SPB & Invasive Insects - What are SPB?
The southern pine beetle, Dendroctonus frontalis , is the most important pest of pine forests in the southern US, generating an estimated $901.8 million in damage in the period from 1960 to 1990 (Price et al. 1992). More recently, losses in 1995 alone were estimated to be $350 million (USDA Forest Service 1995). In common with other "aggressive" bark beetles, D. frontalis is able to mass attack and kill living trees. Favored hosts include the loblolly pine, Pinus taeda , and shortleaf pine, P . echinata (Payne 1980). The mass attack process is initiated by adult females, which bore into the tree and release pheromones that in combination with volatiles from the damaged tree attract large numbers of beetles. If a sufficient number respond they overwhelm the defenses (the resin system) of the host tree, and then attack is switched to adjacent trees (Payne 1980). Active fronts of trees under attack often form in larger infestations, and if untreated they can expand to cover thousands of acres.
Outbreaks of southern pine beetle occur at regular intervals of 7-10 years in some locations. Time-series analysis suggests that these cycles in southern pine beetle abundance are not caused by fluctuations in weather, but instead are driven by some unknown process acting with a time delay (Turchin et al. 1991), possibly natural enemies or fungal competitors.
For further information on the biology of southern pine beetle, and control methods, see the Southern Pine Beetle Information Directory .
References Cited
Payne, T. L. 1980. Life history and habits. Pages 7-28 in R. C. Thatcher, J. L. Searcy, J. E. Coster, and G. D. Hertel, editors. The southern pine beetle. USDA Forest Service Technical Bulletin 1631.
Price, T. S., C. Doggett, J. M. Pye, and T. P. Holmes. 1992. A history of southern pine beetle outbreaks in the southeastern United States. The Georgia Forestry Commission, Macon, Georgia. 61 pp.
Turchin, P., P. L. Lorio Jr., A. D. Taylor, and R. F. Billings. 1991. Why do populations of southern pine beetles (Coleoptera: Scolytidae) fluctuate? Environmental Entomology 20: 401-409.
USDA Forest Service. 1995. Forest Insect and Disease Conditions in the United States, 1995. Forest Pest Management, Washington, DC.