Risk of Pine Beetle After Katrina

Questions keep arising concerning bark beetles following Katrina. Looking at history there has not been an outbreak of bark beetles following such events. It takes time for the bark beetles to respond to so much stressed and downed material. It is true that Ips will respond and be in the downed material as will many of the ambrosia beetles. The southern pine beetle doesn't utilize the wind thrown material. Of concern is increased susceptibility that depends on how stressed the trees are that are still standing. Recent history has indicated that two and three years after the event we have seen an increase in bark beetle activity, i.e. the southern pine beetle and Ips attacking standing trees. In particular are the trees with broken crowns or a few limbs missing. Also trees that are leaning and have suffered root trauma tend to be more susceptible in subsequent years.

This is a brief description of the situation.

Stands that have extremely low basal areas and well spaced are generally less desirable for the SPB. Even if beetles do attack a tree here and there spot growth is not of concern because of the residual stand configuration - trees hopefully well spaced, i.e. greater than 20 feet.

At present SPB in the state is at a very low level. There have been reports of more SPB activity in the Alabama counties bordering Mississippi and one should continue to look for signs of increased activity.

T. Evan Nebeker
Dept. of Entomology and Plant Pathology
Box 9775
Mississippi State University
Mississippi State, MS 39762
662-325-2984 (W) 662-325-8837 (FAX)