♂, DO, A. Serrano leg. Holotype and paratypes deposited in ASC.

Derivatio nominis. The specific epithet, pepetela , is used as a noun in apposition based on the pen name “ Pepetela ” of Artur Carlos Pestana dos Santos, a great Angolan writer descent of Portuguese colones of Benguela, which fought together with MPLA (Popular Liberation Movement of Angola) for liberation of their homeland.

Diagnosis. A winged Trichotaenia species, black coloured with some slight punctual purpurish and bluish or violet reflections on head, pronotum and elytra. Clypeus mostly setose, blackish with some purpurish blue-greenish reflections. Labrum large, rounded and 5-toothed in front, very slightly setose on half posteriad surface with just four whitish marginal sensorial setae, only triangularly doubled blackened in the first basal third (males) or triangularly blackened in the two basal thirds (females). A stripe of dense white recumbent pubescence on genae, continuing behind on the ventral half of proepisterna up to the lateral sides of first five abdominal sternites, where it is much narrower. Sternum and abdominal sternites otherwise glabrous. Antennae barely attaining nearly the half of the elytral length in male, shorter in female; antennomeres 1-4 dark metallic black with bluish or violaceous reflections, antennomeres 5-10 strongly foliated. Elytral shoulders and parts of the disk glabrous. Elytral decumbent pubescence ( Figs 7 a‒7b) covering the lateral sides, from the middle of basal third to the apex where it becomes slightly wider, emitting two rami on disc (one slightly arcuate above the apex and one almost straight and large near the middle). A small tuft of closely and diagonally appressed setae on each side of the base of scutellum and a subsutural elongate tuft of closely appressed setae below the scutellum. Absence of decumbent setae along the suture. Elytral decumbent pubescence leaving three naked areoles in between, one large above the middle stripe, the second one immediately below the middle stripe and a third one smaller between the subapical stripe and the apical area.

Description. Length of Holotype: 10.2 mm. Length of paratypes: 10.1 mm (males), 11.2–11.4 mm (females).

Head ( Figs 5 a‒5b). Wider than long [length: 1.63–2.02 mm (males), 2.05–2.08mm (females), width 2.75–2.78 mm (males) and 3.04–3.10mm (females)], with large eyes, slightly narrower than body ( Fig. 4 ), dorsal colour black with coppery reflections; surface sculpture rugulose, rugae forming irregular longitudinal meshes on vertex and transverse meshes on occiput; rugae straight, more or less parallel on orbital plates and frons; occiput, vertex and frons covered with dense and short piceous decumbent setae, clypeus with sparsely decumbent setae, temples (lateral area of head behind eyes) indistinctly striaterugulose, glabrous, glossy; genae covered with dense white decumbent pubescence; orbital plates with two sublateral setigerous punctures; labrum large, shape nearly semicircular in both sexes ( Figs 5 a‒5b), transverse, wider than long [length: 1.06–1.12 mm (males), 1.34–1.36 mm (females), width 1.47–1.54 mm (males) and 1.71–1.76 mm (females)], anterior margin five-toothed, middle basal half slightly protruding, four sublateral sensorial setae, basal portions covered with few sparse, white decumbent setae (males: 1–10, females: 4–8); colour yellowish with outer margin black, males triangularly doubled blackened in the first basal third, females triangularly blackened almost in the two basal thirds; antennae reaching nearly the half of the elytral length in male, shorter in female; antennomeres 1–4 dark metallic black with bluish or violaceous reflections, antennomeres 5–10 strongly dilated and foliated, more pronounced in females; mandibles four-toothed, black with a large yellow patch basally on outer edge; maxillary and labial palpi light yellow, except terminal palpomeres black with metallic reflections; penultimate palpomere of labial palpus moderately inflated.

