Periplaneta australasiae

Blatta australasiae Fabricius 1775: 271; the Pacific and unknown regions (“nave e mare Pacifico et regionibus incognitis revertente”…).

Diagnosis. Adults 27–30 mm, with full tegmina in both sexes; elongate oval, dark brown; pronotum bicolored, disc with yellow encircling a large brown central area, which is sometimes weakly divided into two; outer basal margin of tegmina with a yellow costal edge; supra-anal plate of male rectangular, with a shallow emargination, opaque, reddish brown; supra-anal plate in female folded downward on each side, apically emarginate with apices rounded, dark brown; cerci flat, elongate spindle-like, almost as long as mid tarsi, articles broader than long except last one. Nymphs black, with 2 yellow transverse bands strikingly on pronotum and irregular lateral spots on rest of dorsum.

Comments. The likely tropical origin and spread around the world have created multiple synonyms for Periplaneta australasiae. This is an edificarian pest like its congener P. americana (Species 23), and probably arrived via cargo shipments from abroad. Because of its superficial resemblance to P. americana and collector bias, specimens were rarely collected. Its spread over the Virgin Islands should be interesting for geological, historical, and ecological aspects. Collecting efforts on other islands, especially those not inhabited, should be made. It can be easily distinguished from the widespread P. americana by the yellow costal edge of its tegmina. It is a nocturnal ground-dweller (Table 1); individuals were active at night in the orchard and in the hotel area, mingling with P. americana. Shelford (1910) reported this species from St. Thomas; it is common and herein recorded for the first time on Anegada, Guana, Jost Van Dyke, Moskito, and Tortola of BVI, in addition to other previous records on St. Thomas, Puerto Rico, and other Antillean islands (Princis 1966).

Specimens examined. BDVC —1 nymph, BVI, Anegada Is., airport vicinity, 22.X.2004, Valentines & Sibleys; 1 male, BVI, Guana Is., 2003, W.-P. Liao; 1 adult (abdomen missing), BVI, Guana Is., 27.IX.2005, B. D. Valentine & S. C. Valentine-Cooper, at UV; 1 female /1 nymph, BVI, Guana Is., 14.X.2007, W. Lu, sweep; 1 female, BVI, Guana Is., 9-15.X.2002, B. & B. Valentine, at UV; 1 female, BVI, Guana Is., 26.IX.2005, B. D. Valentine & S. C. Valentine-Cooper; 1 nymph, Jost Van Dyke, 18-19.X.2010, W. Lu & S. C. Valentine-Cooper; 1 male / 1 female, BVI, Moskito Is., 23.X.2008, Valentine-Cooper & Lu; 1 nymph, BVI, Tortola Is., Chalwell, 16-24.X.2003, C. Petrovic, at light.