Paralecanium geometricum (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: 97-99

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Paralecanium geometricum (Green)


Paralecanium geometricum (Green) 

( Fig. 39 View Figure )

Lecanium geometricum Green, 1896  , 9. Type data: SRI LANKA: Pundaluoya, on undetermined shrub. Syntypes, female. Type depository: BMNH, London , U.K. 

Lecanium geometricum  ; Cockerell & Parrott, 1899, 227.

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

Lecanium limbatum Green, 1922  , 1023. Type data: SRIAbout SRI LANKA, Batticaloa, on Ixora coccinea  . Syntypes, female. Type depository: BMNH, London, England, U.K. Syn. n.

Paralecanium limbatum  ; Green 1937, 306. Change of combination.

Material examined. Lectotype f and paralectotype ff (here designated): SRIAbout SRI LANKA (as Ceylon): top labels: TYPE in red on round label + Lectotype in red on narrow label; Lecanium  / geometricum  / Green / from / Glycosmis  / pentaphylla  / Pundaluoya / Ceylon ( BMNH): 1/3adff (fg; mature females; most legs and antennae damaged or missing. Lectotype middle specimen, clearly marked. Envelope indicates E.E.G. as collector). Labelled Syntype, Sri Lanka (as Ceylon): top labels: CO-TYPE on oval label; Lecanium  / ( Paralecanium  ) / geometricum  / Green / from / Glycosmis pentaphylla  / Pundaluoya / Ceylon ( BMNH): 1/5adff (fg; mature females, most missing some or all venter).

Lecanium (Paralecanium) limbatum Green.  Lectotype f and paralectotype f (here designated): SRIAbout SRI LANKA (as Ceylon): top labels: TYPE in red on round label + lectotype in red on narrow label; bottom label: Lecanium  / ( Paralecanium  ) / limbatus Green / from Ixora  / Batticaloa / Ceylon May 0 6 ( BMNH): 1/2adff (f-p; one old female (designated lectotype) and one young adult lacking most of venter. Collector as E.E.G. on envelope).

Other material. Paralecanium geometricum  : SRI LANKA (as Ceylon), Pundaluoya, on Glycosinis (should be Glycosmis  ) pentaphylla  , probably mounted from dried material of E.E. Green (BMNH): 5/5adff (f-p, most missing some or all venter). Sri Lanka (as Ceylon), Pundaluoya, on?host, no coll. [E.E.G. on envelope] (BMNH): 2/3adff (f-p, most missing some or all venter). Sri Lanka, as Ceylon, Namunakuli [probably Namunukula], no host or collector, -. ii.1910 (BMNH): 1/4adff (f-g). Sri Lanka, as Ceylon, Pundaluoya, no host or coll. [E.E.G. on envelope] (BMNH): 2/4adff (mainly g; possibly part of type series). Sri Lanka, as Ceylon, Kesbewa, on Ixora  sp., April 1903, no coll. [E.E.G. on envelope] (BMNH): 1/1adf (p, venter damaged, identified as Lecanium geometricum Green  – note that this is the same host-plant genus as for the type of P. limbatum Green  ). Sri Lanka (as Ceylon): Peradeniya, no host or coll. (E.E.G. on envelope] (BMNH): 1/2adff (1 g, 1 p).

MALAYSIA, Malaysia (west), Pahang Prov., Kuantan, Hutan Lipur Tolek Cempedak, on Ardisia kunstleri, Jul.  –Aug., 1990, S. Takagi 90ML-329 ( BMNH): 1/1adf (f).

Note. The description is based on a selection of type specimens of P. geometricum  off Glycosmis  from Pundaluoya and both specimens of P. limbatum  (data for the latter are given in [...] brackets where different).

Unmounted material. Of P. geometricum  : ‘Pale castaneous, or fulvous. Flattish, sub-round, median dorsal area with concentric series of polygonal depressed spaces.’ ( Green 1896, p. 9). Of P. limbatum  : “Adult female broadly ovate; flat. Colour bright castaneous, the marginal area and median-longitudinal fascia darker. Dorsum with five or six inconspicuous hyaline streaks, on each side, extending inwards from the margin. Venter with a sharply defined, broad, denser marginal zone.” “Length 3 mm ”. “On Ixora coccinea, Batticaloa.  ” ( Green, 1922, p. 1023).

Slide-mounted adult female. Body broadly oval. Length 3.1–3.4 [2.9] mm, width 2.1–2.6 [2.2] mm.

