Dispersal of first instar larvae of the felted beech scale, Cryptococcus fagisuga.

Published online
01 Jan 1981
Content type
Journal article
Journal title
Journal of Applied Ecology

Wainhouse, D.

Publication language
UK & Great Britain & England


Dispersal of Cryptococcus fagisuga Ldgr. in a beech forest in southern England was studied using suction traps and sticky traps. First instar larvae and eggs of C. fagisuga had mean terminal falling velocities of about 27 cm/s and 40 cm/s respectively. The larvae were the main dispersive stage and were carried passively downwind from infested trees. In mean windspeeds of <1 m/s larvae dispersed a mean distance of about 10 m from a source tree which was infested from near ground level to the lower canopy. The distance dispersed was proportional to height of take-off and windspeed. In suction traps sited from 1 m above the ground to 6 m above the canopy (18 m above the ground) most larvae were trapped at 1 and 3.2 m above the ground; about 0.7% were trapped at or above the top of the canopy. The larvae dispersed along a short-range steep gradient under the canopy and a potentially long-range shallow gradient above the canopy.

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