Metaxina ornata, Broun, 1909

Johnson, James B., Emberson, Rowan M. & Marris, John M. W., 2008, Biology ofMetaxina ornataBroun (Coleoptera: Metaxinidae), with Notes on Associated Beetle Taxa, The Coleopterists Bulletin 62 (2), pp. 215-219 : 215-219

Metaxina ornata collection sites, habitat and associated beetle taxa

The initial discovery was made at Glentui Bush, near Oxford, New Zealand, 43 12.024S, 172 15.043E, at about 450 m, in a dense stand of black beech, Nothofagus solandri solandri (Hook. f.) Oerst., with abundant margarodid scales, Ultracoelostoma assimile (Maskell) , and sooty mold, probably a mixture of species as reported by Hughes (1966), on the tree trunks. Most large branches also supported scales and sooty mold on their basal sections. Smaller branches arising directly from the tree trunks were usually high in the trees and were more sparsely infested. Thus, it was fortunate to find a small, live branch (basal diameter ca. 8 cm) that originated only 2 m above the ground on a moderate sized tree (basal diameter ca. 30 cm). This branch appeared to have been damaged early in its development as it curved sharply upward and divided into three nearly vertical arms that ran sub-parallel to the trunk. This branch was densely infested with scales and sooty mold. The sooty mold abundance was sufficient to almost entirely suppress the growth of mosses and lichens that were common on other

215

216 small branches. The branch was selected on this basis as an opportunity to observe the scale insects and the associated sooty mold-inhabiting insect community.

The branch was collected on 1 October 2000. There was no external evidence of insect activity when the branch was taken. Most of the foliage was removed, with a sample retained for identification. The wood was cut into approximately 30-cm long sections and placed into two 24 X 24 X 38 cm metal rearing containers, each with a glass jar emergence trap accessible via a ventilated metal duct. On 5 October adult beetles representing several species, including M. ornata , were seen in the seen in the trap jar. A late-instar M. ornata larva [consistent with the description of Crowson (1964)] appeared on 6 October. Ultimately this heavily infested branch yielded 16 adults, seven larvae and one pupa of M. ornata . This sample also yielded six additional beetle taxa ( Table 1 ).

On 10 October 2000, six, small branches (basal diameter, 6 cm), each from a different tree near the original collection site, with the more typical sparse sooty mold, plus moss and lichen growth, were taken at Glentui. A second branch similar to the original sample could not be located. These less heavily scaleinfested branches with sparse sooty mold yielded only two adults and one larva of M. ornata , though they totalled approximately one half the branch length and mass of the original branch.

A sample of six, small (basal diameter, 6 cm) moss and sooty mold-laden branches of N. s. solandri was taken along Highway 1, 30 km north of Kaikoura on 10 October. The longitude and latitude of this site were not recorded. These samples were prepared as described above. The branches from north of Kaikoura yielded two adult M. ornata , and the other beetle taxa in Table 1 , excluding S. quisquilinus .

A sample of seven, small (basal diameter, 6 cm), sooty mold and moss covered branches from mountain beech, Nothofagus solandri cliffortioides (Hook. f.) Poole, collected at Craigieburn Picnic Area, Craigieburn Forest Park, 43 9.102S, 171 43.820E, a higher elevation site at ca 800 m above sea level, on 8 December 2000. The sample was handled similarly and yielded two, middle-instar M. ornata larvae in the trap jar of the rearing container on 14 December. Other beetle taxa present in the sample included Triphyllus hispidellus , D. punctata and Amarotypus edwardsi Bates ( Carabidae : Migadopini ).