Feeding Site of Palomena angulosa MOTSCHULSKY (Hemiptera : Pentatomidae) on Potato Plants and Injury Caused by the Feeding

Abstract

The bugs Palomena angulosa MOTSCHULSKY sucked plant sap from the leaf vein and petiole of the potato plant at significantly higher frequency than from the stem. On the leaf, adults tended to take the plant sap from the midrib more willingly than from the lateral vein, whereas nymphs more frequently sucked sap from the lateral vein. It was also observed that the 3rd instar nymphs fed on the flower bud. Twenty-one percent of the bugs fed at the tip (growing) part of the plant. Almost all completed feeding within 30 min, though starvation prolonged their feeding time. Above the feeding point the plant began to wilt 1 to 7 days after the infestation and withered when the attack was severe. Histological observation showed that the insects usually sucked plant sap from the phloem tissue resulting in destruction of the phloem and occasional plugging of neighboring xylem with sheath material.