Thorax. Pronotum ( Figs 5 c‒5d) more or less as long as wide (1.0–1.1 times) [length: 1.82–1.98 mm (males) and 2.02–2.10 mm (females); width: 1.86–1.94 mm (males) and 2.08 mm (females)], subcordiform-shaped, the anterior margin slightly larger [width: 1.74–1.82 mm (males) and 2.05 mm (females)] than the posterior one [width: 1.70–1.73 mm (males) and 1.95 mm (females)]; black, on each side with a broad sublateral band with cupric reflections, this bands are covered with dense piceous decumbent pubescence, which is transversaly directed on median lobe, oblique on posterior and anterior lobes; along each side of median lobe and on central portions of anterior and posterior lobes a few additional thin piceous setae; surface of pronotum rugulose, rugae forming irregular meshes on latero-dorsal and dorsal portions; dorsal half of proepisterna glabrous, ventral half densely covered with white decumbent pubescence which continues that of genae and extends to mesepisterna, metepisterna, lateral portions of metasternum and metacoxae to lateral portions of the first five abdominal sterni; proepisterna slightly visible from above; coupling sulcus: a deeply pitted, funnel-formed impression centrally in upper half of mesepisternum.

Elytra ( Figs 7 a‒7b) longer than wide (1.8–1.9 times) [(length: 6.27–6.47 mm (males) and 7.13–7.26 mm (females); width: 3.33–3.46 mm (males) and 3.90–3.96 mm (females)], subrectangular-shaped, elongated (males) ( Fig. 7 a), more convex and enlarged (females) ( Fig. 7 b), shoulders smooth and glossy very marked, apex ending in a short but acute sutural spine in both sexes, disc surface sculptured by coarse, but very densely arranged polygonal (quadrangular to hexagonal) alveoli most slightly flattened walled in the middle and posteriad half, apical margin with distinct microserrulation; posteriad disc near suture not (males) or slightly protruding in relief in its uppermost region (females); colour of elytra black with more or less coppery lustre only in the pubescent areas, otherwise with some bluish or violaceous reflections; Elytra with white-piceous decumbent pubescence ( Figs 7 a‒7b), consisting of a marginal band, from the middle of basal third to the apex where it becomes slightly wider, emitting two rami on disc, one almost straight and large near the middle and another subapical slightly arcuate; a small tuft of closely and diagonally appressed setae on each side of the base of scutellum and a subsutural elongate tuft of closely appressed setae below the scutellum. Absence of of sparce or decumbent setae along the suture.

Ventral surface. Black, with stronger coppery-golden reflections in head and thorax parts, violet lustre in abdominal sternites; sides of these sternites, except the ultimate, with decumbent pubescence, becoming sparser towards apex; trochanters black.

Legs. Metallic black with greenish reflections in tarsi and violaceous-bluish in femora and tibiae, a few rows of spiniform setae on femora and tibiae;

Aedeagus ( Fig. 6 b) relatively small (length: 2.64–2.78 mm), arched, tapering, with a straight, simple apex.

Intraspecific variation. The range of variability observed in T. pepetela sp. n. (5 specimens) affects slightly the number of labral decumbent setae (see description), but not the elytral decumbent pubescence. As happens with T. nzingae sp. n. the shapes of pronotum and elytra are very conservative, but variation in the length of the apical denticle of elytra is very common, with individuals having longer denticles than others. Asymmetries in the length of left and right elytron denticles within the same specimen are common too.

Remarks. A total of fifteen species, including the two new ones, are known so far within the genus Trichotaenia . Cassola (1983) revised the eight then known species of this Afrotropical genus and Schüle (2011) provided an identification key for the thirtheen then known species. Until now the genus was represented in Angola by two species [ T. pseudosuturalis (W. Horn, 1914) and T. suturata (W. Horn, 1915) ] ( Serrano & Capela 2013).

