Beetles and Beetle Damage

WHITEFRINGED BEETLE ADULTS AND LARVAE - The larvae of whitefringed beetle cause significant damage to sweet potatoes. These pictures present the larvae and adult stage. The damage on the sweet potato is typical of the damage the larvae cause. There is apparently one life cycle/year in Louisiana. The adults begin to emerge in May or June and can begin to lay eggs within a couple of weeks after emerging. This is an interesting insect in that all are females. They can lay eggs without mating. SEVERE WHITEFRINGED BEETLE LARVA DAMAGE ON SWEET POTATO ROOTS - Our strategy and recommendations for reducing the damage caused to sweet potatoes by this insect is to try to control the adult after she emerges. None of the preplant insecticides labeled for sweet potatoes control the larvae. Recommendations call for foliar application of Imidan 70WS at the rate 1 1/3lbs/a or Penncap M at 2 pints/a beginning soon after transplanting. There is some indication that applications of these insecticides should be made to fields that haven’t been planted, especially in mid-late June and July. This is an attempt to control the adult beetle before she starts laying eggs. The eggs laid at this time develop into the larvae that cause the damage on the roots. Read and follow the pesticide label instructions carefully.

SUGARCANE BEETLE ADULTS SUGARCANE BEETLE DAMAGE ON SWEET POTATO ROOTS.