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Survivorship and fertility schedules of two Sumatran tortoise beetles, Aspidomorpha miliaris and A. sanctaecrucis (Coleoptera: Chrysomelidae) under laboratory conditions
Author(s) -
Nakamura Koji,
Abbas Idrus,
Hasyim Ahsol
Publication year - 1989
Publication title -
population ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 59
eISSN - 1438-390X
pISSN - 1438-3896
DOI - 10.1007/bf02515803
Subject(s) - survivorship curve , biology , fecundity , reproductive value , biological dispersal , fertility , tortoise , longevity , morning , shrub , zoology , reproduction , ecology , botany , demography , population , offspring , pregnancy , genetics , cancer , sociology
Summary Two species of tortoise beetles, Aspidomorpha miliaris (AM) and A. sanctaecrucis (AS) feeding on a shrub‐like morning glory, Ipomoea carnea , were reared under laboratory conditions to study their survivorship and fertility schedules. AM and AS required 34–39 days and 30–37, respectively, for the development of the immature stages. The mean longevity of the males was 88.4 days in AM and 63.8 in AS, and that of females was 87.9 days in AM and 83.3 in AS. The mean length of the pre‐reproductive period (27.2 days in AM and 33.8 in AS) was much longer than that of the post‐reproductive period (10.9 days in AM and 14.3 in AS). Females laid eggs at a nearly constant rate throughout their reproductive period. The reproductive value V x / V 0 of the two species remained high for most of their adult life, as a result of prolonged survivorship and fertility periods. The total number of eggs produced per female was 442.9 (AM) and 80.1 (AS). The intrinsic rate of natural increase r was 0.070 (AM) and 0.044 (AS) per capita per day. The prolonged reproductive schedules, coupled with strong dispersal power, of these species no doubt have an adaptive value for living in highly disturbed tropical environments, where rainfall is ample but unpredictable and food resources are available throughout the year in a wide area, but distributed in widely flung patches.