Biological Performance of Potato Tuber Moth on Leaves of Tomatoes

Lowef population buildup of potato tuber moth (PTM) in tomatoes, when compared with potato, during vegetative growth period was observed. The present study was made to investigate on whether the lower PTM buildup in tomatoes was due to poor performance of PTM larvae on tomato leaves. Leaf feeding bioassays were carried out on three tomato cultivars in comparison with potato. Potato and tomato leaves were taken at preblossom and blossom plant stages and assayed under fully controlled condition. According to the results, the survival of PTM larvae reared on leaves taken at the preblossom stage was higher on cherry (87.5%) than other tomatoes and potato. Whereas, the survival on leaves taken at the blossom stage was higher on potato than tomatoes. Moreover, larval and larva-adult development times were significantly shorter on potato than tomatoes leaves at both plant stages. Therefore, the higher level of survival and significantly shortened larval and larva-adult development times on potato than the tomato leaves showed that tomato leaves were poor quality food source to the PTM compared with potato. Thus, the in-situ lower PTM population buildup on tomato leaves was attributed to poor performance of its larvae. Hence, any attempt to control the PTM on tomatoes should use this opportunity and focus on the post-flowering period.