Umbonichiton, Henderson & Hodgson, 2000

Henderson, Rosa C. & Hodgson, Chris J., 2005, Two new species of Umbonichiton (Hemiptera: Sternorrhyncha: Cocccoidea: Coccidae) from New Zealand, Zootaxa 854 (1), pp. 1-11 : 2-3

UMBONICHITON Henderson & Hodgson

Umbonichiton Henderson & Hodgson, Hodgson & Henderson, 2000: 171 .

Type species: Ctenochiton hymenantherae Maskell, 1885: 25 .

Generic redescription: adult female. Test: glassy wax (except U. pellaspis where test is of leathery wax with fibrous strands), convex, with 7 longitudinal rows of plates, median row with six plates, each plate convex knob­like; insect beneath often bi­coloured through test. Shape: elongate oval with rounded ends. Small, length <3.5 mm; width <2.1 mm. Dorsum: derm membranous. Dorsal setae absent. Dorsal pores distributed in a reticulate pattern, delineating reticulation areas in 7 longitudinal rows across abdomen, with 9 areas between anal plates and anterior margin and 29 areas around margin; dorsal pores of 3 or 4 types, all with: (i) a small, dark microductule, inner ductule sometimes not discernible; (ii) a small simple pore, about same size as microductule pore; both pore types most frequent in reticulation lines, occasionally with 1 or 2 between reticulation junctions on margin and along margins of anal cleft; (iii) a large, heavily sclerotised macropore, shape often diagnostic of species, either cone­shaped, bollard­like, or mushroom­shaped and apparently extending above dorsal derm surface between wax plates of test, each with a round, heavily sclerotised, inner base; most abundant in median and submedian reticulation lines. Preopercular pores, dorsal tubercles and dorsal tubular ducts absent. Anal plates widest in anterior quarter, tapering to apex; with minute pores on upper surface of each plate; surface relatively smooth; each plate with two inner margin setae, each short, sharp, and fine, 1 apical seta, spinose or setose, and generally slightly longer than inner margin setae, and a posterior margin seta on upper anal plate surface, usually rather setose; without a sclerotised collar on dorsum just anterior to anal plates. Anogenital fold with two large sclerotised plates arising internally and extending anteriorly from anterior margin; with 2–4 pairs of setae along antero­lateral margin plus a pair posteriorly. Anal tube moderately long; anal ring with six setae. Margin: marginal setae small and finely spinose; with 3–12 setae on each side between stigmatic clefts; present in a single line around body but absent from inner margins of anal cleft; reticulation point setae sometimes differentiated; marginal setae on anal lobes not differentiated. Stigmatic clefts shallow, without a stigmatic sclerotisation, each usually with a stigmatic spine of moderate length, about 5–10x length of marginal spines (lacking in posterior clefts of U. bispinatus sp. nov.). Eyespot present (but hard to discern on most specimens). Venter: pregenital disc­pores with 3–8 (mainly 5) outer loculi, on mediolateral lobes of abdominal segments in a line from anal cleft extending towards each posterior spiracle; occasionally 1 or 2 present medially on segments V and VI on U. adelus ; a few sometimes present laterad to metacoxae. Spiracular disc­pores with mainly 5 loculi, in narrow bands 1–5 pores wide between spiracles and margin and with a few extending medially. Ventral microducts of one type, present in a submarginal band (throughout submargin on U. adelus ) and in segmental bands medially, except on posterior 1 or 2 abdominal segments (throughout on U. rimu sp. nov.). Preantennal pores: generally with 1 or 2 pairs present. Ventral tubular ducts of one type, present in a broad submarginal band and usually also medially on head, thorax and abdomen (absent medially on U. hymenantherae , and few on U. bispinatus sp. nov. and U. rimu sp. nov.). Ventral setae: with 1–4 pairs of anterior anal cleft setae; with a single pair of long pregenital setae on segment VII only; hypopygial setae absent; with (total) 4–9 (mainly 8) interantennal setae; other setae distributed as for family. Antennae 6­segmented, with 0–2 pseudosegments on segment III; setal distribution of antennae as for family, but longest seta on apical segment, 30­110 µm long. Spiracles typical of family. Legs well developed, with a separate tibia and tarsus but no articulatory sclerosis; tarsal campaniform pore absent; claws small and short, without a denticle; tarsal digitules knobbed, unequal in length and thickness; claw digitules expanded and equal, much longer than claw. Vulva present in segment VII.

Remarks. This genus now contains seven species: U. adelus Henderson & Hodgson , U. bispinatus sp. nov., U. bullatus Henderson & Hodgson , U. hymenantherae (Maskell) , U. jubatus Henderson & Hodgson , U. pellaspis Henderson & Hodgson , and U. rimu sp. nov.

Generic diagnosis: Species in the genus Umbonichiton are characterised by the following combination of characters: (i) few spinose marginal setae, but with moderately long stigmatic spines (at least in the anterior stigmatic clefts); (ii) presence of very large sclerotised dorsal macropores of either cone, bollard, or mushroom­shape; (iii) very small simple pores and apparently ductless microductules in dorsal reticulation lines; (iv) a broad submarginal band of ventral tubular ducts, and (v) pregenital disc­pores restricted to either side of the anal cleft and on the abdominal medio­lateral lobes [See Hodgson & Henderson 2000: page 24], forming a line between the anal cleft and posterior spiracles. In addition, the genus is characterised by a knobbly glassy test (except for U. pellaspis , which has a unique test made up of leathery wax with fibrous strands).