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Factors Limiting the Effectiveness of the Coccinellid Beetle, Adalia bipunctata (L.), as a Predator of the Sycamore Aphid, Drepanosiphum platanoides (Schr.)
A. F. G. Dixon
Journal of Animal Ecology
Vol. 39, No. 3 (Oct., 1970), pp. 739-751
Published by: British Ecological Society
Stable URL: http://www.jstor.org/stable/2864
Page Count: 13
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(1) Laboratory observations on the searching behaviour and efficiency in capturing aphid prey of the first instar larvae of the coccinellid beetle, Adalia bipunctata led to the suggestion that they would be unable to survive in the field unless the population density of young aphids on sycamore leaves exceeded two/100 cm2. (2) This minimum density value for survival of coccinellid larvae was confirmed by field observations from 1960 to 1968 on two sycamore trees where the intensity and success of predation by the coccinellid was related to the number of young aphids present. (3) The proportion of prey taken by the coccinellids in the field did not increase as the prey population density rose.
Journal of Animal Ecology © 1970 British Ecological Society