Abstract: Host recognition time is one of the important parameters in optimal host acceptance models. Aimed to assess the parasitization hazard of different Spodoptera exigua instar larvae by Meteorus pulchricornis, the host recognition time for first and successive attacks were recorded under nonchoice condition, and fitted by the Cox proportional hazard model of survival analysis. In the meantime, the survivor functions of different instar larvae as affected by parasitization experience were estimated by KaplanMeier method. The Cox proportional hazard model fitting with the host recognition time for first attack showed that host L1 was not susceptible to parasitism, but L3, L4, and L5 were more prone to be attacked than L2 by 2.6-4,0fold. However, the modelfitting with the host recognition time for successive attacks did not detect significant differences among host instars. The survival curves measuring the fraction of unparasitized host larvae were compared for the first and successive attacks, which indicated that the host recognition time for the first attack of L2, L3, and L4 was much less than that for the successive attack. It was suggested that higher instar larvae were more likely to be attacked by naive parasitoids.
〖KH*3/5D〗

Key words: Solar greenhouse, Continuous cropping, Microflora, Enzyme activity, Cucumber