Fistulococcus pokfulamensis Hodgson & Martin

Fistulococcus pokfulamensis Hodgson & Martin 2005: 7 .

Material examined: INDIA, Karnataka: Kodathi, Seri-biotech Research Laboratories, N 12.8882°, E 77.716 0 °, on Heptapleurum actinophyllum (Endl.) Lowry & G.M. Plunkett (Araliaceae), 17.ii.2021, Sunil Joshi coll., 12 ♀♀; on Syzygium cumini (L.) ( Moraceae), 8 ♀♀; Bengaluru, HBR Layout, N 13.0353°, E 77.6285°, on Mangifera indica L. ( Anacardiaceae), 28.viii.2021, V. Maroli coll., 7 ♀♀; on Vaccinium corymbosum L. ( Ericaceae), 5 ♀♀.

Appearance in life (Fig. 1d): Body of adult female usually broadly oval but occasionally asymmetric, quite flat but with a slight longitudinal ridge anterior to anal plates. Dorsum covered in a dusting of white wax, with white wax threads or filaments appearing to arise from near margin; after removal of wax (Fig. 1d), dorsum transparent yellow with brownish alimentary canal clearly visible through dorsal cuticle.

Diagnosis of slide-mounted adult female (n=32): Body membranous, narrow at anterior and broadest at abdomen (Fig. 5q), usually broadly oval but occasionally asymmetric; anal cleft about 1/10 th of total body length. Marginal setae each with a blunt apex (Fig. 5a) and highly sclerotized basal socket. Stigmatic clefts each highly sclerotized with constriction at body edge, without any stigmatic setae (Fig. 5b).

Dorsum: Dermal areolations restricted to margin and submarginal areas (Fig. 5c). Setae (Fig. 5d) abundant in groups of 3–6 (occasionally groups of 2 or 3) between submarginal chambered ducts, usually arranged in a crescent. Pores of 3 types: small pores associated with microducts, frequent on submarginal areas (Fig. 5e); concave pores larger than pores associated with dorsal microduct (Fig. 5f), present submedially and submarginally; and preopercular pores (Fig. 5g), abundant in 2 bands arising from anal plates and extending to head. Submarginal chambered ducts (Fig. 5h), each consisting of one large tubular duct with about 8–12 satellites (funnel-shaped pores forming a Ushaped area of sclerotization by opening of main duct) plus 3–9 setae, restricted to submargin. Anal plates (Fig. 5i) with 4 strong setae (Fig. 5j); both anterior and posterior inner margin setae, apical setae and outer margin setae.

Venter: Anogenital fold with 2 setae, situated at each corner on anterior margin (Fig. 5k) and 4 setae, on lateral margin (Fig. 5l). Multilocular pores very few (Fig. 5m). Antennae each 6 segmented (Fig. 5n), segmentation obscure. Spiracle (Fig. 5o) normal, without sclerotic plate. Legs much reduced, segmentation between tibia and tarsus unclear (Fig. 5p); setal distribution: coxa 3; trochanter 2; femur 1; tibia 2; tarsus 4.

Comparison: Only two differences between the specimens described by Hodgson and Martin (2005) and specimens examined in this study were noted. Our specimens are much larger (length 3.6–4.8 mm, width 1.8–2.6 mm) compared to their measurements (length 2.2–3.5 mm, width 1.0–2.0 mm). While they recorded setae on the anogenital fold, Hodgson and Martin (2005) did not comment on lateral margin setae but illustrated a single seta on the lateral margin of the anogenital fold. In contrast, the specimens examined in this study possessed four lateral margin setae on the anogenital fold. We regard the morphological differences between the Indian specimens examined and those described by Hodgson and Martin (2005) as simple morphological variations within the species.

Ecological notes: This is the first report of the genus Fistulococcus from India, and is very interesting as the species was known previously only from Hong Kong, infesting a gymnosperm, Gnetum luofuense (family Gnetaceae) (Hodgson & Martin 2005). However, in India it was recorded on four different, economically important flowering plants: Heptapleurum actinophyllum (Araliaceae) (Fig. 6a), Syzigium cumini (Moraceae) (Fig. 6b), Mangifera indica (Anacardiaceae) (Fig. 6c) and Vaccinium corymbosum (Ericaceae) (Fig. 6d). The record of its infestation on M. indica deserves special attention as mango is grown extensively in India and has a high economic value. The scale insect was found to be attended by the ant Oecophylla smaragdina (Fabricius) ( Hymenoptera: Formicidae) in large numbers (Fig. 6e).

Hodgson and Martin (2005) provided a taxonomic account and illustration of F. pokfulamensis, and remarked that it would be interesting to know if the species is restricted to gymnosperms. Our study clearly indicates that it also infests angiosperm species that have very pronounced leaf veins.

Four species of predators were recorded attacking F. pokfulamensis in the field: Chilocorus nigrita (Fabricius) (Fig. 6f), Cryptolaemus montrouzieri Mulsant ( Coleoptera: Coccinellidae) (Figs 6g & h), Spalgis epius (Westwood) ( Lepidoptera: Lycaenidae) (Fig. 6i), and Dipha aphidivora Meyrick ( Lepidoptera: Pyralidae) (Figs 6j–m), all feeding on nymphs and adult scales. This prey record for D. aphidivora is noteworthy, as it had previously been recorded only feeding on aphids belonging to the tribe Cerataphidini: Ceratovacuna lanigera Zehntner, Pseudoregma alexanderi (Takahashi) and P. bambucicola (Takahashi) (Arakaki & Yoshiyasu 1988); this is the first time that D. aphidivora has been recorded attacking a scale insect belonging to the family Coccidae .