Stigmacoccus

Hodgson, Chris, Gamper, Heather, Bogo, Amauri & Watson, Gillian, 2007, A taxonomic review of the Margarodoid genus Stigmacoccus Hempel (Hemiptera: Sternorrhyncha: Coccoidea: Stigmacoccidae), with some details on their biology, Zootaxa 1507, pp. 1-55 : 21-23

Stigmacoccus species A

( Fig. 8 )

Material studied. DOMINICAN REPUBLIC, on Haitian border (Sierra de Bahoruco), 11.iii.1999, on Bursera sp., S. Latta ( USNM): 2/7 cysts, 3 large, 4 small, mainly in good condition.

Unmounted material. Not seen.

Mounted material. Slightly oval, large length 1.25–1.6 mm, width 1.3–1.4 mm; small length 1.12–1.38 mm, width 0.95–1.25 mm.

Dorsum. Thoracic segments with a few sparse spines laterally plus a few even sparser spines on head; abdominal segments with many spines laterally but these absent medially from about segment VI anteriorly; intersegmental areas obscure on abdomen among spines; each spine mainly 25–35 ųm long, shortest anteriorly. Both size categories without short cone- or bollard-like spines associated with abdominal spiracles. Setae: (i) hairs significantly sunken into derm, each 20–25 ųm long: very sparse; (ii) hair-like setae not detected; (iii) minute setae of 2 types: setose setae about 3–5 ųm long, most common on head; more spinose setae up to 12 ųm long, most frequent near spiracles. Pores: (i) bilocular pores, each about 8 ųm long, 6–7 ųm wide, at base of a distinct tube 5–8 ųm deep: approximately equally abundant throughout, but on abdomen mainly in intersegmental membranes; and (ii) tubular pores, each 6–8 ųm long, 6–8 ųm wide (i.e. subequal to bilocular pores in width), tube 11–14 ųm deep; about equally abundant throughout and about 3–4 times more abundant than bilocular pores. Abdominal spiracles: large: outer atrium 30–35 ųm long, 23–25 ųm wide, each with 1 or 2 rows of pores at distal end; central atrium 25–27 long, 21–23 ųm wide; small: outer atrium 25–27 ųm long, 18 ųm wide, each with 1 or 2 rings of pores at distal end; central atrium 15 ųm long, 13 ųm wide, both sizes with smaller atrium at distal end, 8–10 ųm long. Anal area: (i) anal opening 95–100 ųm wide (large), 57–70 ųm wide (small); each with about 13–15 small pores around outer margin; (ii) band of tubercle-like pores about 4 or 5 pores deep (large) or 2 or 3 deep (small); outer diameter 157–170 ųm (large), 100– 125 ųm (small); (iii) with a narrow sclerotised rim in which a number of pale pores present (probably bollardlike spines) – clearer on large specimens and more obviously sclerotised; abdominal spiracles VIII lying laterad to outer rim, each spiracle without associated short cone- or bollard-like spines. Anal tube: (a) outer tube: large 190–200 ųm wide; small 125–140 ųm, and (b) finger-like extensions: large each about 170–200 ųm long, small each about 115–130 ųm long; distribution of pores on anal tube as in generic description.

Venter. Distribution of spines similar to that on dorsum, but marginal band perhaps narrower on abdomen, and spines absent from head. Pore and setal distribution similar. Antennae: large 26–32 ųm wide, small 20–22 ųm wide; each antenna without setae or small pores on derm near margin. Clypeolabral shield length: large 380 ųm, small 290–300, all facing laterally; labium: large about 145 ųm long, when present, facing anteriorly; small all missing. Thoracic spiracles: peritreme width: large 30–30 ųm wide, small 20–23 ųm wide, with 1 row of pores and a few more randomly distributed, totalling: large about 19–22 pores, small 12– 14 pores; length of muscle plate: large 105–130 ųm, small 65–80 ųm; each spiracle with 3–6 bollard-like spines on small and 10–11 spines on large specimens + 2–4 spinose setae.

Comment. The cysts of this species are characterised by the following combination of characters: (i) restriction of dermal spines more or less to abdomen; (ii) absence of short cone- or bollard-like spines around abdominal spiracles; (iii) small size of bilocular pores (approximately equal to width of tubular pores); (iv) bilocular pores sunken at end of a short but distinct tube; (v) structure of sclerotised area within anal complex, and (vi) the (more or less) single line of pores within the peritreme of each thoracic spiracle.

These are the cysts sent by Latta et al. (2001) to Douglass Miller (USNM) for identification when they were studying the feeding behaviour of birds on Stigmacoccus honeydew in Sierra de Bahoruco, Dominican Republic.

Figures

FIGURE 8. Cyst stage of Stigmacoccus species A, from Dominican Republic. For lettering, see Fig. 5.