Effect of application of organic fertilizers in growing medium of potato plants on biological characteristics of Phthorimaea operculella (Lepidoptera: Gelechiidae)

Potato tuber moth, Phthorimaea operculella Zeller, is one of the important pests of potato, causing damage on leaves, stem, and tubers. Type of fertilizer may affect the population of the pests feeding on the plant. In this study, the effect of some organic fertilizers including vermicompost, humic acid, a mixture of vermicompost and humic acid, and nanocomposites bio-organic was investigated on biological traits of potato tuber moth. The experiments were carried out on potato leaves, cv. Agria in a growth chamber. Results showed that nearly all the biological parameters of potato tuber moth were significantly affected by fertilization. The shortest larval period was in the control and the longest one was on humic acid and nanocomposites bio-organic. The longevity of the males ranged from 10.21 to 18.68 days and that of females varied from 12.94 to 23.20 days on different treatments. The females of the pest had the least total fecundity on humic acid. The intrinsic rate of natural increase (rm) of the potato tuber moth ranged from 0.096 to 0.119 day-1 on different treatments. Counting the number of trichomes of the leaves of different treatments showed that the highest density of trichomes was on humic acid. The results of this study showed that humic acid has better potential for decreasing the population of the pest and it can be used in the IPM programs.