Host Plants and Abundance of Thrips palmi Karny (Thysanoptera: Thripidae), an Important Pest of Vegetables in Southeast Asia

Abstract

Field surveys were conducted to determine vegetable crops infested with Thrips palmi as host plants in Thailand, Malaysia and the Philippines in 1987 and to estimate the abundance of this thrips on different vegetable crops in Thailand in 1987-1988 and in Malaysia in 1987. T. palmi was found attacking angled loofah, bitter cucumber, cucumber, eggplant, goat pepper, muskmelon, pumpkin, squash, watermelon, wax gourd, yard long bean, two species of Phaseolus and one unidentified Cucurbitaceae. Of these crops, eggplant appeared to be most commonly infested with the thrips. The abundance of T. palmi on eggplant in Thailand appeared to be influenced by the weather, pesticide applications and fruit type. Heavy rainfall during the rainy season may be responsible for greatly reduced populations of T. palmi on eggplant. On the other hand, the high abundance of T. palmi observed in truck gardens growing a long fruit eggplant in the dry season may have been induced by destruction of natural enemy and competitor populations from heavy insecticide use.