The nymphs in the photo are the immature form of the citrus flatid planthopper (Metcalfa pruinosa). Adult planthoppers are small, gray, wedge-shaped insects that spring off the stems of trees when disturbed (photo below). Nymphs are wingless and remain clustered in a group until they reach maturity. Both nymphs and adults are sap feeders, piercing the bark of young trees to feed.
The ants in the photo are tending the planthopper nymphs. They collect the sugar-rich honeydew secreted by the planthoppers while protecting the nymphs from predators and parasites.
Planthopper feeding does not pose a serious threat to young pecan trees. Although a large white patch on the stem of a young tree may look bad, an insecticide treatment is not necessary.
|Adult citrus flatid planthopper feeding on young pecan tree|