The effects of forest fires on three species of Stick Insects (Phasmatidae Phasmatodea) occurring in plagues in forest areas of south-eastern Australia.

By K. G. Campbell,
Forestry Commission of N.S.W.

Proceedings of the Linnean Society of New South Wales, 86(1): 112-121

(Plate iv.)

Synopsis.

Page 112

The effect on three species of phasmatids of forest fires, both “wild” or bushfires and controlled burning, practised as a sylvicultural technique in Forestry, is studied. Two field experiments using a controlled fire were carried out at Wedding Bells State Forest near Woolgoolga, N.S.W. (where C. tessulatus (Gray) is present) and at Konangaroo State Forest, near Jenolan, N.S.W. (where P. wilkinsoni Macleay and D. violescens (Leach) occur) in order to study the effect of such fires on the egg stage of these insects. The results of these were analysed and the conclusions reached as to their effects on this stage are presented.

Bushfires which occurred during 1957 in the Jenolan and Hanging Rock-Nundle State Forest areas were studied to determine their effects in the nymphal and adult stages of the stick insects and the results are discussed.

Conclusions drawn from the results of these experiments, field studies and observations made are as follows: (1) That unless a fire consumes the litter on the forest floor down to the mineral earth there will be little deleterious effect on either eggs containing developing embryos or the larvae of the Myrmecomimesis sp. wasp; (2) Fires affecting the nymphal or adult stages can operate as a destructive factor having a long-term depressant effect on phasmatid populations and can modify the forest stand to such an extent as to reduce such populations to a very low density; (3) That the effects of such fires will be dependent on a number of factors, including the intensity of the fire, the condition and type of the forest stand, and the litter on the forest floor.