Podolestes parvus, Dow & Ngiam, 2019

Dow, Rory A. & Ngiam, In. W. J., 2019, A new species of Podolestes Selys, 1862 from peat swamp forest in Sarawak (Odonata: Zygoptera: Argiolestidae), Zootaxa 4586 (3), pp. 505-516 : 507-514

publication ID	https://doi.org/ 10.11646/zootaxa.4586.3.7
publication LSID	lsid:zoobank.org:pub:A45BD48D-446F-4819-AF73-40FC4409C9F5
persistent identifier	https://treatment.plazi.org/id/03B5686E-4F74-FFC5-DFCE-EDD2FA7A85AC
treatment provided by	Plazi
scientific name	Podolestes parvus
status	sp. nov.

Treatment

Podolestes parvus sp. nov.

( Figs 2, 4 View FIGURES 1–4 , 6, 8 View FIGURES 5–8 , 11, 12 View FIGURES 9–12 , 15, 16 View FIGURES 13–16 , 19, 20 View FIGURES 17–20 , 23, 24 View FIGURES 21–24 , 28 View FIGURES 25–28 , 30, 32 View FIGURES 29–32 , 35, 36 View FIGURES 33–36 , 38, 40 View FIGURES 37–40 , 41 View FIGURE 41 , 42, 43, 44, 45 View FIGURES 42–45 )

Podolestes new species;—Dow et al. 2015a: 6767, Image 5 (♂, ♀♀ Maludam National Park).

Holotype. 1 ♂ (SAR11_12_ MEG79 ), perched low on stick over hole, peat swamp forest, Maludam National Park , Betong Division, Sarawak, Malaysia, 1.6188N, 111.0584E (approx. coordinates), 10 vii 2012, leg. R.A. Dow, in RMNH (Leiden). GoogleMaps

Paratypes. In coll. Dow unless stated otherwise, all from Sarawak, Malaysia: 1 ♀ (SAR11_12_ MEG95 ), perched by a track through peat swamp forest, Maludam National Park , Betong Division, 7 vii 2012 , leg. R.A. Dow; 1 ♀ (SAR11_12_ MEG96 ; RMNH.INS.506881), same data but in RMNH; 1 ♀ ( SAR15 _ ARG3 ), in peat swamp forest, same national park, 30 vi 2015 , leg. R.A. Dow; 1 ♀ ( SAR15 _ ARG4 ), same location and date , leg. H. Hasbi & L. Ului; 1 ♂ ( SAR15 _ ARG1 ), on transect between 2 and 3 km inside peat swamp forest, Ulu Sebuyau National Park , Samarahan Division, 1.4016N, 110.9325E (approx. coordinates), 30 i 2015 GoogleMaps , leg. R.A. Dow, to be deposited in SMSM; 1 ♂ ( SAR15 _ ARG2 ), same location and date GoogleMaps , leg. L. Southwell; 1 ♂ (teneral, SAR18 _ ARG9 ), 1 ♀ ( SAR18 _ ARG10 ), disturbed peat swamp forest near Marau Klasau , Pantu area, Sri Aman Division, 1.1174N, 111.0947E, 15 x 2018 GoogleMaps , leg. R.A. Dow.

Other material. 1 ♀ (SAR11_12_ MEG96 ; RMNH.INS.506881), perched by a track through peat swamp forest, Maludam National Park , Betong Division, Sarawak, Malaysia, 7 vii 2012, leg. R.A. Dow, in RMNH. This has been excluded from the type series merely because it was not available for a final check on variation and measurements .

Etymology. The species is named parvus , a Latin adjective meaning small, in reference to the small size of the species.

