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Chilades pandava peripatria Hsu and its host plant Cycas taitungensis Shen, Hill, Tsou & Chen are both endemic species to Taiwan. Ch. pandava peripatria has a specific association with buds and soft leaves of cycad plants. The introduced species, Cy. revoluta, have prolonged budding periods and extensive auxiliary buds that extensively contribute to the outbreak of Ch. pandava peripatria. An in-depth knowledge of the development, survival, and fecundity of Ch. pandava peripatria under different environmental conditions is necessary to understand the population growth of Ch. pandava peripatria. The demography of Ch. pandava peripatria was studied based on the age-stage, two-sex life table at 20, 23, 25, 28, and 31 degrees C, 70% RH, and a photoperiod of 16:8 (L:D) h under laboratory conditions. Ch. pandava peripatria completed its development under tested temperatures but did not produce offsprings at 23 degrees C. Because of the high egg mortality at 20 degrees C, the data at this given temperature were excluded from this study. The intrinsic rate of increase (r) under these tested temperatures was 0.1846, 0.2919, and 0.1412 d(-1), respectively. The net reproductive rate (H(o)) was 165.47, 262.32, and 56.68 offsprings per individual and the mean generation time (T) was 27.72, 19.10, and 28.67 d, respectively. Our results indicated that Ch. pandava peripatria is highly adaptable to environments where temperature ranges from 25 to 31 degrees C.

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Foliar chemicals are variable within a plant and this may affect herbivore feeding preference. This study was carried out to quantify concentrations of primary (nitrogen, water, and total nonstructural carbohydrates) and secondary substances (sinigrin) in young and old leaves of Raphanus sativus L. and to evaluate performance and survival of a generalist herbivore Spodoptera litura F. feeding on them. Forty to 50-d-old R. sativus plants were used in both foliar chemical analysis and insect performance bioassays. Leaves located on the third to the sixth node from the base of the plant were defined as old leaves and the remaining leaves (from seventh node to the plant apex) of the plant were referred as young leaves in this study. All foliar chemicals except water differed significantly between young and old leaves. Moreover, young leaves were more nutritious but much more defended, based on sinigrin content, against S. litura than old leaves. Performance and survival of S. litura were reduced on young leaves as compared with old leaves. Male and female larval duration only differed significantly on young leaves. Female larval development time was longer than male development time on young leaves, but not on older leaves. Therefore, this study revealed that defenses in young leaves have differential effects upon male and female S. litura.

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