The Trichotaenia species can be included in some artificial groups based on two sets of characteristics ( Table 1 ). Two groups are easily discriminated based on the presence / absence of full wings, a condition that is correlated with the evidence of distinct elytral humeri against effaced elytral humeri and three groups based on the presence / absence of decumbent setae on the labrum. So far, it has not been proved to be any phylogenetic mean of these features, but they are practical to discriminate those groups of species. A lot of eight species seems to share both the elytral humeri distinct plus the labrum setose [ T. duplosetosa (W. Horn, 1929) , T. kudrnai Cassola, 2008 , T. nzingae sp. nov., T. pepetela sp. nov., T. pseudosuturalis (W. Horn 1914) , T. pseudotereticollis (W. Horn, 1929) , T. rivalieri Basilewsky, 1958 and T. suturata (W. Horn, 1915) ] and other three the elytral humeri effaced plus the labrum glabrous ( T. mireki Werner, 2003 , T. mufumbweana Cassola, Werner & Schüle, 2009 and T. mwinilungae Cassola, Werner & Schüle, 2009 ). The remaining four species, by presenting either the labrum setose or glabrous [ T. africana Cassola, 1983 and T. tereticollis (Boheman, 1860) ] or by presenting a distinct elytral humeri plus a glabrous labrum ( T. allardi Cassola, 1983 ) or even exhibiting elytral humeri effaced plus a setose labrum ( T. minettii Schüle, 2011 ) do not enter wholy in the two former groups ( Table 1 ).

Species Labrum Elytral humeri The two new species belong to the first group presenting well distinct elytral shoulders as well as a labrum more ( T. nzingae sp. n.) or less ( T. pepetela sp. n.) setose. Within this group both new species, and taking into account the morphological characters, are more akin with T. pseudosuturalis and T. pseudotereticollis . However, they can be segregated from the former species by the position of the elytral median transverse decumbent setae stripe located around or slightly after the middle (located before the middle in T. pseudosuturalis ), by the presence of a subapical arcuate decumbent stripe of setae (absent in T. pseudosuturalis ) and even by the absence of sparse pubescence on shoulders (present in T. pseudosuturalis ). Both new species can be discriminated from the later species also by the shoulders slightly more distinct and the shape of pronotum which is slightly cordiform (subrectangular in T. pseudotereticollis ). Moreover Trichotaenia nzingae sp. n. can be discriminated from T. pseudotereticollis by a pronotum slightly wider than long, a different elytral decumbent setae distribution pattern (cf. Figs 3 and 7 d) and the alveoli of the elytral disk slightly sharply walled (most flattened walled in T. pseudotereticollis , conferring to this species a coppery lustre on whole disk, but not in the new species). On the other hand, Trichotaenia pepetela sp. n. can be separated also from T. pseudotereticollis by a very different elytral decumbent setae distribution pattern (cf. Figs 7 a‒7b and 7d) and labral blackish colour pattern. Both new species can be discriminated easily from T. allardi by the 5–9 antennomeres enlarged and foliated and the setose labrum, from T. duplosetosa by the absence of depigmented areas in the elytrae, from T. suturata by a very different elytral pubescence pattern (cf. Figs 3 , 7 a‒7b and 7e, see also Plate 46, Fig. 12 in Horn 1938), from T. rivalieri by the shape of pronotum (cordiform or subcordiform vs. subquadrate) and the very distinct notopleural suture and from T. kudrnai by the position of the elytral median transverse decumbent stripe of setae located around or only slightly after the middle and the presence of a transverse and arcuate subapical band (cf. Figs 3 , 7 a‒7b and Fig. 1 in Cassola 2008).

The two new species are very close also with T. tereticollis , a species with distinct shoulders, but with labrum either setose or glabrous. Both new species can be segregated from T. tereticollis by a different elytral pubescence pattern (cf. Figs 3 , 7 a‒7b and 7c) as well as the shape of pronotum.

The two new species are easily discriminated between them by some features such as the elytral decumbent setae distribution pattern (cf. Figs 3 and 7 a‒7b), prothoracic epipleura visible ( T. pepetela sp. n.) or not ( T. nzingae sp. n.) from above and elytral punctures in apical half not anastomosing to longitudinal chains ( T. nzingae sp. n.) or conversely anastomosing to longitudinal chains ( T. pepetela sp. n.). Finally both new species, by the distinct elytral shoulders, are easily separated from the remaining species of Trichotaenia which are characterized by more or less effaced humeri, among other characters.

