Ancyronyx pseudopatrolus Freitag & Jaech , 2007

Freitag, Hendrik & Balke, Michael, 2011, Larvae and a new species of Ancyronyx Erichson, 1847 (Insecta, Coleoptera, Elmidae) from Palawan, Philippines, using DNA sequences for the assignment of the developmental stages, ZooKeys 136, pp. 47-82 : 60-63

Ancyronyx pseudopatrolus Freitag & Jaech, 2007 Figs 513 A–E14A–I

Ancyronyx pseudopatrolus Freitag & Jäch, 2007: 46-47 (adult description).

Material examined.

11L (2 × 0.17, 2 × 0.22, 0.23, 0.24, 3 × 0.27, 0.28, 2 × 0.29) (NMW, ZMUC, CFP) "PHIL.: Palawan, P. Princesa Panaguman R. 10°15'09"N, 118°58'03"E 17.5.2001, leg. Freitag (PR1)D"; 2L (0.23, 0.27) (PCSD) "PHIL.: Palawan, P. Princesa Panaguman R., Marofinas 10°15'09"N, 118°58'03"E 01.8.2001,leg.Freitag(PR1)C-R"; 2L (0.24, 0.28) (SMTD) "PHIL.: Palawan, P. Princesa Panaguman R., Marofinas 10°15'09"N, 118°58'03"E 15.6.2001, leg.Freitag(PR1)C-R"; 3♂♂, 1♀ (UPLB, ZSM [FR003], PCSD, IMRL) "PHIL.: Palawan, P.Princesa; Concepcion, Taranaban R. trib.; mount.creek c.8km upstr.; dist. prim. forest; riffle;rocks, boulders,roots; c.450m asl 10°05'N, 119°01'E, 28.1.1995 leg. Freitag (16f)M"; 3♂♂, 2♀♀ 1L (0.29) (SMTD, ZSM [FR040], NMW, ZMUC, CFP) "PHIL.: Palawan, P.Princesa; Concepcion, Taranaban R.; c.6km upstr. Highw., mount.riv., riffle; boulders, woodlitter; c.150m asl 10°02'30"N, 119°00'45"E, 20.1.1995 leg. Freitag (16b)M".

Remarks.

This species was originally described based on a single male exemplar. As additional material including females have been collected since then we will provide a short diagnosis of the female characters and sexual dimorphisms. Furthermore, the aedeagus (Fig. 13A) is figured in here as SEM micrograph, for the detailed diagnosis see Freitag & Jäch (2007), pp. 41 & 46; Figs 12a, b.

Adult female diagnosis.

Ovipositor as in Fig. 13B. Total length c. 500 µm. Stylus comparably stout as in Ancyronyx punkti (see Freitag & Jäch, 2007, Fig. 13d), slightly conical towards base (broader apically), slightly outwards directed. Coxite long and slender as in Ancyronyx patrolus (comp. Freitag & Jäch, 2007, Fig. 11d); setae rather short, peg-like, apically rounded, not acute, most densely dispersed at coxite apex; mesal coxite margin moderately pubescent; basal portion c. half as long as distal portion, with slightly more acute and pointed setae than those at distal portion, most densely set at proximal and lateral margins. Valvifer about as long as coxite; fibula enlarged and curved inwards at proximal end.

Secondary sexual characters.

Sternite VIII in female (Fig. 13C) overall very similar to that of Ancyronyx punkti , with median strut apically widened and truncate; posterior portion with disc densely covered with small, inconspicuous setae; posterior margin with moderately long trichoid setae. Sternite VIII in male weakly sclerotized, median strut distinctly shorter than in female. Ventrite 5 in female (Fig. 13D) overall very similar to that of Ancyronyx punkti , subtriangular, with small and only slightly elevated lateral projections. Ventrite 5 in male (see Freitag & Jäch, 2007, Fig. 12d) suboval, stouter and with large and distinctly elevated lateral projections. Tergite VIII in female (Fig. 13E) longer than broad; condyles more or less straight; asperities only conspicuous laterally.

Larval diagnosis (based on 6th instar).

Colour (Fig. 5) somewhat similar to that of Ancyronyx minerva and Ancyronyx punkti , but differs slightly in the dorsal and leg colour patterns. Anterior yellow pronotal band very broad, reaching up to anterior 0.4, sublaterally extended posteriad (area of explanate lateral pronotal gutter). Meso- and metanotum and abdominal segments with paler entire posterior margin or entirely dark brown (except for paler posterolateral projections). Colour patterns of head and abdominal segment IX as in Ancyronyx punkti . Legs yellowish pale except for dark distal tibia area around claw insertion.

HW c. 0.29 mm; entire larva about 3.0 mm long. Body shape as in Ancyronyx punkti , except for the following characters:

All abdominal posterolateral projections (Fig. 14A) very prominent, distinctly overreaching posterior segment margins. Setiferous tubercles at dorsal site very prominent and protruding (Figs 14A, B). Ventral side densely covered with asperities and scattered setiferous tubercles (Fig. 14E).

Head (Figs 5; 14 B–D) broadest at c. posterior 0.3, margins not subparallel. Lateral head with clumped stemmata arranged in well defined round, protruding glabrous area (Fig. 14B); lateral setae short and rather inconspicuous; dorsolateral pair of double setae present and long (Fig. 14B); frontal suture V-shaped (Fig. 5). Labium (Fig. 14C) as in Ancyronyx punkti , except for setae and spines of the mentum: sublateral trichoid setae moderately long; lateroapical pair of spines slender, inserted subapically. Antennae, labrum (both Fig. 14D), maxillae and gula (both Fig. 14C) as in Ancyronyx punkti .

Pro-, meso- and metathorax (Figs 5; 14E, F) distinctly narrower anteriorly. Pronotum with conspicuous small signa in posterior half arranged as in Fig. 14E.

Sublateroposterior portions and anteriomedian sclerites of thoracic venters with setiferous tubercles (Fig. 14F); remaining ventral areas densely covered with asperities.

Legs (Fig. 14G) as those of Ancyronyx punkti .

Abdomen (Figs 5; 14A, H–I) with dorsosagittal carinae at the posterior portions of segments I–VIII and most distinct at the almost entire segment IX (Fig. 14I). Squamose setae at posterior rim of segments I–VIII broken off in specimen figured under SEM, but generally developed (Fig. 5). Sagittal ridge of ventral sclerite of segment I longer than 1/2 of segment length. Apex of segment IX slightly emarginate. Operculum (Fig. 14H) medially deeply impressed, rugulose, with few setae at disk.

Variation between larval instars.

For this species, quite a number of prefinal instar specimens is available. They vary from the final instar description by the overall paler colour, relatively longer posterolateral projections, relatively shorter and broader legs and fewer setae on tibiae and femora.

Larval differential diagnosis.

The species can most easily be distinguished from its congeners Ancyronyx minerva and Ancyronyx punkti by the colour pattern of the anterior pronotum and the dorsal posterior margins of thoracic and abdominal segments and the more distinctly developed, protruding tubercles and of the dorsal crest of the abdominal segment IX.

Distribution.

Only known from few rivers in central Palawan.