Enemy-free space and the feeding niche of an aphid
1997
Hopkins, G.W. | Dixon, A.F.G.
1. The nymphs of the aphid Monaphis antennata occupy an unusual feeding niche, being restricted to the upper surfaces of leaves and petioles. The possibility that this is a predator-avoidance strategy was investigated. 2. Nymphs could be induced to feed on the under surfaces of petioles and the mortality of these nymphs was then compared with the mortality of nymphs feeding from the upper surfaces when exposed to coccinellid predators. 3. Coccinellid larvae spent less time foraging on the upper surfaces of leaves and petioles than on the under surfaces of leaves and petioles. 4. The nymphs occupying the upper surfaces of petioles, the normal feeding position, were encountered by the coccinellids later and less often, and fewer were attacked compared with those occupying the under surfaces. 5. It is concluded that the feeding niche of the nymphs of this aphid is adaptive in that it reduces exposure to foraging predators and is the result of selection to occupy enemy-free space.
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