Paralecanium (Hodgson & Williams, 2018)

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 : 153-155

Key for separation of genera close to Paralecanium , based on the morphology of the adult female (defined here as those genera with pairs of clear areas on the abdomen).

1. Stigmatic spines in each cleft in an elongate group of 5 or more extending radially onto dorsum. Preopercular pores present in groups submarginally on dorsum, each group fused to form a compound pore........ Insularicoccus Hodgson & Williams.

- Stigmatic spines in each cleft in a line along inner margin of cleft, not in an elongate group extending radially onto dorsum. Preopercular pores, if present, not fused but forming loose groups around each abdominal clear area................... 2

2. Pale rays arising from each stigmatic cleft absent. Each margin between stigmatic clefts with 3 reticulation points, each point indicated by distribution of dorsal setae and pores. Preopercular pores absent. Legs well developed. Paralecanium Cockerell.

- Pale rays arising from each stigmatic cleft generally present. Each margin between stigmatic clefts with 4 or 5 reticulation points, each point indicated by distribution of dorsal setae and pores. Preopercular pores present. Legs either absent or represented by leg stubs (rarely more developed)........................................................................ 3

3. Marginal setae fan-shaped, rather abundant and evenly distributed around margin. Usually with 5 marginal reticulation points laterally between stigmatic clefts............................................. Discochiton Hodgson & Williams.

- Marginal setae finely setose, generally rather sparse and usually clearly concentrated in loose groups near each reticulation point. Usually with 4 marginal reticulation points laterally between stigmatic clefts... Platylecanium Cockerell & Robinson.

PLATYLECANIUM Cockerell & Robinson, 1915

Platylecanium Cockerell & Robinson, 1915a: 427 .

Platilecanium Danzig & Konstantinova, 1990: 44. Misspelling of genus name.

Platylecarium Tang, 1991: 135 , misspelling of genus name.

Type species: Platylecanium cribrigerum Cockerell & Robinson , by original designation.

Generic diagnosis. (Features in italics of particular taxonomic significance). Belonging to the family Coccidae . Body sometimes asymmetrical; usually flat; membranous when young but becoming sclerotised at maturity; in life, probably covered in a thin glassy/waxy test.Anal cleft usually about 1/6 th ‒1/7 th of body length. Dorsum with a sparse reticulate pattern of pores and setae, these lines of pores and setae most obvious near margin; lines extending from margin and forming reticulation plates; generally with 3 or 4 longitudinal bands of reticulation plates on each side (though this can be hard to determine due to paucity of setae and pores medially). With a ray of unsclerotised derm extending radially from each stigmatic cleft (not visible on non-mature specimens). Dorsum with various patterns of dermal ornamentation, including areolations, particularly submarginally. Eye spots displaced to medially on dorsum almost dorsad to scape ( Fig. 1E ). Dorsal setae usually shorter than marginal setae and each often raised on a membranous mound. With 4 (rarely 5) pairs of clear areas on abdomen, each usually with associated preopercular pores. Dorsal tubercles, pocket-like sclerotisations and tubular ducts absent. Anal plates together quadrate, with 4 fine setae near the apex: 2 near inner margin, 1 on apex and 1 near posterior margin. Anal cleft usually with 1 or 2 pairs of small setae along anterior margin and 1‒4 pairs on each lateral margin. Anal ring with 6 setae, ventral anal ring setae largest and longest. Margin with or without ornamentation, when present in the form of crenulations. Marginal setae finely setose and generally rather sparse, mainly positioned in groups at each reticulation point; often also present along outer margins of each stigmatic cleft. Stigmatic clefts quite deep, each with a narrow entrance and sides almost touching, and with innermost margins of cleft heavily sclerotised; each cleft usually with 3 stigmatic setae but more present in some species. Venter. Ventral tubular ducts absent. Preantennal pores absent. Multilocular disc-pores usually with 10 or 11 loculi, restricted to abdominal segments VI and VII only or V, VI and VII. Spiracular disc-pores small, mainly with 5 loculi, usually present in narrow bands 1 or 2 pores wide. Ventral microducts small to minute. Antennae usually greatly reduced but occasionally with up to six segments visible. Clypeolabral shield typical of Coccidae but clypeal setae absent. Spiracles small. Legs either absent or represented by little more than claws without digitules.

Key to Platylecanium species, based on adult female morphology

1. Each stigmatic cleft with 4 or more stigmatic spines......................................................... 2

- Each stigmatic cleft with 3 stigmatic spines (rarely 4 in one or two clefts).. ....................................... 3

2. Mature adult small (<4.3 mm long). Antennae fairly short, not obviously 4 or 5 segmented. Anal plates less than 210 μm long. On Orchidaceae ................................................................ P. vanda Hodgson spec. nov.

