Southern Pine Beetle
The most important insect affecting loblolly pines in Maryland is the southern pine beetle, Dendroctonus frontalis. The southern pine beetle is a reddish brown-black insect smaller than a grain of rice. It attacks most species of pine, but most commonly attacks larger, mature stands of loblolly pine. This native insect occurs from Maryland south to Texas. Infestations are larger, more frequent, and cause more damage in States south of Maryland where winter temperatures are warmer.
Southern pine beetles often occur in small populations in pine forests, breeding in weakened or dying pines. Large losses occur when outbreaks develop following mild winters or hot, dry springs. During outbreaks, beetles can kill healthy trees by boring so many tunnels that the trees are girdled. Southern pine beetle management suppresses populations by quickly removing infested trees along with a small buffer of non-infested trees.
In Maryland, the most recent outbreak of southern pine beetles occurred in 1992-1993. Nearly 3,000 acres in Worcester, Wicomico, Somerset, and Dorchester counties and over 25 million board feet of loblolly pine were affected. However, the cold winter of 1993-1994 lowered populations to the point that southern pine beetles were not a problem in the summers of 1994 and 1995.