Friday, May 20, 2011

Holes in pecan leaves

    If you walk through a pecan grove at this time of year, you are bound to find some new leaves riddled with irregularly shaped holes (photo at left).  These holes were created by the feeding of sawfly larvae.

    The sawfly is not a fly at all but actually a member of the wasp family. The green larvae of this insect are smalll (follow red arrow) and always feed on the underside of the leaf. Sawfly larvae look like caterpillars but have legs on every body segment (moth larvae have some body segments without legs).
     We monitor sawfly populations every spring checking for outbreak population numbers. In years past, sawfly populations have grown so large as to require a pesticide application. This year, the population numbers have remained relatively low and will not require treatment.