Description of holotype male. Head ( Figs 2, 4 View FIGURES 1–4 ). Labium pale yellowish except hooks of labial palps, which are dark brown. Labrum pale blue, narrowly brown along free margin. Mandible bases largely bluish white. Postclypeus shining black, anteclypeus pale blue. Genae mostly pale blue adjacent to mandible bases, very dark brown adjacent to compound eye. Antenna (missing above pedicel on right) with scape black, pedicel black and dark brown with whitish ring at top. Frons and vertex mostly bronzy black, with tiny pale mark in front median ocellus, pale blue marks adjacent to compound eye at ca level of antennae; pair dull pale streaks based on outer edge of lateral ocellus, directed towards rear of antenna base, dull pale mark between ocelli, almost divided centrally, these marks together approximately crescentic. Ocelli whitish. Pale and brown band centrally on upper occiput, narrowly separated from crescentic marking on vertex, continued onto underside. Underside of head mostly black with pale markings around point of attachment of prothorax.

Thorax. Prothorax ( Figs 11 View FIGURES 9–12 , 15 View FIGURES 13–16 ) ground colour brown, propleuron with obscure paler and darker areas. Anterior pronotal lobe brown, except at lateral extremities and centrally to rear, where pale. Posterior pronotal lobe brown with obscure darker and paler areas. Middle pronotal lobe brown with pair large pale blue lateral marks, pair smaller central marks, narrowly divided ( Fig. 11 View FIGURES 9–12 ). Posterior pronotal lobe simple, collar like. Synthorax ( Figs 19 View FIGURES 17–20 , 23 View FIGURES 21–24 ) with mesepisternum brown speckled with pale blue marks, pair of larger pale blue markings adjacent to antealar triangles ( Fig. 19 View FIGURES 17–20 ). Mesepimeron similar, larger, irregular marks at either end adjacent to mesepleural suture, metepisternum pale brown with obscure bluish areas, metepimeron largely pale brown. Mesinfraepisternum marked similarly to mesepimeron, metinfraepisternum pale with darker areas. Venter of synthorax pale. Legs (left anterior missing below trochanter) with coxae pale brownish cream, with black streak on posterior coxa, tiny black marks middle coxa, trochanters similar with black marks on middle and posterior pairs. Femur pale brownish cream, two black rings, one not far below trochanter, other around two thirds length, black above joint with tibia, partially on flexor surface. Tibia mostly pale, black below joint with femur, dark central ring, darker on outer surface. Wings with arc situated slightly distal to Ax 2. 17 Px except left Hw with 15 Px. One post quadrilateral cell in all wings. R 4 proximal to Sn, IR 3 slightly distal to it. Pt greyish brown, almost a rhombus, covering one to two underlying cells.

Abdomen (see Fig. 42 View FIGURES 42–45 ). S1 pale brown. S2 pale brown dorsally, brownish cream laterally, pale blue dorsal mark in basal ca one quarter, almost divided centrally. S3–S8 pale brown, darker apically, with pale blue basal dorsal mark, pale laterally below this. S9 brown with pale blue dorsal mark running to posterior carina but narrowing in apical part. S10 dark brown with sub triangular pale blue dorsal mark ( Fig. 35 View FIGURES 33–36 ), obscure pale areas to either side of this basally. Anal appendages ( Figs 38, 40 View FIGURES 37–40 ): cerci brown, paraprocts pale brown at base, rest dark brown. Cerci longer than paraprocts, in lateral view tapering evenly from base to rounded tip, in dorsal view running almost straight from base to ca one third length where directed inwards and rearwards so that they cross one-another ( Fig. 38 View FIGURES 37–40 ), slightly expanded along inner margin after the turn, tapering to rounded apices. Paraprocts in lateral view contracting from broad base then expanding slightly again to subrectangular apices.

Genital ligula. Terminal segment almost square ended in ventral view, with pair of lateral terminal arms folded back and above segment, narrow at origin but then expanding considerably ( Figs 30, 32 View FIGURES 29–32 ).

Measurements (mm). Abdomen without anal appendages 22, cerci 1.1, Hw ca 20.

Description of female paratype (based on SAR15_ARG4). Pedicel whitish in basal ca two-thirds, rest brown, flagella brown. Frons bronzy black, vertex bronzy black with approximately crescentic brownish cream mark ( Fig. 6 View FIGURES 5–8 ) almost surrounding the lateral ocelli with its lateral parts directed towards the antennae; this joined to subrectangular marking of same colour on occiput.

