Comparative Life-History Studies of Nearctic and Palearctic Populations ofCoccinella septempunctata(Coleoptera: Coccinellidae)
作者:
Mpho W. Phoofolo,
John J. Obrycki,
期刊:
Environmental Entomology
(OUP Available online 1995)
卷期:
Volume 24,
issue 3
页码: 581-587
ISSN:0046-225X
年代: 1995
DOI:10.1093/ee/24.3.581
出版商: Oxford University Press
关键词: Coccinella septempunctata;local adaptation;geographic variation
数据来源: OUP
摘要:
Life-history characteristics of four populations ofCoccinella septempunctataL. were quantified and compared at 26°C and 18:6 (L:D) h on a diet of pea aphids,Acyrthosiphon pisum(Harris). Populations were from two locations in the United States (Iowa and Delaware)and two locations in Eurasia (France and Ukraine/Moldavia/Crimea). Large intrapopulation variation was observed in preoviposition, interoviposition, and number of days on which eggs were laid. This variation was a result of 10–35% of females entering diapause, whereas most females initiated oviposition within 12 d of eclosion an continued egg laying with interoviposition periods of<6 d. No significant differences among the four populations were detected in preoviposition, interoviposition, or number of days on which eggs were laid. In addition, preimaginal development time, sex ratio, and life table parameters, including intrinsic rates of increase and fecundity, did not differ significantly among the four populations. On the basis of the parameters measured, we conclude that these four populations of C.septempunctatahave not undergone local adaptation that would define these populations on the basis of geographical origin.
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