- Mature adult larger (> 4.2 mm long). Antennae each clearly 4 or 5 segmented. Anal plates more than 240 μm long. On nonorchidaceous hosts, mainly Arecaceae ..................................................... P. nepalense Takagi

3. Antennae each clearly with 3 or more segments, total length more than 3 times width of scape (= segment I)............ 4

- Antennae very reduced, each consisting of a narrow basal scape and another ‘segment’, total length generally less than 3 times longer than width of scape.............................................................................. 6

4. Multilocular disc-pores present in venter of abdominal segments V, VI and VII. Marginal setae evenly distributed around margin....................................................................... P. palmae Hodgson , sp. nov.

- Multilocular disc-pores only present in venter of abdominal segments VI and VII. Marginal setae distributed unevenly, tending to form groups of 1‒4 at end of each marginal reticulation point................................................ 5

5. Stigmatic spines short and thick. Anal plates together quadrate, about as long as their combined widths. Body rounded at both ends ....................................................................... P. coelogyne Hodgson , sp. nov.

- Stigmatic spines long and relatively narrow. Anal plates much longer than their combined widths. Body lemon-shaped, somewhat pointed at both ends............................................................ P. fusiforme Green

6. Underside of each anal plate with a deep cleft on inner margin (arrowed in Figs 1 & 2 ); also with a seta displaced from lateral margin of anal cleft (arrowed in Figs 1 & 2 )........................................... P. asymmetricum Morrison

- Underside of each anal plate without a deep cleft on inner margin, and lacking an additional seta near lateral margin of anal cleft................................................................................................... 7

7. Body elongate, length clearly more than twice width......................................................... 8

- Body relatively broad, length less than twice width......................................................... 12

8. Anal plates subequal in length to their combined widths; each plate with anterior margin as long as or longer than posterior margin............................................................................................. 9

- Anal plates significantly longer than their combined widths; each plate with posterior margin clearly longer than anterior margin............................................................................................ 10

9. Margin not crenulated. Dorsum with areolations present submarginally....................... P. riouwense Takahashi *

- Margin crenulated. Dorsal submargin without areolations............................... P. eastopi Hodgson , sp. nov.

10. Dorsum without areolations. Stigmatic spines subequal in length or with median spine shortest. Stigmatic spines not reaching to margin........................................................................ P. elongatum Takahashi *

- Dorsum with distinct areolations. Stigmatic spines long; spines may be subequal in length but median spines never shortest. Stigmatic spines may or may not reach to margin........................................................... 11

11. Dorsal areolations very obvious, forming a broad submarginal band. Marginal setae frequent, forming groups of 1‒3 (mainly 2) per marginal reticulation point. Stigmatic spines not reaching margin. Body rounded at both ends... .. P. cyperi Takahashi

- Dorsal areolations not very obvious, not forming a broad submarginal band. Marginal setae few, with rarely more than 1 per marginal reticulation point. Stigmatic spines long, with median spines reaching to margin. Body somewhat pointed at both ends........................................................................... P. dendrobii Hodgson , sp. nov.

12. Anal plates subequal in length to their combined widths, length of single plate no more than twice as long as width, with apex not acute........................................................................................... 13

- Anal plates much longer than broad, length of single plate about 3 times as long as width, with apex acute............. 14

13. Multilocular disc-pores each with only 6 or 7 loculi. Preopercular pores large and abundant, associated with all clear areas. Dorsal setae blunt or even capitate. .............................................. P. faveolatum Hodgson , sp. nov.

- Multilocular disc-pores each with mainly 10 loculi. Preopercular pores small and few, associated mainly with posterior clear areas, but rare or absent from anterior clear areas. Dorsal setae finely setose........ P. cribrigerum (Cockerell & Robinson)

14. Anal plate apodemes fused at anterior end of anal cleft..................................... ... P. mesuae Takahashi

- Anal plate apodemes completely separate, not nearly meeting at anterior end of anal cleft.......................... 15

15. Margin not crenulated. ................................................................... P. citri Takahashi *

- Margin crenulated. ................................................................................... 16

16. With 4 pairs of clear areas on abdomen and none elsewhere. Anal plates each 176‒244 μm long, 134‒164 μm combined width...................................................................... ... P. sarawakense Hodgson , sp. nov.

- With 5 pairs of clear areas on abdomen and an additional pair at inner end of each anterior stigmatic ray. Anal plates each 150‒153 μm long, combined width about 118 μm. .................................. P. watsoniae Hodgson , sp. nov.

Figures

FIGURE 1. Platylecanium asymmetricum Morrison, adult female (paratype female, Singapore). Where A= a clear area; C = crenulations; E = eyepost; L = a reticulation line between reticulation plates; M = a marginal reticulation point, where a reticulation line reaches the margin, and P = a reticulation plate, the margins of which are indicated by reticulation lines.

FIGURE 2. Platylecanium asymmetricum Morrison, adult female (Pl. cocotis Laing, paralectotype, from Vanuatu).