Paralecanium ovatum Morrison

Chris J. Hodgson & Douglas J. Williams, 2018, Revision of the soft scale genus Paralecanium (Hemiptera: Coccomorpha: Coccidae) with the introduction of three new genera and twenty new species, Zootaxa 4443 (1), pp. 1-162 : 124-126

Paralecanium ovatum Morrison

( Fig. 52 )

Paralecanium ovatum Morrison, 1921 , 671. Type data: SINGAPORE: Botanic Gardens, on Pandanus sp. Syntypes, female, male, and first instar. Type depository USNM.

Material examined. Holotype and paratype ff: SINGAPORE: left label: Paralecanium / n. sp. vacuum / Singapore / C.F. Baker / Oct. 1917 / #9029 (USNM): 1/4adff (f; all venters damaged and legs very hard to see; specific name, vacuum written in pencil; holotype and paratypes ff written on envelope; bottom right-hand specimen marked as holotype). Paratypes: Paralecanium / ovatum / on Pandanus / Singapore / C.F. Baker / Oct. 1917 / #9029 (USNM): 1 slide with 2 first-instar nymphs (p) and a second/third-instar female nymph (f). Left label: Paralecanium / ovatum / on Pandanus / Singapore / C.F. Baker / Oct. 1917 # 9029 (BMNH): 1/1adf (f-p, missing much of venter and quite heavily sclerotised. Presumably a paratype female). Paralecanium / ovatum / on Pandanus / Singapore / C.F. Baker / Oct. 1917 / # 9029 (USNM): 2/3?adff – envelope states both paratypes.

Other material. Two slides labelled Paralecanium nr. peradeniyense , intercepted in ENGLAND, (Cornwall, glasshouse), ex? Malaysia, via Holland on Chrytostachys [= Cyrtostachys ] renda palm leaves, 29.x.2004, K. Treseder ( BMNH): 2/8adff (g).

Note. The description is based on all specimens in the type series.

Slide-mounted adult female. Body broadest posteriorly and more pointed anteriorly. Length 2.0– 2.5 mm, width 1.3–1.5 mm.

Dorsum. Derm of mature specimens rather uniformly sclerotised; submarginal areolations tending to be somewhat elongate and to lie with their axes radially but becoming rounder submedially and absent more medially; derm with sparse minute pale spots throughout, each about 0.5 µm wide. Marginal radial lines membranous, long and distinct, with some dividing and others coalescing, as follows: with 11 on head, each side with 3 between stigmatic clefts and 11 on abdomen but none from each cleft. With 4 pairs of abdominal clear areas and a pair also present on prothorax. Dorsal setae each short and slightly clubbed, each 5–7 µm long, most frequent in a submarginal band, probably in a sparse polygonal pattern; absent medially. Large dorsal pores, each 3–4 µm wide without clear micropores, present in a broad submedial band of about 18–25 on each side extending anterolaterally from anal plates to head. Simple pores, each in a clear spot about 1.5 µm wide, sparse throughout but absent medially, mainly appearing to be indistinguishable from setal basal sockets. Anal plates together quadrate, each with a slightly rounded outer angle, and with anterior margin subequal to posterior margin; posterior margin slightly serrated near apex (this is usually also true of posterior margin of anal plate orifice); with probably at least 2 setae near apex of each plate; also with 1 or 2 small pores medially; length of plates 115–125 µm, combined width 90–100 µm. Anogenital fold with 1 pair of small setae along anterior margin, each lateral margin with 1 seta anteriorly and another posteriorly.

Margin. Margin with shallow castellations, each without short radial lines or ridges; with usually 2 or 3 castellations between marginal setae; also with each marginal seta on a raised area of derm. Marginal setae fanshaped and oval; width of each fan 30–35 µm, length 20–25 µm; with 76–92 setae anteriorly between anterior stigmatic clefts, each side with 33–36 between stigmatic clefts, and 78–89 along abdominal margin. Stigmatic clefts quite deep, each with a sclerotised inner margin and 3 stigmatic spines, each spine parallel-sided or slightly clavate; median spine slightly longer than lateral spines; length of each median spine 25–35 µm; lateral spines each 18–24 µm long. Eyespots each more or less round; width of socket 60–65 µm, diameter of lens about 18–22 µm.

Venter. With a broad dark border about 65–120 µm wide with darker radial “fingers” (absent on young specimens). Multilocular disc-pores abundant around genital opening and in preceding 2 or 3 segments, each side with 10–17 in abdominal segment VII, 13–24 in segment VI and 0–4 in segment V. Spiracular disc-pores present in a narrow band between margin and each spiracle, with 13–17 pores in each band. Ventral microducts not detected. Ventral setae: with 2 pairs of interantennal setae; long preanal setae medially on abdominal segment VII, each 60– 70 µm long, and shorter setae in segments VI–II; without longer setae laterad to posterior ends of anal plates; submarginal setae few and short; other setae sparse. Antennae reduced and some misshapen, each with 6 segments; total length 120–150 µm; length of apical segment about 25 µm; length of apical seta about 16 µm; setal distribution typical of family except no setose setae in segments IV and V. Clypeolabral shield about 100–105 µm long. Spiracles quite small, width of each peritreme 25–28 µm. Legs much reduced in size, without trochanterofemoral or tibio-tarsal segmentation; dimensions of hind leg (µm): coxa about 16, trochanter + femur 26–35, tibia + tarsus 28–35; claw 4. Tarsal digitules short, subequal to or shorter than claw digitules with small capitate apices; claw digitules with one slightly longer than other with a broader apex; claw very small, probably without a denticle. Setal distribution: coxa 2; trochanter 0 or 1 (short); femur 0 or 1; tibia + tarsus 0–3.

Comments. In having reduced legs, adult female P. ovatum are similar to those of P. neoguineense Hodgson spec. n. —see under that species above for a comparison. Of the Paralecanium species that have distinct membranous radial lines extending medially from the margin and broad submedial bands of large dorsal pores, the small size of the legs makes identification of these two species easy.

The specimen identified by Williams and Watson (1990, 134) as P. ovatum from Papua New Guinea is almost certainly from the type series of P. neoguineense , described as new above.

Host-plants. Pandanus sp. (Pandanacaeae); Cyrtostachys renda (Arecaceae) .

Figures

FIGURE 52. Paralecanium ovatum Morrison, adult female.