Dispersal mechanisms in an intertidal aphid

• Published in: The Journal of animal ecology Vol. 47; no. 1; pp. 205 - 217
• Main Authors: Foster, W.A, Treherne, J.E
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Scientific Publications 01-02-1978
• Subjects: arthropods; Buoyancy; entomology; Erosion; insects; Instars; Marshes; Pemphigus; Plants; Salt marshes; Sea water; Soil erosion; Water erosion
• DOI: 10.2307/3932
• EISSN: 1365-2656
• ISSN: 0021-8790

(1) The instability of the edge habitat of the saltmarsh aphid (Pemphigus trehernei Foster) necessitates effective means of dispersal. Experiments show that colonization of sea asters in low marsh areas is rapid and thorough. (2) A significant proportion of submerged aphids are released to the surface during tidal erosion of edge soil and could contribute to a `catastrophic dispersal' of adult and immature stages. (3) First instar larvae are released from edge soil during non-eroding tidal coverage. This instar is well adapted for floating and can survive for long periods on water surfaces. (4) Experiments with aphid models show that such small floating objects are moved over wide areas under the combined influence of wind and water movements. A significant proportion were deposited at the high tide mark, in the vicinity of aster plants, by the first few submerging tides following tidal emergence of the saltmarsh. (5) Colonization of aphid-free aster plants in the field indicates that movement on the tidal surface is an important dispersal mechanism for this intertidal insect.