In total 27 Insect pest species on Chrysanthemum were found in 2010 at Tay Tuu, Tu Liem, Hanci three species appeared with high frequency: Pleotrichophorus chrysanthemi Theobald (Aphididael Frankliniella occidentalis (pergande) (Thripldae) and army worm Spodoptera litura (F.) (Noctuidael). Season effected species composition, in spring - summer season, appeared 23 species, In summer. autumn 19 and autumn - winter 11 species respectively. The obtained. 26 species of natural enemies on Chrysanthemum belong to 6 orders of Insecta and Araneida. Two species appeared with high frequency. The lady bird beetle Menochilus sexmaculatus F (Coccinellidae) and the army worm parasitoid Microplitis prodeniae Rao et Kurian (Braconidae). The army worm S. litura, the greenish aphid P. chrysanthemi and the thrips F. occidentalis damaged both chrysanth varieties from transplanting to harvesting. The density of army worm on the yellow chrysanth variety was similar to that of the white variety, but in spring - summer season and in autumn. winter season, the density of army worm was distinctly higher than in summer - autumn season (3.9 - 4.0 individuals/m2 compared with 1.4 - 1.5 individuals/m2, respectively). For the greenish aphid, the density of it on chrysanth in spring - summer season was higher (10.5 - 13.9 Individuals/plant) than in summer. autumn season (3.1 - 4.6 Individuals/plant) and in autumn - winter season (6.2 - 9.0 Individuals/plant). On yellow chrysanth variety, the density of greenish aphid was usually lower than on wihte chrysanth variety. And the density of thrips F. occidentalis in spring - summer season was rather lower than in summer-autumn and autumn - winter season. On the yellow chrysanth variety, the density of thrips was higher than on the wihte chrysanth variety (5.6, 10.2 and 9.6 Individualslleaf/flower in each crop comparing with 2.0, 7.7 and 3.2 individualslleaf/flower, respectively).
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