Platylecanium fusiforme Green

Hodgson, Chris, 2025, Revision of the soft scale genus Platylecanium (Hemiptera: Coccomorpha: Coccidae), with descriptions of eight new species, Zootaxa 5646 (2), pp. 151-198 : 174-176

Platylecanium fusiforme Green

Lecanium (Platylecanium) fusiforme Green, 1922: 1020 .

Lecanium fusiforme ; Green, 1937: 303. Subsequent use.

Platylecanium fusiforme ( Green, 1922) ; Takahashi 1942: 24. Change of combination.

Coccus fusiforme ( Green, 1922) ; Ali 1971: 24. Change of combination.

Platylecanium fusiforme ( Green, 1922) ; Tang 1991: 136. Revived combination.

Material examined

SRI LANKA: One slide with 3 specimens labelled: top label (circular): Type (in red); lower label: Lecanium / fusiforme / Green / Ambalangoda / Ceylon / III. 1911 (Lectotype (here designated) (1/3 adff, good. Lectotype specimen nearest Type label; other specimens here designated paralectotypes) ( NMHL). Two slides with a further 3 specimens, here designated paralectotypes, labelled: left label: Lecanium / fusiforme / Green / (type / material); right label: undet. plant / (? Memecylon sp. ) / CEYLON / Ambalangoda. / March 1911 / 4/78 ( NHML) (1/1 adf, mature specimen, good; 1/2 adff, immature, good).

Unmounted material. Not described by Green.

Slide-mounted adult female ( Fig. 9 ); description taken from all six specimens. Body basically lemon-shaped, rather pointed at both ends, length 2.4‒4.4 mm, width 1.25‒2.9 mm; anal cleft about 1/6 th of body length.

Dorsum. Derm membranous when very young, becoming variously sclerotised at maturity but palest near margin and in centre of each reticulation plate; sclerotised on older specimens mainly in a median line from anal plates to head and associated with reticulation lines. With 2 complete pale submarginal bands of areolations, those in more marginal band small; areolations in more submarginal band larger and more abundant. Reticulation plates mainly in 3 distinct longitudinal bands on each side, with a narrow additional band running from anal plates to anterior margin; marginal reticulation points reasonably distinct, with 13 on head between anterior stigmatic cleft and, on each side, 4 between stigmatic clefts and 13 on abdomen (latter including line close to anal cleft, often difficult to distinguish). With a distinct unsclerotised ray extending radially from each stigmatic cleft, each extending to dorsad to each spiracle or even a little further medially. Dorsal setae each 7‒9 μm long (subequal in length to a marginal seta), setose, mostly distinctly curved, each in a socket about 3‒4 μm wide; with only a few setae raised on a distinct fleshy base, each with seta on apex; setae restricted to within reticulation lines and more abundant towards margin, becoming distinctly scarce medially. Clear areas present as in diagnosis, each surrounded by a loose group of preopercular pores, each pore about 3‒4 μm wide (as wide as or wider than width of a setal basal socket), convex with a distinct border; preopercular pores approximately distributed as follows: (anteriormost) CA 1, 3‒15; CA 2, 4‒14; CA 3, 3‒13, CA 4, 5‒14. Dorsal pores possibly of 2 sizes, each represented by a clear area in derm on mature specimens, restricted to within reticulation lines along with dorsal setae; larger pores each about 2 μm wide (not easy to separate from preopercular pores), smaller pores, probably microducts, each 1‒2 μm wide. Anal plates much longer than broad, each 189‒202 μm long, combined width 118‒143 μm, each with anterior margin generally slightly shorter than posterior margin; each with 4 setae, each 5‒7 μm long, distributed as in diagnosis, and without small pores medially; underside of each plate showing nothing distinctive. Anterior margin of anogenital fold with 2 pairs of short fine setae; with 2 pairs of fine setae in middle of each lateral margin (often very difficult to see) and 1 short seta at posterior end of each apodeme; apodeme simple.

Margin. Margin not crenulated. Marginal setae all short, each about 7‒10 μm long (very similar to dorsal setae), and finely setose, each with a basal socket about 3 μm wide; with 1‒3 (rarely 4) setae approximately associated with each marginal reticulation point; with about 23 setae between anterior stigmatic clefts and, on each side, 9 setae between stigmatic clefts, and 21‒23 along abdominal margin. Stigmatic clefts quite deep, each with outer margins touching or almost so; inner part of cleft quite broad, with inner margin strongly sclerotised; each containing 3 stigmatic spines subequal in length, each 40‒60 μm long; each outer cleft margin with 2 or 3 marginal setae. Anal cleft with margins touching. Eyespots each more-or-less round, located on dorsum away from margin, width of lens about 20‒25 μm.

Venter. Multilocular disc-pores each 7‒8 μm wide, mostly with 10 loculi, frequent on either side of genital opening and on preceding segment only; number on each side: VII, 13‒22; VI, 9‒23. Spiracular disc-pores, each about 3.0‒3.5 μm wide, mostly with 5 loculi, present in a narrow band between each spiracle and margin; with 15‒27 pores in each anterior band and 20‒38 in each posterior band. Ventral microducts minute, rather sparsely distributed throughout. Ventral setae: interantennal setae short and sparse; with pairs of long setae present on abdominal segments VII, each 66‒90 μm long, and VI, each 25‒40 μm long; setae sparse elsewhere, smaller submarginally than medially. Antennae very reduced, but each possibly with 4 or 5 obscure segments, with setae only visible on near apex; total antennal length 53‒75 μm. Clypeolabral shield 120‒126 μm long; clypeal setae absent. Spiracles small, width of each peritreme 33‒40 μm. Legs very small to minute, more-or-less reduced to a claw; metathoracic legs longest, each 13‒23 μm long, prothoracic legs each 5‒12 μm long; digitules absent.

Comments. Platylecanium fusiforme can be diagnosed by the following combination of character-states: (i) body lemon shaped, mature adults distinctly pointed at each end; (ii) anal plates clearly longer than their combined width; (iii) each anal plate without a cleft on underside of inner margin; (iv) margin not crenulated; (v) marginal and dorsal setae similar in size; (vi) preopercular pores similar in width to width of a setal socket; (vii) preopercular pores associated with all four clear areas; (viii) each stigmatic cleft with 3 stigmatic spines, subequal in length; (ix) multilocular disc-pores restricted to abdominal segments VII and VI; (x) legs very reduced, mainly to a claw, without digitules, and (xi) antennae moderately developed, showing 4 or 5 obscure segments. The dorsum of mature P. fusiforme becomes sclerotised along the reticulation lines, somewhat similar to mature P. nepalense , but the latter has (i) many more stigmatic spines in each cleft; (ii) shorter antennae, and (iii) the body is much less pointed at each end.

In having: (i) moderately developed antennae, much longer than 3 times basal width; (ii) multilocular disc-pores restricted to abdominal segments VII and VI, and (iii) marginal setae more-or-less restricted to marginal reticulation points, P. fusiforme somewhat resembles P. coelogyne , described as new above, but differs in having: (i) a body with pointed anterior and posterior ends; (ii) much longer anal plates, and (iii) long thin stigmatic spines.

Platylecanium fusiforme has only been recorded from Sri Lanka and does not appear to have been collected since the original description ( García Morales et al. 2016). The possible host, Memecylon sp. , belongs to the Melastomataceae , a large family with 194 genera of mostly tropical shrubs and herbs ( Brummitt 1992).

Figures

FIGURE 9. Platylecanium fusiforme Green, adult female.