Discochiton paucipedis Hodgson

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 : 54-56

Discochiton paucipedis Hodgson spec. n.

( Fig. 19 )

Material examined. Holotype f and paratype f: INDIA: top label: Discochiton / paucipedis / Hodgson / Holotype / and paratype ff; bottom label: Paralecanium / expansum / Green / on Calophyllum / Nellikuppam, S. Arcoth / India / coll. Ramakrishna #152 (BMNH): 1/2adff (fg, but holotype specimen split into anterior and posterior halves; paratype specimen central, without a venter; labelled Paralecanium expansum Green ). Paratype ff: India: top label: Discochiton / paucipedis / Hodgson / Paratype ff; bottom label: Lecanium / ( Paralecanium ) / expansum, Green / from Calophyllum, / Puri, Orissa, India / ex.coll. Ind. Mus. / # 50 (BMNH): 1/2adff (fp, poorly cleared).

Other material. INDIA: South India, Coimbatore, Ponnuthu, host indet., 18.i.1953, T.S. Mutherkrishnan, Agric. Res. Inst., Coimbatore, ref 11 ( BMNH, BM 1958 – 578): 1/1adf (fg; labelled Paralecanium expansum Green ).

Note. The description is based on all type specimens; data from non-type specimen from Ponnuthu in […] brackets.

Slide-mounted adult female. Body almost round. Length 4.0–6.0 [6.4] mm, width 4.2–5.6 [6.2] mm.

Dorsum. Derm rather uniformly sclerotised, with a fairly broad band of elongate areolations close to margin, long axis of each areolation running parallel with margin; inner submargin with small oval areolations, these becoming more distinct submarginally and submedially; rest of derm with abundant minute pale spots, and specimens from Nellikuppam with dorsal pores forming 4 longitudinal rows of polygons on each side. Stigmatic rays present; marginal radial lines obscure, indicated by distribution of pores and setae, with 13 on head between anterior stigmatic clefts, each side with 5 between stigmatic clefts and 11–13 on abdomen. With 5 [4] pairs of abdominal clear areas plus another at apices of anterior stigmatic rays. Dorsal setae each spinose, with parallel sides and often a slightly capitate apex, each 11–13 [10–12] µm long, longest medially, each with a broad basal socket about 5 µm wide, frequent in a sparse polygonal pattern; frequency rather variable but setae absent or sparser medially; many dorsal setae each closely associated with a broad membranous area about 8 µm wide (some of these areas lack a seta but it is considered that the setae have been lost). Preopercular pores each convex, 3–4 µm wide, with 1–56 [0] pores associated with CA1, CA2 with 36–82 [0 or 1], CA3 with 47–84 [17–19] and CA4 with 41–95 [50] pores. Other dorsal pores of perhaps 2 types: (i) pores, each about 5 µm wide, appearing as a round clear spot; and (ii) a very small pore, also appearing as a minute clear spot about 2 µm wide; these two pore types frequent and forming part of polygonal pattern. Anal plates elongate, together narrowly quadrate, with anterior margin generally shorter than posterior margin; each plate with 3 minute setae near posterior apex plus 1 longer apical seta, and with 1–3 small pores medially; posterior third often with corrugations; length of plates 281–294 [306] µm, combined width 195–207 [220] µm. Anogenital fold with 3 minute setae at each corner of anterior margin; each lateral margin with 1 seta anteriorly and another posteriorly.

Margin. Margin with shallow corrugations, each with shallow to quite long fine radial lines or ridges, with 3–5 corrugations between 2 marginal setae. Marginal setae broadly fan-shaped, almost round to wider than long; width of each fan about 33–50 [30–50] µm, length 28–33 [33–38] µm; with about 140–166 [146] setae anteriorly on head between anterior stigmatic clefts, each side with 61–79 [63–72] between stigmatic clefts and 136–115 [116–144] on abdomen. Stigmatic clefts quite deep, each with a narrow entrance, a sclerotised inner margin and 3 (rarely 4) [3] elongate, blunt stigmatic spines, often subequal in length; length of median stigmatic spines 45–60 [50–60] µm, laterals each 33–40 [45–53] µm long. Eyespots each in a socket 100–125 µm wide, diameter of lens about 25 µm.

Venter. Derm membranous, without a submarginal band. Multilocular disc-pores frequent on either side of genital opening and on preceding two segments only, each side with 27–38 [26–38] on abdominal segment VII, 37–43 [51–61] on segment VI and 32–47 [40–45] on segment V. Spiracular disc-pores present in a narrow band, mostly 1 pore wide, between margin and each spiracle, with 45-50 [51–53] pores in each anterior band and 22–25 [27] in each posterior band, but the latter without pores in middle part of band. Ventral microducts minute, present in a group just posterior to and on either side of labium; probably present elsewhere but very sparse. Ventral setae: with 2 pairs of setae between antennae; pairs of long pregenital setae on segments VII–V (that on VII 105–135 µm long); small setae absent medially from just anterior to vulva in abdominal segment VII and very sparse elsewhere; and with a group of 4–8 slightly longer setae, each about 15–25 µm long, on either side of anal cleft near anal plates. Antennae reduced, each with 3 or 4 segments, segmental divisions between segments IV–VI indistinct or absent but usually with a pseudo-articulation in segment III; total length 195–230 [220] µm; hair-like setae present or absent associated with fleshy setae in “segments IV and V”. Clypeolabral shield 120–128 µm long. Spiracles: width of each peritreme 60–66 [61–64] µm. Legs present but very small and reduced, with a coxa, short trochanter and remaining segments fused [slightly less reduced, many 4 or 5 segmented]; without claws and digitules [some with claws and claw digitules, each digitule rather parallel-sided]; total length of prothoracic legs 6 0–83 [90–100] µm, meso- and metathoracic legs shorter, each perhaps 58–75 [90] µm;

Comments. Adult females of D. paucipedis spec. n. are very similar to those of D. expansum but differ as follows (character-states for D. expansum in brackets): (i) legs developed sufficiently to have a coxa and trochanter plus other segments fused (reduced to single-segmented leg stubs); (ii) spiracles significantly larger, each 60–66 µm wide (only 40–48 µm wide), and (iii) with many more preopercular pores, particularly associated with the more anterior clear areas (less so on specimens from Ponnuthu; absent on D. expansum )). It is just possible that these specimens represent an extreme variation of D. expansum , but the enlarged legs are considered sufficient to separate them at present.

The specimen from Ponnuthu had significantly better developed legs than those of the type series and also had no preopercular pores associated with CA1 but, as all other characters were very similar, it is here considered to be conspecific with the type series.

In showing some segmentation in the legs, adult females of D. paucipedis also resemble those of D. crenulatum but the latter species has much broader spiracular disc-pore bands, each 3 or more pores wide (only 1– 2 pores wide in D. paucipedis ), and preopercular pores are only associated with CA1 (at least associated with CA3 and CA4 on D. paucipedis ).

Host-plant. Calophyllum sp. ( Clusiaceae ).

Name derivation. The specific name paucipedis refers to the small legs, pauci- from paucus, Latin for small or little, and - pedis, Latin, masculine, for foot, and is a noun in apposition.

Figures

FIGURE 19. Discochiton paucipedis Hodgson, spec. n., adult female. Where A = leg structure of specimens from type series, Puri, Orissa, India, and B = leg structure of specimen from Ponnuthu, South India.