Habitat quality and reproductive investment in aphids |
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Authors: | K F A WALTERS C BROUGH A F G DIXON |
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Institution: | School of Biological Sciences, University of East Anglia, Norwich |
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Abstract: | ABSTRACT. - 1 Genetically identical vetch aphids, Megoura viciae (Buckton), showed a weak but significant positive relationship between reproductive investment (number of ovarioles) and weight, here used as an indicator of habitat quality.
- 2 Apterae reared on poor quality plants showed the same range in numbers (twelve to twenty-two) but on average fewer ovarioles than those reared on high quality plants.
- 3 The variability in ovariole number was determined prior to birth.
- 4 Under constant conditions the age of a mother does not affect the range of ovariole numbers or the proportion of her offspring in each ovariole class.
- 5 Apterae reared on poor quality host plants gave birth to proportionately fewer offspring with a high ovariole number than apterae reared on high quality plants.
- 6 Winged individuals gave birth to proportionately more offspring with a high number of ovarioles than apterae.
- 7 The control and ecological significance of the intramorph variation in reproductive tactics shown by many species of aphids is discussed in the light of these results.
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Keywords: | Aphids habitat quality ovariole number maternal control reproductive investment |
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