The Influence On Food Intake Capacity And Fecundity Of Ummelita Insecticeps Under The Pesticides Action

Through a fluorescent labeling approach, this thesis focuses on a quantitative analysis of the food intake of Ummelita insecticeps (Bosenberg et Strand) which is the dominant species of spider population in paddy field and measures the influence of various factors, such as, the ratio of spiders to leafhoppers, pesticide, and so on, on the food intake of Ummelita insecticeps so as to provide accurate parameters for integrated pest management (IPM) in paddy field and the theoretical basis of protecting Ummelita insecticeps. Meanwhile, this thesis also studies and measures fecundity of Ummelita insecticeps under the circumstances of various pesticide density.1.Contents of fluorescence of the Nephotettix cincticeps adults in different growth and development stages of the late riceIn five days of each growth and development stages of the late rice (the rice seedling stage, the tilloring stage, the booting stage, the tasseling stage and the milking stage), the contents of the fluorescence absorbed by each Nephotettix cincticeps adult on average from the rice plant totally are 0.0032μg, 0.0031μg, 0.0031μg, 0.0030μg and 0.0031μg. Converted into biomass unit, each gram dry biomass of Nephotettix cincticeps contains 1.226μg,1.227μg,1.188ug,1.213μg and 1.212μg every day in different growth and development stages of the late rice.The result of analysis of variance shows that the differences between food intake of per Nephotettix cincticeps individual are inconspicuous in different growth and development stages of the late rice (P>0.005). 2. Influences of different spiders' density and leafhoppers' density on food intake of Ummelita insecticepsIn the space of 225cm~3, the more the spiders, the less the food intakeof per Ummelita insecticeps individual is (4.130 > 2.675 > 2.527). When the density of Ummelita insecticeps is one-spider groups, three-spider groups and five-spider groups respectively, the number of per Ummelita insecticeps individual's predating the Nephotettix cincticeps adults is 4.130, 2.675, and 2.527 correspondingly. The result shows that 1 I 5 is the most favorable ratio of spiders to leafhoppers for spiders' predating. The differences between the food intake of one-spider group and that of three-spider groups or five-spider group are quite conspicuous (P < 0.01). But the differences between food intake of three-spider group and five-spider group are inconspicuous (P > 0.05).When the space of 225cm3 contains 5, 7 and 9 leafhoppers respectively, the food intake of a tested spider on average in three days is 3.190, 3.059 and 3.082. The results of analysis of variance show that the differences of the food intake among three spider groups with various leafhopper densities are not distinctive (P > 0.05). Therefore, the food intake of Ummelita insecticeps, which are confined in a limited space of 225cm3, is inconspicuous influenced by the leafhoppers' density, but their own density.3. The influence on predatory function of ummelita insecticeps under the pesticides actionIn the different rice period the food intake of the spiders is that rice seedling stage are 2.4 individual, 2.7 individuals, 2.4 individuals, and 1.9 individuals;tilloring stage all are 3.0 individuals;booting stage are 3.5 individuals, 3.2 individuals, 3.0 individuals, and 3.0 individuals;tasseling stage are 3.6 individuals, 3.3 individuals, 2.9 individuals and 3.3 individuals and milking stage are 3.1 individuals, 3.0 individuals, 3.0 individuals and 3.0 individuals totally in three days after spraying the pesticide with the pesticide concentration varied from 1 .' 5000 to 2 '■ 5000 still to 3 : 5000.The result of analysis of variance on the food intake of Ummelita insecticeps after different spraying times shows the following conclusion: The food intake of the spiders sprayed different pesticide densities is quite conspicuous in the rice seedling stage. The food intake of the spiders sprayed different pesticide densities is conspicuous in the booting stage and tasseling stage, and the differences are inconspicuous in other rice periods.4. The food intake of Ummelita insecticeps in different growth and development stages and the same pesticide densityIn different rice growth and development stages, when pesticide density is 0:5000, the food intake of the spider are the most in booting and tasseling stages, and then is the milking stage, the tillonng stage, the rice seedling stage. The result shows that differences of the spiders' food intake totally are inconspicuous.When the pesticide density is 1:5000, the food intake of the spider is: the booting stage > the tasseling stage > the milking stage > the tillering stage > the rice seedling stage. And the differences of the food intake of the spider are inconspicuous.When the pesticide density is 2:5000, the food intake of the spider is: booting stage > milking stage > tasseling stage > tilloring stage > rice seedling stage. And the differences of the food intake of the spider are inconspicuous.When the pesticide density is 3:5000, the order of decreasing the food intake of the spider is the tasseling stage, the milking stage, the booting stage, the tilloring stage and the rice seedling stage. The differences between the food intake of the rice seedling stage and that of the tilloring stage, the booting stage, the tasseling stage or the milking stage are quite conspicuous, but the differences of other rice stages are inconspicuous.5. The influence on fecundity of Ummelita insecticeps under the circumstances of various pesticide densitiesWhen the pesticide densities are 0:5000, 1:5000, 2:5000 and 3:5000 respectively,the egg-sac numbers of the female spiders produced are 57^ 45 > 10 and 8, in which the invalid are 4, 3,0 and 1 correspondingly. With the increase of the pesticide densities, the total numbers of eggs laid by per female Ummelita insecticeps decrease gradually, i.e. 1620,1182, 283, and 172. The number of per egg-sac is the most (28.4) when the pesticide densities are 0:5000. And it is the least (21.5) when the pesticide densities are 3:5000;when the pesticide densities are 1:5000 and 2:5000 respectively, the numbers of per egg-sac are 26.3 and 28.3.