Pycnoscelus striatus (Kirby, 1903)

Lucanas, Cristian C. & Lit, Ireneo L., 2016, Cockroaches (Insecta, Blattodea) from caves of Polillo Island (Philippines), with description of a new species, Subterranean Biology 19, pp. 51-64 : 56-58

Taxon classification Animalia Blattodea Blaberidae

Pycnoscelus striatus (Kirby, 1903) Figure 3

Leucophaea striata Kirby, 1903: 378 (Lectotype: ♂, Batu Cave, Selangor, Malaysia, BMNH, designated by Princis 1956); 1904: 151; Hanitsch 1915: 122, 163; Chopard 1919: 358; Hanitsch 1923: 445, 466.

Pycnoscelus striatus , Chopard 1924: 82; 1929: 367; Hebard 1929: 14; Hanitsch 1929: 266, 287; Hanitsch 1933: 303, 327; Bruijning 1948: 41, 145; Princis 1958: 70; 1964: 274; McClure 1965: 55; McClure et al. 1967: 418; Roth 1973: 251; Roth 1980: 103; 1998: 117; Price 2004: 314; Lucañas et al. 2015: 2.

Material examined.

22 males, 15 females, 38 nymphs: Philippines: Polillo Island (Quezon Province): Bulalon Cave, Poblacion, Burdeos, v.2010 (JMA Encinares, UPLBMNH BLA-00443-00455 and -00500-00505, ♂; -00456-00466, ♀; -00467-00497, nymphs), 24-27.ii.2007 (IL Lit, Jr/ OL Eusebio, UPLBMNH BLA-00507-00509, ♀); Cave 2, Sitio Puting Bato, Barangay Aluyon, Burdeos, 23.ii.2013 (CC Lucañas, UPLBMNH BLA-00517, ♂; -00518, ♀), 23.v.2013 (CC Lucañas, UPLBMNH BLA-00524 ♂; -00522-00523, nymphs); Cave 3-4, Sitio Puting Bato, Barangay Aluyon, Burdeos, 23.ii.2013 (CC Lucañas, UPLBMNH BLA-00511, -00515, ♂; -00512, -00516, ♀; -00513-00514, nymphs); Cave 5, Sitio Puting Bato, Barangay Aluyon, Burdeos, 24.ii.2013 (CC Lucañas, UPLBMNH BLA-00519-00521, nymphs).

Description.

Size (mm): ♂ TL: 14.25 ± 1.32; BL: 13.59 ± 1.15; Pn: 4.57 ± 0.42 × 5.91 ± 0.65; Tg: 9.68 ± 1.56; ♀ TL: 21.39 ± 1.91; BL: 17.67 ± 1.97; Pn: 5.97 ± 0.40 × 7.42 ± 0.43; Tg: 16.67 ± 1.91.

Male. Often less than half the size of females. Vertex exposed. Ocelli present. Pronotum rhomboid, almost as long as wide, reddish-brown, densely punctured. Tegmina variable, reaching slightly beyond abdomen or reaching only up to 7th abdominal tergite. Fore femur C1. Mid- and hind femur unarmed. Pulvilli present on four proximal tarsomeres. Hind metatarsomere slightly longer than succeeding tarsomeres combined. Tarsal claws simple, symmetrical. Arolia minute. Abdominal tergites un specialized. Supraanal plate entire, testaceous. Genitalia as illustrated. Left style absent. Right style ovoid, rounded apically. Genital hook on right side.

Female. Almost similar to males except larger and robust. Wing size highly variable. Subgenital plate entire.

Distribution.

Malaysia (Malacca), Indonesia (Sumatra, Kalimantan), Philippines.

Ecology.

McClure (1965) noted that Pycnoscelus striatus reaches very high population density, reaching up to 3000/m2 of guano on Batu Caves, Malaysia. Similarly, individuals from Cave 3-4 form dense populations in thick guano from the fruit bat Rousettus amplexicaudatus (Geoffroy, 1810), but are also found in small population on dark zone with thin guano from insectivorous bats. They classified as guanobytes as they burrow beneath layers of guano. They are found together with and may serve as prey to Phlogiellus kwebaburdeos Barrion-Dupo et al., 2014 ( Barrion-Dupo et al. 2014, Rasalan et al. 2015), scutigerid centipedes, Scutigera sp. and some whipspiders, Charon sp.

Remarks.

Roth (1998) reported a female specimen collected from bat guano in Manhuyod or Negros. Roth temporarily assigned it as Pycnoscelus sp C. due to the absence of a male specimen, but stated that it closely resembles Pycnoscelus striatus . The specimen is deposited in the Zoological Institute, Department of Systematics, Lund, Sweden. Several specimens collected from Burdeos have the same interocular width as Pycnoscelus sp. C (2.3mm), while some fit with Pycnoscelus striatus (1.5-1.7mm). Therefore, it is possible that Pycnoscelus sp. C is a variation of Pycnoscelus striatus . Additional specimens, particularly from the same collection locality of Pycnoscelus sp. C, are needed to confirm this.

The foregoing description of the right style (i.e. rounded apically) differs from that of Roth (1998), which he illustrated as acute apically.