Coccus circularis Morrison

Gullan, Penny J., Kondo, Takumasa, Fiala, Brigitte & Quek, Swee-Peck, 2018, Taxonomy of coccids (Hemiptera: Coccidae: Coccus L.) associated with Crematogaster ants (Hymenoptera: Formicidae) in the stems of Macaranga plants (Euphorbiaceae) in Southeast Asia, Zootaxa 4521 (1), pp. 1-51 : 14-18

Coccus circularis Morrison

urn:lsid:zoobank.org:act:DD61FCBF-DC4A-4EDD-818E-9E3875A97319

( Fig. 4 )

Coccus circularis Morrison, 1921: 665 .

Type material examined. Holotype: adult female, SINGAPORE: in hollow stems of Macaranga sp., date not given, coll. I.H. Burkill, Holotype 1(1) ( USNM). Paratypes: SINGAPORE: same data as holotype, 2(1 adult female + 1 first-instar nymph) ( USNM); in hollow stems of Macaranga triloba [now correctly named M. bancana ], date not given, coll. I.H. Burkill, 1396, 1(1) ( USNM).

Examined non-type material from original collection. SINGAPORE: in hollow stems of Macaranga griffithiana , date not given, coll. I.H. Burkill, 1389, 1(2 adult females + 2 nymphs) ( BMNH). These four BMNH specimens have similar data to the type collections listed above and one of the same Burkill collection numbers as provided by Morrison (1921) in his original description of this species, but they are not type specimens, as explained in the Materials and methods.

Other material examined: PENINSULAR MALAYSIA: Negeri Sembilan, Felda Pasoh , <100 m, ex M. hypoleuca , 18 Sept. 1999, coll. S.-P. Quek, SPQ.076, 1(1) . SINGAPORE: Lower Peirce Reservoir , <100 m, ex M. hypoleuca , 10 Oct. 1999, coll. S.-P. Quek, SPQ.094, 1(1) .

Other material examined. Coccus near circularis : BORNEO: Brunei, Batu Apoi Forest Reserve, 4° 33' N, 115° 09' E, 24 Aug. 1995, coll. P.J. Gullan, PJG-B47, 3(1 adult female & 13 first-instar nymphs); Sabah, Crocker Range, Keningau to Ulu Kimanis trail, 5.28° N, 116.05° E, 900 m, ex M. glandibracteolata , 19 Oct. 1999, coll. S.- P. Quek, SPQ.136a, DNA voucher 1(1); Sabah, Crocker Range, Tambunan to Kota Kinabalu Rd, 1000? m, ex M. puberula , 15 Oct. 1999, coll. S.-P. Quek, SPQ.098, DNA voucher 1(1); Sabah, Crocker Range, Tambunan to Kota

Kinabalu Rd, 1300 m, ex M. petanostyla , 24. Oct. 1999, coll. S.-P. Quek, SPQ.163, DNA voucher 1(1); Sabah, Poring, ex M. glandibracheolata , 17 Apr. 2001, coll. B. Fiala, #106, 6(6); Sabah, Poring Hot Springs, ex M. depressa , M. motleyana & M. petanostyla , no dates, coll. H.-P. Heckroth, #552, 573, 640, 1140 & 1410, 5(18) ( FRIM); Sabah, Poring Hot Springs, ex M. indistincta , no date, coll. H.-P. Heckroth, #589, 1(1 on slide with 1 adult female of C. pseudotumuliferus ) ( FRIM); Sabah, Ranau, roadside, ex M. beccariana , no date, coll. H.-P. Heckroth, #539, 1(3) ( FRIM).

Note. Specimens referred to as Coccus near circularis are all from Borneo and three of these specimens form Clade 4 in Quek et al. (2017, fig. 3). At our present state of knowledge, we consider these three specimens from the Crocker Range in Sabah (listed above) together with other specimens from Sabah and a specimen from Brunei, to be geographic variants of C. circularis (discussed below under Comments).

Adult female. Unmounted material. “Nearly to quite circular, dull grayish, appearing as if sprinkled with gray powder or dust; flat, but slightly ridged transversely about the middle and with low radiating ridges around the margin; anal cleft a little less than one-third the body length; extreme margin of body slightly elevated all the way around, forming a more or less distinct marginal ridge; ..” ( Morrison 1921: 665).

Slide-mounted adult female (n=6, based on adult females from Singapore, including all 5 collected by Burkill; Fig. 4 ). Body circular to oval, 3.0– 3.1 mm long, 2.6–3.1 mm wide.

