Zorion minutum (Fabricius)

Schnitzler, Franz-Rudolf & Wang, Qiao, 2005, Revision of Zorion Pascoe (Coleoptera: Cerambycidae), an endemic genus of New Zealand, Zootaxa 1066, pp. 1-42 : 31-33

Zorion minutum (Fabricius)

(Figs. 20, 24)

Callidium minutum Fabricius, 1775: 192 . – Fabricius, 1781: 241, 1787: 155, 1792: 332; Olivier, 1795: 57.

Clytus minutus Fabricius, 1801: 346 . – Dumont d’Urville, 1832: 592; Dieffenbach, 1843 (1974 reprint): 279.

Obrium fabricianum Westwood, 1845: 28 . – White, 1846: 20, 1855: 240; Hutton, 1873: 164; as replacement of the name Obrium minutum .

Zorion minutum Bates, 1874: 22 . – Bates, 1875: 319; Broun, 1880: 584, 1909: 147; Hutton, 1898: 158, 1904: 193; Aurivillius, 1912: 156; Tillyard, 1926: 231, 237; Hudson, 1934: 114; Dumbleton, 1957: 614; Blair, 1937: 265; Milligan, 1975: 1636; Taylor, 1957: 10; Manson, 1960: 27; Duffy, 1963: 126; Kuschel, 1990: 35, 67; Emberson, 1998: 46; Scott & Emberson, 1999: 17, 59, 80.

Diagnosis

Zorion minutum maybe distinguished from other Zorion species by the combination of an overall reddish brown body colour with yellowish white spots and the femora without a distinct dark ring as in Fig. 3 , which distinguishes it from Z. angustifasciatum . The glossy body surface distinguishes Z. minutum from Z. opacum , which has a dull body surface.

Redescription

Body length: Male 4.84–5.30 mm, female 3.48–6.36 mm.

Colour: Body red­brown throughout, with one or two yellowish white spots on each elytron, not surrounded by dark area (Fig. 20). Inner elytral spot larger than outer one and 1.4–1.9 wider than long, transversely located, not touching elytral suture, central axis through spot at right angle in relation to suture; distance between inner spot and suture 3–4

distance between outer spot and margin; distance between central axis of spot and elytral shoulder 0.4 elytral length. Central and frontoclypeal suture of head and tip of mandibles black. Scape red­brown with darker apex; pedicel dark brown; antennal segments 3–11 whitish at base but gradually becoming dark brown towards apex. Pro­ and mesocoxal cavity bounded by dark edge; trochanter dark brown; coxa red­brown; base of femur whitish without dark ring at beginning of clubbed, red­brown femur as in Fig. 3 ; tibia and tarsi reddish­brown throughout. Abdominal segments reddish­brown like remainder.

Structure: Body surface glabrous, glossy. Apex of elytra rounded. Females with a row of hairs on epipleural fold not reaching beyond anterior edge of spots; males without such hairs.

Ovipositor and spermatheca: Ratio of dorsal to ventral baculi being 1:1.3. Spermatheca sclerotised, more so at apex, strongly curved, bean shaped, wider at base and gradually tapering towards apex, no sclerotised structure within. Spermathecal gland arising at around 0.33 of spermatheca length from base.

Var ia t io n: Spots on elytral disc may be golden yellow, spots may form a fascia whose axis is at a forward angle in relation to suture or may be partially surrounded by darker area; tibia may be red­brown in middle and dark brown at base and apex.

Biology

Females were collected between 16 Oct. and 20 Dec., and males between 16 Oct. and 25 Jan. Adult hosts include Rubus flowers.

Distribution

North Island in Hawkes Bay and along east coast in the Gisborne region ( Fig. 24 ).

Comments

The holotype is badly damaged; the colour is clearly visible but the specimen is covered in dust. The right elytron is damaged, the wings are separated from the body and the abdomen is missing. Segments 4–11 of left antennae are missing, and the hind legs and body are attached to the pin by glue. The species name fabricianum was given by Westwood (1845) as a replacement name for minutus Fabricius , which he regarded as a name preoccupied by O. minutum . It is not known however, what this O. minutum is (S. Shute, BMNH, pers. comm.).

Material examined

Holotype: Ψ Callidium minutum, Joseph Banks , ( BMNH).

Other material examined: 11 Ψ, 2 ɗ. GB: Anaura Bay (2 Ψ 1 ɗ NZAC); Waikohu Valley (1 Ψ NZAC x17 256 957); Esk Valley (1 ɗ F. R. Schnitzler coll.). HB: Napier (1 Ψ BMNH); New Zealand: (1 Ψ BMNH 26579); (1 Ψ BMNH 1905 313 Sharp coll.). Unknown localities: (1 Ψ BMNH); (4 Ψ NZAC).

Figures

FIGURE 24. Known distribution of: Z. angustifasciatum; Z. batesi; Z. dugdalei; Z. kaikouraiensis; Z. minutum; Z. nonmaculatum; Z. taranakiensis; Z. opacum. The Z. batesi record on Kermadec Island is not shown here. (Map with permission from Ian Henderson, Massey University).

FIGURES 1 – 3. Ventral view of hind femora representing features of: 1, dark coloured femur; 2, light coloured femur with dark ring; 3, light coloured femur without ring.