Umbonichiton Henderson & Hodgson, Hodgson & Henderson 2000
Creators: name: Henderson, Rosa C.
name: Hodgson, Chris J.
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Coccidae
Umbonichiton

description: 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).
description: Published as part of Henderson, Rosa C. & Hodgson, Chris J., 2005, Two new species of Umbonichiton (Hemiptera: Sternorrhyncha: Cocccoidea: Coccidae) from New Zealand, pp. 1-11 in Zootaxa 854 (1) on pages 2-3, DOI: 10.11646/zootaxa.854.1.1, http://zenodo.org/record/5044290