Prior to the 1960’s, research in the field of forest entomology was generally in response to specific issues arising in either native forests or exotic softwood plantations predominantly composed of Pinus radiata D.Don (Radiata pine). Such responses usually involved a specific pest issue requiring a localised evaluation and response.

In the 1960’s however, a number of insect pest issues arose in Victoria, most notably, the detection of Sirex noctilio (Fabricius) (Sirex wood wasp) in Victoria’s Radiata pine plantations and, outbreaks of the native insect Didymuria violescens in Eucalyptus delegatensis RT Baker (Alpine ash) and E. regnans F Muell (Mountain ash) forests of Victoria. While these outbreaks represent only part of the broader pest issues encountered, both these insects and their economic and aesthetic impacts over a wide area of the forests of Victoria required the development of a more coordinated approach to forest entomology and a specific focus on further research to understand the dynamics of both insect and related arthropods in Victoria’s forest estate.

Subsequent research efforts focused on, but were not necessarily confined to, five broad themes of research including:

• Conservation entomology
• Insect pests of exotic tree species
• Insect pests of native forests
• Insect pests of hardwood plantations
• Control options including quarantine and Forest Health Surveillance (FHS)

Examples of the work conducted in these themes cover within conservation entomology, the extensive research undertaken on the natural and artificial ecological disturbances on litter arthropods in E. regnans forests, and the effects of fuel reduction burning and fire-retardant application on arthropods and earthworms in the dry sclerophyll forests and Central Victoria. With reference to exotic tree species, in addition to groundbreaking research on the causes of Sirex outbreaks and associated control options, extensive research was also undertaken on the management of Ips grandicollis (Eichhoff), an introduced pine bark beetle which caused extensive mortality in young radiata pine plantations. Outbreaks of D. violescens in native eucalypt forests prompted extensive research into its autecology resulting in adopted management practices to monitor and where required treat such outbreaks. In addition, as the area under eucalypt hardwood plantations expanded during the 1990’s, so did research into the ecology and control of insect pests within the plantation estate, covering studies into inter and intra-provenance variation within eucalypt species thus enabling more informed management practices being implemented as to species selection for plantation establishment across the state. Increased trade also necessitated research studies being initiated into cost-effective and accurate forest monitoring programs to allow for the early detection and control of introduced exotic insect pest species posing both a threat to native flora and fauna, as well as associated economic impacts surrounding the ability to import and export goods from Victorian ports.

In terms of FHS, with international trade increasing, so does the risk of exotic pest incursions, requiring increased surveillance programs to monitor and where possible, eliminate exotic pests before they pose a risk to Victoria’s forest and plantation estate. Climate change is also considered likely to exacerbate the damage caused by existing and introduced insect pests, as shown by the potential for Sirex attack in drought-stressed softwood plantations. FHS is therefore a key requirement not only in the protection of Victoria’s softwood plantations, but also for certification allowing for the marketing and export of timber products.

The above research work represents but a small portion of the research work conducted over the past six decades by dedicated forest health scientists, technicians and field staff working across a wide range of government departments, in collaboration with industry partners and educational research institutions in Victoria and interstate. The work has not only been done as stand-alone entomological research, but also formed part of multidisciplinary studies to assist in developing our overall understanding of forest ecosystems and how the various components such as forest entomology, pathology, genetics, growth and yield research, soils, hydrology, fire regimes, nutrition, climate, land use to name a few all interact to further our understanding of the dynamics of forest ecosystems and the part insects play in such systems.

Underpinning such studies, is the importance of also ensuring research is supported by scientifically proven methodologies to ensure findings are robust and can be fully and confidently implemented in any subsequent management recommendations made. The methodologies used in entomological research are quite varied in approach and depend on a variety of factors including but not confined to for example, the terrain and vegetation type (i.e. plantations vs native forests) and the insect cohort to be assessed (i.e. litter invertebrates vs flighted insects).

An example of such a research methodology is pitfall trapping used to sample litter invertebrates in the Wombat State Forest as part of the multidisciplinary study examining the seasonal and temporal effects of fuel reduction burning in Victorian dry sclerophyll eucalypt forests. Multiple study sites representing various fire management regimens including untreated sites were established, using pitfall traps consisting of test tubes filled with preservative fluid to sample litter invertebrates at each site. The pitfall traps were established along a 100 metre transect at five metre intervals to ensure representative coverage of each site, with exposure times of one week per month over several years to ensure samples obtained were representative over a prolonged timeframe to allow for any observed variations within invertebrate populations.

The processing of tens of thousands of collected specimens to ordinal, family and species level required specialised taxonomic ability, coupled with a patient approach in handling sometimes delicate material. The findings of this study allowed more precise management recommendations to be made as to the impacts of burning on litter invertebrates and the best time as to schedule fuel reduction burns. These findings assisted in not only developing plans that protected rural communities, but also minimised the short and longer-term impacts on litter invertebrates, a crucial component of forest ecosystems.

The bibliography provided below lists published works covering forest entomological research conducted over many years. While such a bibliography aims to be as comprehensive as possible, it will for now and into the foreseeable future, remain a work in progress, with more references being added as materials become available. Any corrections and/or amendments to the bibliography, including the contribution of yet to be listed materials are welcome.

Bibliography