Department of Bio-Sciences, Himachal Pradesh University, Simla
Life history and reproductive behaviour of virginoparae of woolly apple aphid were studied in summer and winter seasons. These undergo four moults resulting in five instar stages. The pre-reproductive and reproductive periods are longer in winter as compared to summer. However, fecundity rate is high in summer as compared to winter. During summer, maximum infestation occurs on the aerial parts while in winter roots are attacked severely. Migration of woolly apple aphid from roots to shoots in summer and viceversa in winter is observed, No nymphal hibernation occurs in winter months. Alate sexuparae appear from late July to November and these produce sexuals.
