抄録
In this paper, the temperature relationships of the development and the mortality of eggs and larvae of the brown planthopper were studied, when their parents was conditioned with different environmental conditions such as temperature, photoperiod, crowding and quality of food plant. Rearing of the parental generation in this experiment was made under the following four conditions. Case A : the rearing temperature is 27.5℃ and long day photoperiod (16 hours in light and 8 hours in dark per day), high population density (that is 10 pairs (of adult) or 20 larvae per rearing tube), seedling of rice plant as food. Case B : temperature, photoperiod and food are the same as in the case A, low population density (that is 1 pair (of adult) or 1 larva per rearing tube). Case C : temperature, photoperiod and population density are the same as in case A, leaf sheath of rice plant given as food. Case D : 28℃ of rearing temperature, short day photoperiod (that is 8 hours in light and 16 hours in dark per day), population density and food condition are the same as in case D. The incubation periods of the eggs from the female which are deposited by the female (brachypterous) of case B, become longer than that of the eggs produced by the female (macropterous) of case A (the difference can be seen at 90% level of confidence limit). Comparing the incubation periods of the eggs which are deposited by the macropterous female of case A with that of the eggs which are produced by the macropterous female of case C, the incubation periods of the former are longer than that of the latter (the difference can be seen at 80% level of confidence Iimit). There is no clear difference among all cases in the relation between temperature and developmental periods of the larvae produced by the females which were reared under the different conditions mentioned above. The developmental zeros and the total effective temperatures in the egg and each larval stage of progeny are different, when their parent was reared under the different conditions. The mortality during the larval stage is highest when the larvae were reared at 30℃ and lowest at 22.5℃. The mortality of the larvae produced from the parents reared with the rearing condition of case A or B was higher than that of the parents reared with rearing condition of case C or D.
