The development of a sampling system for monitoring population levels of the woolly apple aphid, Eriosoma lanigerum (Hausmann), in apple orchards in the Western Cape Province of South Africa

Pringle K.L. ; Heunis J.M. (2008)


A sampling system was developed for monitoring population levels of woolly apple aphid, Eriosoma lanigerum (Hausmann), by counting colonies on half of each of 25 apple trees per 2 ha block. Sampling error was affected by whether the colonies were found in wounds or in leaf axils. Parasitism of colonies in leaf axils had a slight effect on sampling error. Sampling error for colonies in leaf axils was high at just over 40 %. However, decisions regarding intervention were not markedly compromised by simply classifying the 25 trees as infested or uninfested, as opposed to counting colonies in leaf axils. The presence-absence system greatly reduced the time spent monitoring E. lanigerum population levels, making it an attractive system for assessing woolly apple aphid infestations in commercial orchards.

Please refer to this item in SUNScholar by using the following persistent URL:
This item appears in the following collections: