Developmental changes of peach-potato aphid (Myzus persicae Sulz.) under higher temperatures - the importance of a new phenomenon in the integrated protection of potato

摘要

The temperature, photoperiod and nutritional quality of hostplants are the main factors affecting the emergence of sexual forms of aphids. Under certain conditions they can induce changes in the biology of aphids, which so far exhibited holocyclic development, for instance the peach-potato aphid (Myzus persicae Sulzer, 1776). Among the economically important species of aphids, this is particularly important, mainly as a vector of viruses in potatoes. In recent years the flights of this species have been registered in suction trap much longer than previously and the lack of males indicated that they may be mainly the anholocyclic forms. In parallel studies conducted in the environmental chambers, a cessation of the development of male and female egg-laying was detected as the effect of higher temperatures occurring under identified conditions of the photoperiod. As a result of this new phenomenon in the development of aphids an increase of their harmfulness is expected and not only in regards to viral diseases but also as a direct harmfulness, caused by new forms of development of this species. Knowledge of the phenomenon, combined with constant control of the plantation and monitoring mean daily temperatures are one of the basic elements of integrated protection of potato cultivation against M. persicae.