Factors influencing the pheromone trap catch of Phthorimaea operculella (Lepidoptera: Gelechiidae) in storage

Potato tuber moth (PTM), Phthorimaea operculella (Lep.: Gelechiidae) is a serious pest of potato, Solanum tuberosum (Solanaceae). To study factors influencing capture of male PTM by pheromone traps, two sets of experiments were conducted in a split-plot factorial design. In the first experiment, four factors were studied: potato cultivar (Agria, Marfona, Jelly, Arinda, Santea and Sabalan), storage type (cold and conventional), trap shape (funnel and delta) and trap color (white and green). Significant differences were found among storage types and potato cultivars. Total moth catches were eight times higher in conventional storage than that of cold storage. Agria and Marfona cultivars had the highest capture, while Arinda and Sabalan cultivars had the lowest. There were no significant differences between trap shapes and trap colors. Results showed that trap catches in different cultivars were affected by storage conditions. In cold storages the highest and lowest captures were 7.00 and 5.58 moth/trap/week, whereas in conventional storages the highest and lowest captures were 59.9 and 42.3. The second experiment was aimed to assess the effect of cellulose mulch on the capturing of PTM in conventional storages containing Agria. Results showed that pheromone traps in control (no-mulch) treatments caught three times more PTM than the mulched treatments. It is concluded that lower numbers of PTM were caught in potatoes held in cold storages than that of conventional storages. Otherwise, in conventional storages, cellulose mulch can be applied to reduce PTM population density.