Antonina thaiensis Takahashi 1942

Antonina thaiensis Takahashi 1942: 15; 1951: 21; Ali 1970: 101; Ben-Dov 1994: 42; Hendricks & Kosztarab 1999: 123; Williams 2004: 78.

Antonina zonata Takahashi 1951: 21 .

Material examined: INDIA, Karnataka, Bengaluru: Yelahanka, Gandhi Krishi Vigyan Kendra, N 13.0801°, E 77.5785°, on Bambusa vulgaris Schrad. ex J.C. Wendl. (Poaceae), 24.viii.2016, B. Manjunath coll., 10 ♀♀; Dollars colony, N 13.0415°, E 77.5684°, on B. vulgaris, 25.iv.2018, Sunil Joshi coll., 9 ♀♀; Hebbal, Bhuvaneshwari Nagar, N 13.0545°, E 77.6036°, on B. vulgaris, 25.iv.2018, Sunil Joshi coll., 4 ♀♀; Ganesh Nagar Layout, Kodigehalli, N 13.0697°, E 77.5788°, on B. vulgaris, 19.v.2021, R. R. Rachana coll., 18 ♀♀.

Appearance in life (Fig. 1e): Adult females form dense colonies near the internodes of bamboos, usually inside the leaf sheaths. Adult female dark brown, partially covered in white wax on anterior end, abdominal dorsum without wax coating but body resting on a cushion of white wax, perhaps secreted by ventral dermal pores. Body elongate, almost parallel sided with rounded ends, and with a long white wax tube projecting from posterior end. Immature stages reddish brown.

Diagnosis of slide-mounted adult female (n=41): Body elongate- to broadly oval (Fig. 7q); anal lobes weakly developed. Abdominal segments VI–VIII highly sclerotized laterally; mature female becoming heavily sclerotized throughout. Antennae each 2 segmented (Fig. 7a). Legs and leg vestiges, eyes and ostioles absent. Anal ring situated at inner end of anal tube (Fig. 7b), bearing 6 thick pointed setae. Vulva directed posteriorly, with heavily sclerotized lateral apophyses (Fig. 7c) and weakly sclerotized posterior apophyses.

Dorsum: With short, pointed setae (Fig. 7d). Marginal setae conical (Fig. 7e).

Venter: Multilocular disc pores (Fig. 7f), each with 10–12 loculi, present around margins, scattered on head and prothorax and a few present near median areas of posterior abdominal segments and within orifice of anal tube. Trilocular pores (Fig. 7g) thick-rimmed, fairly numerous on head, thorax, and anterior abdominal segments, forming almost elongate groups across segments and around margins of meso- and metathoracic segments and abdomen. Discoidal pores of 2 sizes, each with a heavily sclerotized rim (Fig. 7h) and smaller than a trilocular pore. Tubular ducts of 2 sizes: a large type (Fig. 7i), with a narrow flange and transverse, almost quadrate inner end, sparsely present near margins of abdominal segments VII and VIII, and together with multilocular disc pores situated internally within orifice of anal tube; and a small type of duct (Fig. 7j), with almost quadrate inner end, fairly numerous on abdominal segment VII, associated with groups of trilocular pores. With short, pointed setae (Fig. 7k) similar to those on dorsum, longer on posterior abdominal segments (Fig. 7l); a pair of thick apical setae present. Disc-like pores (Fig. 7m), each with a thick rim and reticulated surface, numerous in submarginal groups on metathorax and abdominal segments II and III; some pores also present between anterior and posterior spiracles. Multilocular disc pores same as those on dorsum, a few present immediately posterior to vulva (Fig. 7n); others forming medial transverse rows on abdominal segment III and posterior segments, and a band around margins and submargins (Fig. 7o) as far forward as head. Multilocular disc pores present also on thorax, on area surrounding each anterior spiracle and some reaching posterior spiracles; others sparsely distributed on medial areas of thorax. Discoidal pores (Fig. 7p) of same 2 types as those on dorsum, scattered.

Comparison: Our diagnosis mostly agrees with the description and illustration by Williams (2004).

Ecological notes: Antonina thaiensis was first described from Thailand (Takahashi 1942) and was later recorded in Malaysia in the 1940s (Takahashi 1951), Indonesia (Java) in 1957 (Sartiami et al. 2016) and more recently in Sri Lanka (Sirisena et al. 2012); this suggests that the species is slowly spreading from Southeast Asia to southern Asia, infesting mainly species of bamboos, and hence may spread to different parts of India where ornamental bamboos are commonly grown in parks and gardens. The parasitoid Microterys imphalensis Singh & Hayat ( Hymenoptera: Encyrtidae) (Fig. 7n) was found parasitizing the mealybug in fairly large numbers. No other natural enemies have been recorded from A. thaiensis from other parts of the world. Microterys imphalensis was described by Singh & Hayat (2002) from Manipur on an unknown host. The present record of this parasitoid attacking A. thaiensis is its first host record, as well as a new distribution record for southern India. No ant species was observed attending the mealybug.