Dorsum. Derm of young adult rather uniformly sclerotised, mature specimens uniformly sclerotised but with a broad, more heavily sclerotised, area medially [unsclerotised]; with pale areolations throughout dorsum but those submarginally and submedially more uniformly distributed than marginally; rest of derm with abundant minute pale spots. Marginal radial lines only indicated by distribution of dorsal pores and setae, with 11 anteriorly between stigmatic clefts, each side with 3 between stigmatic clefts and probably 10 or 11 on abdomen; also with lines of slightly paler derm or dermal folds present (although sometimes indistinct, particularly on head), with 2 lines anteriorly between anterior stigmatic clefts, a line from each cleft, each side with 1 line between clefts and 4 on abdomen. Abdominal clear areas small, with 4 or 5 on each side on abdomen plus another at end of radial line from anterior stigmatic cleft. Dorsal setae short and more or less parallel-sided with a blunt apex, each 5–6 µm long, sparse, apparently restricted to submargin; absent medially. Dorsal pores of possibly 2 sizes: (i) pores with a dark centre, each about 2 µm wide, and (ii) rather similar but slightly smaller simple pores, each 1.5–2.0 µm wide; pores present in a distinct, sparse polygonal pattern and in about 7 or 8 transverse lines medially. Anal plates together elongate, each with a squarish outer margin; each plate with perhaps 2 small setae near apex and with 2–5 small pores medially; plates 200–215 [195–200] µm long, combined width 115–125 [125–130] µm. Anogenital fold with 2 (occasionally 3) pairs of small setae along anterior margin and 3 pairs of small setae along lateral margins.

Margin. Marginal ornamentation present in the form of quite deep corrugations, sometimes with short radial lines. Marginal setae fan-shaped and more or less round; width of each fan mostly 35–40 µm, length 26–35 µm; with about 87–90 [74] setae anteriorly between anterior stigmatic clefts, each side with 31–38 [29–31] setae between stigmatic clefts, and 74–82 [72 or 73] along abdominal margin. Stigmatic clefts quite deep, each with a sclerotised inner margin and 3 rather parallel-sided stigmatic spines, subequal in length, each 48–55 [33–46] µm long. Eyespots each oval; width of socket 50–58 µm and of lens 18–20 [21] µm.

Venter. Mature specimens with a broad dark marginal band about 270 µm wide, with numerous short dark radial fingers. Multilocular disc-pores present in groups on either side of genital opening and on preceding segment only, each side with 19 or 20 on abdominal segment VII and 32–35 [30] on segment VI. Spiracular disc-pores present in a narrow band between margin and each spiracle, with 18–34 pores in each band. Ventral microducts apparently sparse, only detected submarginally. Ventral setae: 2 pairs of interantennal setae present; longer setae present on abdominal segments VII, VI and V and mesad to each coxa; no group of long setae present at anterior end of anal cleft but with 2 or 3 short setae in this position. Antennae well developed, each with 6 segments; total length 220–240 µm; apical segment about 55 µm long; apical seta short, each 20 [22] µm long; setal distribution normal. Clypeolabral shield about 95–105 µm long. Spiracles small, width of anterior peritremes 23–25 [24–27] µm, posterior peritremes 26–30 µm. Legs well developed, often with tibio-tarsal articulation obscure; dimensions of prothoracic legs (µm): coxa 65–68 [60], trochanter + femur 90–92 [86], tibia 50–56 [46–48] and tarsus 42 [50– 58]; claw 10 µm. Tarsal digitules slightly longer than claw digitules, with capitate apices; claw digitules both broad but one possibly narrower than other; claw without a denticle; setal distribution: coxa 6; trochanter 1, rather short; femur 2; tibia 2 and tarsus 3.

Comments. The data given above for P. geometricum  and P. limbatum  are almost identical; indeed, there is a slide identified previously (by Green?) as P. geometricum  that had been collected off Ixora  sp., the host of P. limbatum  . Therefore, the name P. limbatum  is here made a junior synonym of P. geometricum  , syn. n.

Adult female P. geometricum  are somewhat similar to those of P. hainanense  , P. machili  , P. marginatum  and P. morobeense  (described as new below), all of which have rather small dorsal pores. For main differences, see key.

Host-plants. Glycosmis pentaphylla  ( Rutaceae  ); Ixora coccinea  ( Rubiaceae  ), Ardisia kunstleri  ( Myrsinaceae  ). Unconfirmed plant hosts: Laurus novocanariensis  ( Lauraceae  ).


Serengetti Research Institute














Paralecanium geometricum (Green)

Chris J. Hodgson & Douglas J. Williams 2018


Lecanium limbatum

Green 1922


Lecanium geometricum

Green 1896


Lecanium geometricum

Green 1896