Studies in the distribution of insects by aerial currents. III. Insect drift over the sea

Aerial samples caught in nets slung from ships mastheads contained predominantly small, weak‐flying insects. From over 102 trips with a total sailing time of over 1151 h, some 1825 insect specimens were collected. In a specified area over the North Sea more than 160 km from land (seventy‐five samples), catches averaged 1 insect h −1 ; in the English Channel, in a smaller area more than 80 km from the coasts, hourly catches averaged 4 insects h −1 . Lists of orders, families, genera and species caught are appended. Aphids, which constituted more than 60% of the total, apparently originated mostly from the west or north‐west, i.e. from Europe, whereas most other insects seem to have originated from the north‐east and south, i.e. from Britain. These data have implications for the spread of agricultural pests to and from Britain.