Research Branch Report No. 139

Beetle populations in eucalypt and pine forests in North-eastern Victoria.  F. G. Neumann.  July 1979.  27 pp. (unpubl.)

SUMMARY

Diurnal airborne populations of Coleoptera (beetles) were studied below canopy level in plantations of introduced radiata pine and mature peppermint-type eucalypt forest near Myrtleford in north-eastern Victoria. Beetle proportions in seasonal samples of the insect fauna varied between 2.2 per cent in winter and 20.8 per cent in spring. Within pine, beetle flight activity levels were higher in spring and autumn than in summer and winter, whereas in eucalypt, flight activity was higher in spring than during any other season. Intraseasonal activity varied little between study areas except during summer, when significantly more beetles were trapped in mature pine and the eucalypt compared to intermediate-age pine.

Sixty-four families were recovered, 47 from eucalypt and 31, 37 and 46 from pine of intermediate, young and mature page respectively. Most abundant in pine and eucalypt were the Chyrsomelidae, Staphylinidae, Alleculidae, Coccinelliddae, Scarabaeidae, Mordellidae, Curculionidae, Melyridae and Anisotomidae. Many Histeridae, Colydiidae and introduced Scolytidae also occurred, but were restricted to other to the older stands of pine. Scydmaenidae, Helodidae, Silvanidae, Mycteridae, Meloidea and Attelabidae, all being rare, were intercepted exclusively in eucalypt, and 17 minor families only in pine. New records for Australian pine plantations are the families: Hydraenidae, Hydrophilidae, Ptiliidae, Scydmaenidae, Silphidae, Helodidae, Rhipiceridae, Cantharidae, Lycidae, Ptinidae, Sphindidae, Silvanidae, Corylophidae, Lathridiidae, Mycetophagidae, Lagriidae, Mycteridae, Meloidae and Attelabidae.

A total of 370 species were trapped, 101 in intermediate-age pine, 126 and 129 respectively in mature and young pine, 241 collectively in pine, and 199 in eucalypt. The anobiid Ernobius mollis and the scolytids Hylastes ater and Hylurgus ligniperda, all of Northern Hemisphere origin, where the only introduced species found established exclusively on pine. In all study areas, there was greater species range during spring and summer then during autumn and winter. Beetle diversity (a function of both species composition and relative abundance) was significantly higher in mature eucalypt than in the older stands of pine, because of more even distribution of individuals among species, and greater species richness in the eucalypt. The ecology of most of the species found in the study areas requires clarification.

Also published:

Neumann, F.G. (1979)  Beetle communities in eucalypt and pine forests in North-eastern Victoria.  Aust. For. Res. 9: 227-93.