Dorsum. Derm (dd) with numerous oval to circular areolations and with lightly sclerotised submarginal lines radiating inwards at right angles to margin. Dorsal setae (dset) slender, each with a flagellate apex, 15–30 µm long, scattered on dorsum. Simple pores (sp) each 2.5–3.0 µm wide, scattered evenly on dorsum. Preopercular pores (pop) each 4–6 µm wide, scarce (7 on holotype), present anterior to anal plates (not counted on most Singapore females but numbering 6–10 pores in non-Singapore females). Dorsal microducts (dmic) in areolations each about 2.0– 2.5 µm wide, appearing bilocular under high magnification. Anal plates (anplt) each triangular with anterolateral margin either equal to or slightly longer than posterolateral margin, length of each plate 1.5–1.8 times width, inner lobes well developed, with a tessellated texture, each plate 170–185 µm long, 100–145 µm wide, anterolateral margin 110–160 µm long, posterolateral margin 115–130 µm long; each plate with 4–7 dorsal setae [females from Sabah with 6–11 setae; see Comments], each seta 15–30 µm long. Anal ring (ar) bearing 10 setae, each 85–113 µm long.

Margin. Eyespots present on dorsal margin. Marginal setae (mset) in 1 row, each seta sharply spinose, with a pointed or bifurcate or fimbriate apex, 17–38 µm long. Marginal setae between anterior and posterior stigmatic areas on each side of body totalling 6–12 [females from Sabah with 19–27 setae; see Comments]. Stigmatic setae (stgset) well developed, spinose with pointed apices, numbering 3 per cleft, median setae usually longest, each 17– 40 µm long, lateral setae each 10–28 µm long.

Venter. Derm membranous. Ventral setae (vset) slender, prevulvar pairs longest, each 17–60 µm long, elsewhere shorter, each 10–23 µm long, with submarginal setae each 10–15 µm long. Interantennal setae in 2 or 3 pairs, each seta 10–25 µm long. Ventral tubular ducts (vtd) present in a broad submarginal band; each duct with outer ductule about 15 µm long, inner ductule 17–20 µm long, and duct opening about 2 µm wide. Ventral microducts (vmic) each about 2 µm wide, scattered fairly evenly on venter. Pregenital disc-pores (pgp) each with 5–8 (mostly 6 and 7) loculi, each pore 5–6 µm wide. Antennae (ant) each with 7, rarely 8, segments, 225–290 µm long; fleshy setae present on distal 3 segments. Clypeolabral shield 230–263 µm long, 230–255 µm wide; labium 90–100 µm long, 105–130 µm wide. Legs with hind trochanter + femur 165–185 µm long; hind tibia + tarsus 145– 190 µm long; all tarsal digitules each 26–33 µm long; claw digitules each 20–30 µm long, each claw 20–25 µm long. Spiracles normal: anterior peritremes each 52–55 µm wide; posterior peritremes each 57–70 µm wide. Spiracular pores (spp) each 4 µm wide, with 3–5 (mostly 5) loculi.

Comments. Adult females of C. circularis can be distinguished from all other species of Coccus known from Macaranga by having the combination of (i) slender dorsal setae each> 10 µm long and with a flagellate apex; (ii) marginal setae in a single row and with each seta spinose, 17–38 µm long and with a pointed, divided or fimbriate apex; and (iii) anal plates each with 4–7 setae, each seta ≤ 30 µm long. Adult females of C. circularis are most similar to the adult females of C. macarangae in having fewer than 10 setae on each anal plate and some or many marginal setae that are apically fimbriate or bifurcate, but differ from C. macarangae in that the dorsal setae are sparser, generally shorter (≤ 30 µm long) and more slender, and the preopercular pores are usually smaller (5–6 µm wide) and scarce (≤10) in C. circularis ( C. macarangae with some dorsal setae up to 40 µm long and 20–50 preopercular pores each 5–11 µm wide).

Burkill's collections of this species were from two Macaranga species from Singapore. No specific locality was provided on the labels but, during Burkill's time, collections may have been made at various places on the island because there would have been more native vegetation present. Heckroth et al. (1998) mentioned only a single specimen of this species and provided no further information on it. Only specimens from three collections from the Crocker Range in Sabah on Borneo were sequenced for the phylogenetic reconstruction of Quek et al. (2017, fig. 3, Clade 4). These three adult females, referred to as C. near circularis , are very similar morphologically to specimens from Singapore and one from Peninsular Malaysia, but have a greater number (19–27) of marginal setae between the anterior and posterior spiracular clefts on each side of the body compared with the Singaporean and Peninsular Malaysian specimens (5–12 setae), generally shorter marginal setae (12–25 µm long, but mostly 13–20 µm, versus 17– 38 µm long), shorter dorsal setae (10–15 µm versus 15–30 µm long) and often more dorsal setae on each anal plate (6–11 versus 4–7). The specimens from the Crocker Range were collected at higher altitude and are geographically separated from populations found in Singapore and Peninsular Malaysia. There are a number of other specimens from Sabah (from Poring Hot Springs and near Ranau) that seem to be C. near circularis , but most of the specimens are mature, damaged or heavily stained. The latter, however, appear similar to the three females from the Crocker Range, although their marginal setae appear shorter (generally 10–18 µm long). The single specimen from Brunei is also morphologically similar to the type specimens of C. circularis except that it has very few ventral tubular ducts on the head or the posterior abdomen. More samples are required for molecular analysis to determine the extent of any genetic variation among the regions.

Figures

FIGURE 4. Adult female of Coccus circularis Morrison. Abbreviations as in Fig. 3.