[Suppressive effect of plant secondary substances and ecological measures on Liriomyza sativae population]

A state-space population model was used to evaluate the effect of plant secondary substances and ecological measures on the population dynamics of the vegetable leafminer, Liriomyza sativae. In the vegetable field, by spraying alcohol extracts of Lantana camara (1 g.100 ml-1), or spraying the petroleum spray oil (300 x), or releasing the parasitoids, the indices of population control(IIPC) of L. sativae compared with control were 0.136, 0.222 and 0.292, respectively, but the index of population trend of vegetable leafminer in control was as high as 11.15, the population of vegetable leafminer still increased by control each one of the methods. Based on the state space analysis, the controlling effects of the alcohol extracts combining with other methods on vegetable leafminer were stimulated, which showed that the alcohol extracts from Lantana camara (1 g.100 ml-1) plus horticultural spray oils(300 x) used once at the period of adult summit, and the parasitoids released 1000 to 2000 per 100 m2 gave the index of population of vegetable leafminer below 1, means that vegetable leafminer would be controlled sustainably.