Ecological remarks. Both Trichotaenia new species are until now restricted to Angola. The adults were found together with some adults of other tiger beetles (see also P. angusticollis ecological remarks concerning Kakande and Catota localities) in countryside roads of whitish sandy soil. At such roads and paths with sand-clayish soil (or even small fields) in secondary open forest, T. nzingae sp. n. could be observed at the Cachingues localities rather at the margins with darker soil, litter and herbaceous plants. Other sympatric tiger beetles (with preferences of their micro-habitats) have been P. angusticollis (litter), D. serietuberculata f. lundana (litter), O. rofomarginata poggei (white sandy soil), L. infuscatula (white sandy soil), E. muata f. parallelestriata, (dark soil), L. saraliensis (dark soil), D. similis and C. agualusae sp. n. Unlike to what was said by Cassola et al. (2009) that “all Trichotaenia species, even if normally winged, never fly and prefer to rapidly run on the ground through the grasses”, most of the adults of both new species were captured when attempted to fly rapidly into the neighbouring open secondary forest. Some specimens were captured also on the ground when attempted to run into the edges of the roads, but this behaviour seems more connected with the lower environmental temperature conditions in early morning or later near dusk or even under overcast sky.

Figures

FIGURE 1. Facies of Trichotaenia nzingae sp. n.: a) male holotype, b) female allotype.

FIGURE 3: Trichotaenia nzingae sp. n., elytra (dorsal view): a) typical decumbent setae pattern, b ‒ d) examples of variability among the decumbent setae pattern.

FIGURE 4. Facies of Trichotaenia pepetela sp. n.: a) male holotype, b) female allotype.

FIGURE 5. Trichotaenia pepetela sp. n., head, mandibles and labrum, pronotum (dorsal view): a, c) male; b, d) female.

FIGURE 6. Aedeagus (lateral view): a) Trichotaenia nzingae sp. n., paratype, Kakande, Bié, Angola, b) Trichotaenia pepetela sp. n., holotype, Catota, Bié, Angola.

FIGURE 7. Elytra (dorsal view): a and b) Trichotaenia pepetela sp. n., male and female, respectively, c) Trichotaenia tereticollis (W. Horn), d) Trichotaenia pseudotereticollis (W. Horn), e) Trichotaenia suturata (W. Horn).

FIGURE 12. Aedeagus (lateral view) and median lobe apex (ventral view): a) Cylindera agualusai n. sp., paratype, Cachingues ‒ Chipica, Angola; b) Cylindera lutaria (Guérin-Méneville), Canchungo ‒ Calequisse, Guinea-Bissau.

Tables

TABLE 1. Artificial groups of Trichotaenia species based on two sets of characters: presence or not of labral pubescence and elytral humeri distinct or effaced. Within each set of characters, groups are joined simultaneously by the same background color and the same small letters.

	With decumbent setae	Glabrous	Distinct	Effaced
T. africana Cassola, 1983	+(a)	+(a)	-(d)	+(d)
T. allardi Cassola, 1983	-(b)	+(b)	+(e)	-(e)
T. duplosetosa (W. Horn, 1929)	+(c)	-(c)	+(e)	-(e)
T. kudrnai Cassola, 2008	+(c)	-(c)	+(e)	-(e)
T. minettii Schüle, 2011	+(c)	-(c)	-(d)	+(d)
T. mireki Werner, 2003	-(b)	+(b)	-(d)	+(d)
T. mufumbweana Cassola, Werner & Schüle, 2009	-(b)	+(b)	-(d)	+(d)
T. mwinilungae Cassola, Werner & Schüle, 2009	-(b)	+(b)	-(d)	+(d)
T. nzingae sp. n.	+(c)	-(c)	+(e)	-(e)
T. pepetela sp. n.	+(c)	-(c)	+(e)	-(e)
T. pseudosuturalis (W. Horn, 1914)	+(c)	-(c)	+(e)	-(e)
T. pseudotereticollis (W. Horn, 1929)	+(c)	-(c)	+(e)	-(e)
T. rivalieri Basilewsky, 1958	+(c)	-(c)	+(e)	-(e)
T. suturata (W. Horn, 1915)	+(c)	-(c)	+(e)	-(e)
T. tereticollis (Boheman, 1860)	+(a)	+(a)	+(e)	-(e)