| Icerya aegyptiaca (Douglas) has become one of the most important pests on ornamental plants in Guangzhou area in recent years. As a polyphagous insect pest Icerya aegyptiaca feeds on several hundreds of host plants, including many ornamental plants and a few fruit trees, such as citrus, jackfruit, sweetsop and guava etc.Host plants are injured directly by female adults and nymph of the pest which gathering on the undersides of leaves, young shoots and branches, and indirectly by sooty mould led by the honeydrew of the insect pest.Biological, ecological characteristics of Icerya aegyptiaca and its control measures were carried out from 2003 to 2005 in Guangzhou area. The main results are as following.1) Five or six severe overlapped generations of Icerya aegyptiaca took place in Guangzhou area. Activities of feeding, development and reproduction of the pest go on in winter, with every state being visible. As the male adults were very rare, the pest reproduces by parthenogenesis, with average fecundity as 163.5 young nymph per female, up to 300 young nymph per female at most.2) It has been found that more than thirty-five ornamental plants were attacked by Icerya aegyptiaca in Guangzhou, majority of them belonging to Magnoliaceae, such as Michelia alba, Acronychia pedunculata, Psidium guajava, Magnolia grandiflora, Manglietia megaphylla etc.3) The spatial distribution of Icerya aegyptiaca belonged to aggregation pattern by means of the law of Taylor power, indices of m and m/m of Lloyd and m-m of Iwao.4) Population dynamics of both Icerya aegyptiaca and its main natural enemies, namely, Rodolia pumila Weise and Anisochrysa sp., showed two peaks each year in Guangzhou area, appearing during the periods of late spring to early summer and late fall to early winter, respectively. The population densities of pest were as 32.3 and 20.9 individuals per leaf, respectively.5) The predation effects of the main natural enemies, i.e. the ladybird beetle, R.pumila, and the green lacewings, Anisochrysa sp., on Icerya aegyptiaca were studied in laboratory in the light of the functional response. Both predators prefer to feed on the first instar nymph of the prey. Results of all experiments displayed that functional response belonged to Holling-Typeâ…¡. It was also found that temperature could change the parameters of the equations, but could not change the response type. The searching efficiency of the ladybird beetle increased with temperature changed from 17C to 32C, but dramatically decreased at 35C.6) The results of field trials of chemical control revealed that ideal control effects were got from the treatments of phoxim plus admire, special and horticultural mineral oil, as more as 95.6, 95.3 and 94.8%, respectively, followed by the treatments of Rongjie, mineral oil plus Springtac, D-Ctron and mineral oil, as 84.2, 84.1, 78.8 and 69.9%, respectively. The test was suggested that the mineral oil could be considered as the first choice in practice of controlling Icerya aegyptiaca since it is cheaper, friendly to environment and safely to natural enemies.
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