Survivorship and Fertility Schedules of Two Epilachnine "Species" Feeding on Cucurbitaceous Plants under Laboratory Conditions (Coleoptera : Coccinellidae)
1984 年 19 巻 1 号 p. 59-66
詳細
1984 年 19 巻 1 号 p. 59-66
Two "species" of Sumatran epilachnine beetles, which are similar to Henosepilachna sparsa DIEKE, were reared under laboratory condition to study their survivorship and fertility schedules. The "species C" fed on bitter cucumber and "species D" on squash. The mean longevity of the males (70.5 days in sp. C and 88.6 in sp. D) was longer than that of females (63.8 days in sp. C and 63.9 in sp. D). The mean length of the pre-reproductive period (18.9 days in sp. C and 15.5 in sp. D) was longer than that of post-reproductive period (4.0 days in sp. C and 5.2 in sp. D). The females of the two species laid eggs at a nearly constant rate throughout their reproductive period. The reproductive value Vχ/V0 of the two species remained at high level for most of adult life, resulting from the prolonged survivorship and fertility schedules. The total number of eggs produced per female was 651.9 (sp. C) and 763.8 (sp. D). The intrinsic rate of natural increase γwas 0.10 (sp. C) and 0.12 (sp. D) per capita per day. The demographic taits of these Sumatran species are discussed in comparison with temperate species.
