by Justin Cook

Created on: January 18, 2007   Last Updated: May 02, 2007

"A Study of the Southern Pine Beetle"
The Southern Pine Beetle (SPB), Dendroctonus frontalis Zimmerman, is the number one killer of pine trees in the South. Across the South, from Virginia, south to Florida, and west to Texas, pine trees are numerous and in most of the southeastern United States they are the dominant tree species. Recent damage assessments estimate that from 1960 to 1990, SPB has caused in excess of $900 million of damage to pine forests. SPB makes its home in the inner bark layers of pine trees and ultimately kills its host tree. The biology of D. frontalis has been much studied because of their damaging effects on the paper and lumber industries and also because it is part of the reason why Red-cocked woodpecker populations are on the decline. The purpose of this paper is to explain the biology of SPB and elaborate on the impact that SPB has had and has on the southern environment. As more and more woodland is cleared for more and more people, it becomes increasingly important that we find ways to protect all the forests that we are able to. It is important that all the artificial stands of planted pine forests be spared from SPB infection, as artificial forests take pressure off of natural forest harvesting. By understanding the biology of SPB we can hope to prevent further insect-related tree damage.

The Southern Pine beetle makes it home in the cambium of pine trees. SPB most commonly attacks weakened species of Pinus taeda (loblolly), Pinus echinata (shortleaf), Pinus virginiana (Virginia pine), and Pinus rigida or (pitch pine). Pine beetles are exuded from species such as slash, longleaf, and eastern white pine because they have a high resin exudate that "pitches out" burrowing beetles better than other pines. Pine beetles are active all year, and are most abundant in the warmer months of spring summer and fall. SPB is a dark black or brown beetle, and is about 2-5mm long.The SPB is capable of rearing up to seven generations per year. The SPB begins it's life cycle when a female "pioneer beetle" lights midway up a tree, (10-30 ft. up), and bores into the bark. The SPB appears to select mature trees through random landings. As a female bores her way into the bark, a semiochemical is released from her hindgut. As she makes her way into the tree the aggregation pheromone, frontalin, is released. The feces of SPB or "frass," contain large amounts of frontalin. "Frontalin plays a dual role as both a sex pheromone and aggregation pheromone."

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