Differential Response of Potato Tuber Moth and its Parasitoids to Different Solanaceous Hosts: Implication to PTM Management in Tomatoes

Abstract

Potato tuber moth is an oligophagous pest of different solanaceous crops. The present study evaluated the potential of intercropping tomato with other solanaceous species as trap crops in safeguarding tomatofrom PTM damage. Paired potato, wild solanum, eggplant, tobacco, and tomato were caged open in the field as sole and mixed species and also planted in the open as sole and mixed crops. The paired plants were artificially inoculated with four mated females. The open field grown plants were left for natural infestation. The leaves of the different solanaceous species were inspected once a week for PTM larvae presence and level of parasitism was also determined in the lab. In the cage experiment, unlike for same species paired; there was a significant difference in PTM larva density for each paired species and the lowest larval density was in tomato. Whereas in the open field, the number of recovered larvae on eggplant and tomato was significantly lower than on the other species. In the field cages, Diadegma mollipla (Holmgren) release in the field cage parasitized larvae only on the leaves that were present potato, wild solanum, and eggplant. Similar results were obtained in the open field. Unidentified parasitoid was recorded on tobacco leaves of tobacco in the open field. The results illustrate that presence of potato, tobacco, eggplant or wild solanum present in the proximity of tomatofield would serve as trap plant for PTM and its parasitoids and help reduce damage to tomatoes fruits.