Insect pests and diseases in native forests, pine plantations and forest nurseries: A discussion paper on their importance and management in Victoria.  F. G. Neumann and G. C. Marks.  October 1989.  64pp. (unpubl.)

SUMMARY

The status in Victoria of insect pests and diseases affecting native forests, softwood plantations and forest nurseries is reviewed, as are the administrative arrangements and control measures that have been adopted to minimize dieback, tree mortality, wood degrade and decay. In native forests, important destructive agents have included: (1) the defoliators Didymuria violescens (Spurlegged Phasmatid), Cardiaspina spp. (psyllids), Uraba lugens (Gum Leaf Skeletonizer), Doratifera vulnerans (Cup Moth) and Aulographina eucalypti (a leaf blight), (2) the root rot fungi Phytophthora cinnamomi (Cinnamon Fungus) and Armillaria luteobubalina, (3) the wood degrading ambrosia beetle Austroplatypus incompertus, (4) the wood destroying termites Porotermes adamsoni (Dampwood Termite) and Coptotermes spp., (5) a complex of wood decay fungi, (6) damping-off fungi of Pythium spp., and (7) seed harvesting ants, notably Prolasius pallidus. In radiata pine plantations, Sirex noctilio (Sirex Wasp) and Dothistroina septospora (Pine Needle Blight) have caused substantial tree mortality and defoliation respectively, and in pine nurseries P. cinnamomi and the root lesion nematode Pratylenchus penetrans have killed large numbers of seedlings. Ips grandicollis and two other species of exotic bark beetle are widely distributed in plantations, but none have so far caused economically important damage. A range of indigenous insect defoliators have adapted to pine, but any outbreaks have usually been localised and of short duration.

The use of direct controls (such as pesticide spraying or prescribed burning of litter to destroy eggs of insect pests), of biological control and of cultural and genetic techniques are discussed in the context of present and future forestry needs. The threat posed by accidentally introduced pests and diseases to exotic trees in Victoria, including 200 000 ha of commercial radiata pine plantations, is highlighted. Twelve actions are specified that need to be taken by the Australian Quarantine and Inspection Service through the Victorian Chief Quarantine Officer (Plants) of the Department of Agriculture and Rural Affairs in close collaboration with CFL, the Standing Committee on Forestry and, if necessary, the CSIRO, tertiary institutions, State museums and relevant interstate Departments, to achieve rapid identification and eradication or suppression of nationally important quarantine escapes.

A total of seven statements and 18 recommendations are made concerning: (1) CFL's forest protection policy, (2) biological control in eucalypt and pine monocultures, (3) administrative arrangements within CFL for detection, survey and control of forest pests and diseases, (4) research and development activities on these agents, (5) restrictions on the use of pesticides in forests and forest nurseries, (6) CFL's commitment to the maintenance of an effective Australia-wide quarantine service and the role of Standing Committee on Forestry in relation to contingency actions for eradication or suppression of quarantine escapes, and (7) the importance of cultural controls in pine plantation management.

The technical information contained in this report is largely based on 128 scientific papers and unpublished CFL reports. The statements and recommendations therefore have a solid scientific base.

Also published:

Neumann, F.G. and Marks, G.C. (1990)  Status and management of insect pests and diseases in Victorian softwood plantations.  Aust. For. 53: 131-144.