Critical review of the efficiency of anti-phasmatid aerial spraying during summer 1973 in the mountain ash forests of the Victorian Central Highlands.  J.A. Harris.  September 1974.  15 pp. (unpubl.)

SUMMARY

This report reviews the efficiency of the January, 1973 anti-phasmatid aerial spraying in the Central Highlands of Victoria.

The study is based on results of a survey carried out in winter 1973. Spraying operations were completed on January 17 before oviposition commenced in 1973, and were confined to Upper Yarra and Neerim South districts. For the first time since 1961 no defoliation occurred within, or adjacent to, the sprayed area in these districts. The results showed a substantial reduction in the phasmatid population density on sprayed sites, where critical populations had been detected in the 1972 survey, and the density and distribution of the population oviposited on those sites was comparable to that on unsprayed sites.

In the West Tyers area of Erica district, a critical phasmatid population was undetected in the 1972 survey and defoliation occurred. This undetected critical population was useful as an indication of what would have happened if the 1973 spraying area had not been sprayed, as defoliation did in fact occur where a critical population was not sprayed.

The distribution of potentially critical samples, containing ≥5 sound early eggs/sample (Harris and Neumann, 1972) indicated a potential for phasmatid population increase in Carters Creek locality, Neerim South district, New Turkey locality in Upper Yarra district and throughout Erica district.

Also published:

Neuman, F.G., Harris, J.A. and Wood, C.H. (1977)  The phasmatid problem in mountain ash forests of the Central Highlands of Victoria.  For. Comm. Vic., Bull. 25, 43 pp.

Harris, J.A. (1981)  The effect of the insecticide maldison on Didymuria violescens (Leach) (Phasmatodea : Phasmatidae) and on the sub-canopy insect fauna in mountain ash forests of the Central Highlands of Victoria.  M.Sc.Thesis, Univ. of Melbourne, 237 pp.