The Study On Interspecific Competition Between Tribolium Castaneum And Oryzaephilu Surinamensis

The interspecific competitive relationship between T. castaneum and O. surinamensis was studied in the paper. Studied the population change of T. castaneum and O. surinamensis under single and mixed feeding, T. castaneum and O. surinamensis spawning competition and the development of larval stage, the competition between T. castaneum and O. surinamensis in different insect state and the impact of p-Toluquinone on the larval or adult of O. surinamensis by the defensive secretions of T. castaneum separately. In order to clear the population change between the two stored grain pests and finally providing basic reference in scientifically predicting the population change of T. castaneum and O. surinamensis. Research findings:(1) All the two main stored grain pests’ populations present a parabolic trend. The population of T. castaneum increased rapidly and at the ending of the experiment had reached 449.33. While the population of O. surinamensis increased slowly and at the ending of the experiment only about 112.67~142.33. The population of T. castaneum under mixed rearing could reached as higher as 484.67. There was no significant difference of the population of T. castaneum under mixed or single feeding. The population of O. surinamensis increased a little just at the beginning of the experiment and the population of O. surinamensis reduced gradually with the population increasing of T. castaneum. At the ending of the experiment the adult of O. surinamensis only had 2.67~11.67.(2) There were 314.50~379.00 adult of T. castaneum occurred during the single feeding and the adult of O. surinamensis were 62.00~95.67. While the progeny populations of T. castaneum and O. surinamensis under mixed rearing were 468.33~542.67 and 76.00~93.00, respectively. Indicated that O. surinamensis had inhibition of eggs production of T. castaneum, but weaker than T. castaneum to O. surinamensis. After the quadratic regression analysis of the progeny populations of T. castaneum and O. surinamensis we found out that the regression equation of T. castaneum and O. surinamensis both fitted well. The regression equation coefficients of the progeny populations of T. castaneum was not less than 0.9846 and the regression equation coefficients of the progeny populations of O. surinamensis was not less than 0.9775.(3) The male and female adult of T. castaneum had influence on the eggs development to the larval, the larval development to the pupas and the pupas’ development to adult of O. surinamensis. The influence of 20 T. castaneum adults on O. surinamensis eggs, larval and pupas’ development by stronger than 10 T. castaneum adults. The developmental rate of eggs of O. surinamensis in the control group can be as high as 86.70~96.70%. The eggs developmental rate of O. surinamensis reduced to 31.70~38.40% after added in 10 adult of T. castaneum into the petri dish and the eggs developmental rate of O. surinamensis reduced to 15.00~31.70% after added in 10 adult of T. castaneum into the petri dish. While the larval of T. castaneum were not. The male and the female adult as well as the larval of O. surinamensis had no significantly influence on the eggs development to the larval, the larval development to the pupas and the pupas’ development to adult of T. castaneum with the control group, also as the population density of O. surinamensis. The addition of flour had no significantly influence on the eggs development to the larval and the pupas’ development to adult of T. castaneum or O. surinamensis, but had significantly influence on the larval development to pupa of T. castaneum.(4) The distribution of the adult of O. surinamensis on the filter paper had significant influence treated by different concentration of p-Toluquinone. The treatment group of 10 mg/ml and 1 mg/ml had stronger repellent effect than the treatment group of 0.1 mg/ml and 0.01 mg/ml. While the distribution of the adult of O. surinamensis had no significant influence on the filter paper treated by p-Toluquinone during different observation time. Though the movement of larval of O. surinamensis was not actively, the distribution of larval of O. surinamensis on the filter paper had significant influence treated by different concentration of p-Toluquinone. The distribution of larval or adult of O. surinamensis was not clear on the flour treated by different concentration of p-Toluquinone, maybe the flour odor interferenced the test result. But the flour treated by 10 mg/ml p-Toluquinone had repellent effect on larval or adult of O. surinamensis. During the experiment, there are larval of O. surinamensis deaded in the flour treated by 10 mg/ml p-Toluquinone. While the other groups treated by lower concentration of p-Toluquinone were not.