Stictococcus subterreus Williams, Matile-Ferrero & Miller

Williams, Douglas J., Matile-Ferrero, Danièle & Miller, Douglass R., 2010, A study of some species of the genus Stictococcus Cockerell (Hemiptera: Sternorrhyncha: Coccoidea: Stictococcidae), and a discussion on Stictococcus vayssierei Richard, a species injurious to cassava in Equatorial Africa with a description of a new species from Nigeria, Zootaxa 2527, pp. 1-27 : 20-22

Stictococcus subterreus Williams, Matile-Ferrero & Miller sp. n.

( Fig. 9 )

Description. Body of adult female on microscope slide, broadly oval to almost rotund, 1.70–3.90 mm long, 1.35–3.30 mm wide, membranous at first then becoming sclerotized at maturity. Antennae 180–200 μm long, gently tapering, 6-segmented. Legs well developed, hind trochanter + femur 170-190 μm long, hind tibia + tarsus 160–180 μm long. Ratio of lengths of hind tibia + tarsus to trochanter + femur about 0.94. Ratio of lengths of hind tibia to tarsus 0.78–1.00. Claw curved, stout at base, tapering abruptly to tip, about 35 μm long, with one slender clubbed digitule longer than claw and one widely expanded digitule. Tarsal digitules knobbed, long and slender; distal inner digitule of each tarsus widely expanded distally, about as long as claw. Labium about 150 μm long, 2-segmented, shorter than clypeolasbral shield; a sclerotized ridge-like structure present on each side of basal segment, apparently joining labium to clypeolabral shield. Spiracles large and heavily sclerotized, each with sclerotized oval opening containing numerous minute papilla-like structures. Vulva wide and slit-like, at least 250 μm wide; lateral walls of oviduct with a series of minute pores. Anus situated near mid-dorsum, with a sclerotized anterior and posterior plate; anterior plate bean-shaped bearing 4 slender anterior flagellate setae and 6-8 slender posterior setae; posterior plate larger, almost quadrate, with 6 setae situated near posterior margin. A pair of long slender plates situated laterally, all 4 plates surrounded by a heavily-sclerotized oval rim, prolonged slightly posteriorly, each 230–240 μm long, 195-220 μm wide. A pair of sclerotized apodemes present, opening to derm immediately posterior to rim. Eyes present, heavily sclerotized, protruding, each measuring 30 μm at longest axis.

Dorsal surface of body with a series of long serrated or barbed setae, each 90–135 μm long, and almost pointed distally, longest setae usually situated at posterior end of body. A submarginal row of shorter setae, mostly about 35 μm long, also present, each either slender and expanding only slightly at apex, or wider and expanding widely to denticulate apex. A submarginal row of setae present, these represented singly on each segment. Each seta barbed, ranging in shape from slender and expanding slightly at apex, each about 70 μm long, to shorter and stouter setae, each about 55 μm long and widely expanding to denticulate apex. Some slender barbed setae, each about 35 μm long, present medially around anus and on head. Other setae present, short, usually curved and pointed, each about 20 μm long, fairly numerous, evenly distributed but absent from intersegmental areas. Pores present, diverse in shape, abundant. A series of circular depressions, each with peripheral quinquelocular pores about 7.5 μm in diameter, present around submargins of body and submedially on abdomen; a row also present medially next to anus. Bilocular pores, each 10.0–12.5 μm long and 7.5 μm wide, sometimes replaced by trilocular pores, present in a marginal zone. Similar smaller pores, each about 8.75 μm long or in diameter, and others about 6.25 μm long, associated with small circular pores, each about 6.25 μm in diameter with pointed peg-like centre, often mixed and distributed in whorls or in circles over body surface. Quinquelocular pores, similar in shape to those in circular depressions but smaller, each about 5 μm in diameter, present in a more or less single to double row from apex of abdomen to near base of abdominal segment VII. A series of small reticulated areas present singly on intersegmental lines submarginally.

Ventral surface of body with a marginal series of stout setae, sometimes each seta bluntly pointed, 45–50 μm long, sometimes thicker and bluntly pointed, each 35–45 μm long, or thick and expanding to a flat denticulate or lobulate apex with 2–4 lobules. Some specimens with a mixture of all 3 major types of marginal setae present. Ventral setae mostly short and stout, each almost narrowly conical and bluntly pointed, 20–25 μm long, distributed across segments; conspicuous rows present anterior and posterior to vulva; row immediately anterior to vulva also accompanied by long, thick flagellate setae, each about 65 μm long. Other long flagellate setae present submedially on thorax and between antennae; a few short flagellate setae also present medially on thorax next to short thick setae. Tubular ducts present, each about 15 μm long and very slender, fairly evenly distributed over surface. Quinquelocular pores, each about 5 μm in diameter, present in a marginal series, continuous from a compact group immediately posterior to vulva to apex of abdomen, then in more or less single rows extending medially between segments; rows on thorax extending to spiracular openings and all rows connected submarginally except on prothorax and head where each row connects near anterior spiracle to join marginal row near eye. Each marginal row of quinquelocular pores extending from between prothorax and mesothorax, mesothorax and metathorax, metathorax and abdominal segment I, and between each of abdominal segments I–IV and at apex of abdomen, each indicated by a small crescentic sclerotized plate. Sometimes a few quinquelocular pores present in these rows extending onto dorsal surface. Bilocular pores, occasionally trilocular, present around body margin slightly medial to marginal quinquelocular pores, each with thick rim 7.5 μm long.

Material examined. Holotype adult female, Left label, attended by Anoplolepis tenella . Right label, Nigeria, Bakoko Village, 13 km N of Calabar, on cassava, Colocasia sp. [ Araceae ] and Xanthosoma sp. [ Araceae ], 9.ix.1978, J.C. Reid ( BMNH). Paratypes, Nigeria, same data as holotype, 5 adult females on 3 slides ( BMNH); same data 1 adult female ( USNM); same data but 10.viii.1979, 2 adult females ( BMNH); Cross River State, Ikot Oken,, 13 km N of Calabar, base of cassava [ Manihot esculenta ], 1.xii.1981, J.C. Rerd, 8 adult females, 2 second-instar female nymphs, 2 first-instar female nymphs on 6 slides ( BMNH), 3 adult females ( MNHN), 1 adult female ( USNM); same data but 1.xii.1981, on subterranean parts of cassava, 2 adult females ( BMNH); same data but 6.vii.1981, 5 adult females ( BMNH); Ominame, 13 km N. of Calabar, on Costus afer (Zingiberaceae) , underground, ant attended, 1.xii.1981, J.C. Reid, 3 adult females ( BMNH).

Comments. There is some variation in the shapes of the ventral marginal setae in all the material examined, but this new species differs from other species in having slender and tapering marginal ventral setae. All specimens lack the long marginal flagellate setae, but sometimes there are a few marginal setae that are longer than the others but are quite thick.

Figures

FIGURE 9. Stictococcus subterreus Williams, Matile-Ferrero & Miller sp. n., adult female.