Identifying the Injury. Oozing of sap and frass production on trunks are the most prominent indications of infestations. The sap often attracts flies, bees, wasps, butterflies, and other insects. Internal damage consists of extensive larval mining, often accompanied by discoloration and subsequent decay of the wood. About 3 weeks later, eggs hatch, and larvae tunnel directly into the wood.
New adults develop within the tunnels and emerge through a new, circular exit hole.
The life cycle requires 3 to 5 years for completion. Woodpeckers and sap ooze are the most important natural controls. Removing vines, which are good egg laying sites, may be cost effective when the wood is used for veneer. Vine removal operations should not damage bark, since this can actually encourage infestations. Photo by James Solomon Typical attack on white oak.