Thorax. Markings very similar to male except in tiny details (see Figs 12 View FIGURES 9–12 , 16 View FIGURES 13–16 , 20 View FIGURES 17–20 , 24 View FIGURES 21–24 ). 16 Px in Fw and right Hw, 15 Px in left Hw. Pt covering one and most of another underlying cell in all wings, brown ( Fig. 28 View FIGURES 25–28 ).

Abdomen ( Fig. 36 View FIGURES 33–36 ). Cerci dark brown, sharply conical, ca same length as S10. Ovipositor mottled dark and pale brown, styles missing on left.

Measurements (mm). Abdomen without anal appendages or ovipositor ca 21, Hw ca 20.5.

Variation in male paratypes. Aside from small variations in markings, and size variation, there is little variation in the non-teneral males. The basal half of the scape is pale in one of the males from Ulu Sebuyau National Park and the basal two thirds in the other.

Measurements (mm). Abdomen without anal appendages 22–24, Hw 20– 20.5. 14 –17 Px in Fw, 13–16 Px in Hw.

Variation in female paratypes. The female from Sri Aman has a slightly lower density of pale spots on the dorsum of the synthorax. Fw Pt only covering half of a second underlying cell in one paratype.

Measurements (mm). Abdomen without anal appendages 21–22, Hw 20–21. 13–15 Px in Fw, 14–16 Px in Hw.

Diagnosis. Both sexes are easily separated from all others known except P. atomarius by the combination of small size and the speckled pattern of the synthorax. It is separated from P. atomarius by the presence of a pale brown band on the occiput (compare Figs 1 View FIGURES 1–4 , 5 View FIGURES 5–8 with Figs 2 View FIGURES 1–4 , 6 View FIGURES 5–8 ), the lack of a blue mark larger than the others on the mesepisternum near the mesinfraepisternum (present in P. atomarius ) (compare Figs 17, 18 View FIGURES 17–20 with Figs 19, 20 View FIGURES 17–20 ), by the blue dorsal mark on S9 running the length of the segment whereas it is smaller and apically positioned in P. atomarius (compare Figs 33, 34 View FIGURES 33–36 with Figs 35, 36 View FIGURES 33–36 ), and by the ground-colour of all body parts brown rather than black. Both sexes are smaller in P. parvus than P. atomarius, Lieftinck (1950: 44) gives the length of the male abdomen with appendages in P. atomarius as 26.5– 30mm, but in P. parvus it is ca 23–25mm, the same measurements for the female are 25.5–27.5mm in P. atomarius compared with ca 21.5– 22mm in P. parvus . The males of the two species are further separated by the differently shaped ends of the arms of the terminal segment of the genital ligula, more abruptly and further expanded in P. parvus than in P. atomarius (compare Figs 31 and 32 View FIGURES 29–32 ). The differences in the position of the arms of the terminal segment of the genital ligula apparent in Figs 29–32 View FIGURES 29–32 are not likely to be diagnostic but are probably due to the process of extraction. The male anal appendages are very similar in the two species, the most notable difference is that in P. parvus the cerci are slightly longer relative to the paraprocts than in P. atomarius (compare Figs 39 and 40 View FIGURES 37–40 ).

Remarks. The pterostigma is brown or greyish brown in both sexes of P. parvus but yellow cream in most individuals of P. atomarius , becoming darker with age as noted by Lieftinck (1950: 42). However in more mature individuals of P. atomarius examined by the first author the underside of the pterostigma (so the side most visible in unpinned specimens) is brown but the upper side is whitish (compare Figs 25–27 View FIGURES 25–28 with Fig. 28 View FIGURES 25–28 ).

The female is associated with the male by reasonable supposition; it has been found in the same locations and habitats as the males and is not that of any other Podolestes species occurring at these locations.

The holotype male and one of the paratype females are shown in life in Figs 42–45 View FIGURES 42–45 , the distribution in Fig. 41 View FIGURE 41 .