Paralecanium marginatum (Green)

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 : 111-112

Paralecanium marginatum (Green)

( Fig. 46 )

Lecanium marginatum Green, 1896 , 9. Type data: SRI LANKA: Punduloya, on Psychotria thwaitesii . Syntypes, female. Type depository: BMNH, London, England, U.K.

Lecanium marginatum ; Cockerell & Parrott, 1899, 227.

Paralecanium marginatum ; Fernald, 1903, 199. Change of combination.

Material examined. Lectotype f (here designated): SRI LANKA (as Ceylon): top labels: TYPE in red on round label + Lectotype in red on narrow label; bottom label: Lecanium / ( Paralecanium ) / marginatum / Green / from /

Psychotria thwaitesii / Pundaluoya / Ceylon ( BMNH): 1/2adff (g; lectotype bottom specimen, clearly marked). Envelope indicates that E.E.G. was collector.

Other material. SRI LANKA: a slide, broken in half but with 1 possibly reasonable specimen, with same data as above ( BMNH), and therefore a paratype specimen, plus another slide with a second-instar male ( BMNH) (p).

BRUNEI, Temburong Distr., ridge NE of Kuala Belalong , approx. 300m alt, on unknown host ( Theaceae ?), 30.x.1992, J.H. Martin #6190 ( BMNH): 1/1adf (fg).

Note. The description is based on both of the type specimens.

Unmounted material. “Pale fulvous to castaneous, a sub-marginal zone almost colourless. Oval, pointed in front.” “On upper surface of leaves of Psychotria thwaitesii . ” ( Green 1896, p. 9).

Slide-mounted adult female. Body broadest across abdomen and more pointed anteriorly. Length 2.0– 2.2 mm, width 1.4–1.5 mm.

Dorsum. Derm rather uniformly sclerotised, without areolations; most of derm appearing to have a rather convoluted structure; without a medial longitudinal darker area. Marginal radial lines absent but indicated by position of dorsal setae, with perhaps 11 lines anteriorly between anterior stigmatic clefts, 1 from each stigmatic cleft, each side with 3 between clefts and 11 on abdomen. Abdominal and thoracic clear areas absent. Dorsal setae of one size, small, each 7–10 µm long, probably with a fairly sharp apex; apparently restricted to within marginal radial lines but with only 1 in each line, almost all within area of ventral marginal band; apparently absent medially. Dorsal pores of possibly 2 sizes present but these not easy to differentiate, large pores appearing as a round clear spot about 2.5 µm wide, with a pore medially, each pore about 1.5–2.0 µm wide; sparsely distributed in a submedial band, with about 20 on each side; smaller pores, probably microducts, not as round and often appearing elongate, each about 1.5 µm wide, more abundant but still sparse in an apparently polygonal pattern. Anal plates together approximately quadrate; each plate with 3 small setae near apex: 1 near outer margin and 2 along inner margin (presence of apical seta unknown); each plate also with a single small pore medially; length of plates about 125 µm, combined width about 90 µm. Anogenital fold with 2 or 3 small setae on each side of anterior margin, each lateral margin with 1 small seta about half-way along and another posteriorly.

Margin. Marginal ornamentation present as distinct, quite strong castellations, with usually 4–6 between marginal setae. Marginal setae oval and fan-like; width of each fan 33–40 µm, length 23–26 µm; with 48 or 49 setae on head between anterior stigmatic clefts, each side with 16–19 between stigmatic clefts, and 4 4–49 along abdominal margin. Stigmatic clefts narrow and quite deep, each with a lightly sclerotised inner margin and 3 spines, median spine longest but none with apex extending out of cavity; length of each median spine 40–47 µm, laterals each 28–33 µm. Eyespots oval: width of socket about 40 µm, diameter of lens about 17 µm.

Venter. A broad darker band present marginally, 190–225 µm wide with darker radial finger-like markings. Multilocular disc-pores in groups on either side of genital opening and on preceding two segments, each side with possibly 5–8 on abdominal segment VII, 9–14 on segment VI and 8–10 on segment V. Spiracular disc-pores present in a narrow band mainly 1 pore wide between margin and each spiracle, with 12–22 in each band. Ventral microducts present but scarce. Ventral setae: with 2 pairs of interantennal setae; preanal setae in abdominal segment VII each 90 µm long; pairs of long setae present medially in all abdominal and thoracic segments but absent laterad to anterior end of anal cleft. Antennae well developed, each with 6 segments; total length about 220 µm; apical segment 45–50 µm long; apical seta short, each 20–24 µm long. Clypeolabral shield small, about 85–95 µm long. Spiracles: width of each peritreme 17–20 µm. Legs well developed; trochanterofemoral segmentation indistinct; dimensions of hind leg (µm): coxa 73–75, trochanter + femur 108–110, tibia 60–70, tarsus 60–63; claw 11. Tarsal digitules slightly longer than claw digitules, with capitate apices; claw digitules both capitate but one clearly narrower than other; claw without a denticle.

Comments. The presence of several multilocular disc-pores in abdominal segment V separates P. marginatum from most other similar species. In addition, this species has: (i) crenulated marginal ornamentation and (ii) setose dorsal setae.

Host-plants. Psychotria thwaitesii (Rubiaceae) ; Theaceae ?

Figures

FIGURE 46. Paralecanium marginatum (Green), adult female.