• The Korean Journal of Ecology
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• v.27 no.6 s.122
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• pp.369-373
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• 2004

The water strider, Gerris paludum insularis, was reared in a growth cabinet at two constant temperatures and ${\approx}20^{\circ}C$ under a 16:8 (L:D) photoperiod. Differences in head width among three temperatures of ${\approx}20^{\circ}C,\;25^{\circ}C\;and\;30^{\circ}C$ in G. paludum insularis, were compared. Temperature affected growth of head width of G. paludum insularis. There were highly significant differences among head width for three temperature regimes and the immature stages. It was found that head width is greater in $30^{\circ}C$ than $25^{\circ}C\;and\;{\approx}20^{\circ}C$. The growth quantity of the head width in ${\approx}20^{\circ}C$ shows the slowest increase, and $25^{\circ}C\;and\;30^{\circ}C$ were gradually increased in that order. The maximum ratio of growth quantity by each stage is in the first instar in all regimes. The growth rates of all regimes show an increase pattern.

• The Korean Journal of Ecology
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• v.14 no.4
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• pp.449-455
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• 1991

The water striders, gerris paludum insularis larvae which were fed with the drosophila melanogaster cultured on the appli diet and artificial diet, were reared in the growth cabinet controlled as the two constant temperature regimes of 25 c and 30 c under the condition of photoperiod 16l : 8d, light intensity 510 240 lux, relative humidity 65 3%, and in the natural state. The effects of temperature and diet on the devolopment of g. paludum insularis were analyzed and the results were summarized as follows. 1. The total developmental period of the water strider larvae fed with the d. melanogaster reared on the apple diet at the natural stste was the longest 40 days, and the total devopmental periods at 25 c and 30 c were 35 days and 27 days respectively. The tolal developmental period of larvae fed with d. melanogaster reared on the artifical diet at 25 c was the longest 42 dats, and the total developmental periods at natural stste and 30 c were 32 days and 27 days, respectively. 2. In the larval developmental stages, the fifth stage was longer than that of any stage. The duration of egg stage which was not influenced by diet at 25 c was the longest. 3. The water strider larvae fed which the d. melanogaster reared on the artificial diet at 25 c did not complete their devolopment. 4. No significant difference was odserved in the developmentperiod for diet at 30 c. but, there were significant differences in developmental periods for diet at 25 c and natural state. 5. The rate of adult emergence on the apple diet was higher than that of the artificial diet was higher than of the artificial diet. 6. The shapes of the survivorship curve were convex-curve. 7. The development periods of the larval stages of water striders might be affected to temperature and diet dependently.