GOLDEN OAK SCALE
Asterodiaspis variolosa (Ratzeburg) -- Coccidae
[Also named Asterolecanium variolosum (Ratzeburg)]
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This pit-making scale became an important pest on exotic oak trees in New Zealand and Tasmania in the 1920's and in mainland Australia in the 1930's, but was most severe on golden oak, Quercus pedunculata Ehr. (Dahlsten & Hall 1999). Growth is retarded on severely infested trees and dieback follows, with some young trees being killed (Johnson & Lyon 1976). The parasitoid Habrolepis dalmanni (Westwood) was introduced from the eastern United States into New Zealand in the 1920's and later into Tasmania and Australia from New Zealand, followed by an introduction to Chile from the United States (Dahlsten & Hall 1999). Complete biological control resulted in New Zealand, with partial to substantial control in mainland Australia, Tasmania and Chile (Clausen 1978).
For greater details of the biological control efforts, and biologies of hsots and natural enemies, please see the following (Howard 1898, Gourlary 1935, Clark 1936, Evans 1939, Parr 1940, Russell 1941, Craighead 1950, Dowden 1950, Pritchard & Ceer 1950, Wilson 1960, Gonzalez & Rojas 1966).
REFERENCES: [Additional references may be found at: MELVYL Library ]
Clark, A. F. 1936. Biological control of forest insect pests. New Zealand J. Sci. & Tech. 18: 585-88.
Clausen, C. P. 1978 (ed.). Introduced parasites and predators of arthropod pests and weeds: A world review. USDA ARS Agriculture Handbook No. 480. 455 p.
Craighead, F. C. 1950. Insect Enemies of Eastern Forests. U. S. Dept. Agric. Misc. Publ. 657. 379 p.
Dahlsten, D. L. & R. W. Hall. 1999. Biological control of insects in outdoor urban environments In: Bellows, T. S. & T. W. Fisher (eds.), Handbook of Biological Control: Principles and Applications. Academic Press, San Diego, New York. 1046 p.
Dowden, P. B. 1950. Bees, wasps, ants and parasites. In: F. C. Craighead (ed.), Insect Enemies of Eastern Forests. U. S. Dept. Agric. Misc. Publ. 657: 591-637.
Evans, J. W. 1939. Oak Insects. Tasmanium J. Agric. 10: 199-205.
Gonzalez, R. H. & S. P. Rojas. 1966. Estudio analítico del control biológico de plagas agrícolas en Chile. Agric. Tech. 26: 133-47.
Gourlary, E. S. 1935. Parasites of the golden oak-scale. The establishment in New Zealand of Habrolepis dalmanni Westwood. New Zealand J. Sci. TEch. 16: 216-35.
Howard, L. O. 1898. Two beneficial insects introduced from Europe. U. S. Dept. Agric. Bull. 17 (n.s.): 13-16.
Johnson, W. T. & H. H. Lyon. 1976. Insects that Feed on Trees and Shrubs. Comstock Publ. Assoc., Cornell Univ. Press, Ithaca, NY. 464 p.
Parr, T. 1940. Asterolecanium variolosum Ratzeburg, a gall-forming coccid, and its effect upon the host trees. Yale Forest. School Bull. 46: 1-49.
Pritchard, A. E. & R. E. Beer. 1950. Biology and control of Asterolecanium scales on oaks in California. J. Econ. Ent. 43: 494-97.
Russell, L. M. 1941. A classification of the scale insect genus Asterolecanium. U. S. Dept. Agric. Misc. Pub. 424. 322 p.
Wilson, F. 1960. A review of the Biological Control of Insects and Weeds in Australia and Australian New Guinea. Commonwealth Inst. Biol. Control, Tech. Commun. 1. 102 p.