Aspects of Aphid Overwintering (Homoptera: Aphidinea: Aphididae)
Leather, Simon R.
The overwintering strategies of holocyclic and anholocyclic aphids are discussed. The magnitude of the mortality likely to be experienced by eggs (70 %) and viviparae (up to 100 %) is compared and contrasted and the factors determining this listed. It is concluded that natural enemies; birds and arthropods, are the major factors causing aphid egg mortality and that low temperatures are the greatest single cause of mortality affecting viviparae. Three systems predicting aphid numbers on summer crops, based on winter populations of aphids are described and assessed as to their usefulness.