Quick Facts, Southern Pine Beetle Biology and Control
John L. Foltz, Forest Entomologist
University of Florida, Dept of Entomology and Nematology
The southern pine beetle, Dendroctonus frontalis, is the most
studied of the southern forest insects. Below, in outline form, are some
essential facts gleaned from numerous articles and survey reports. Selected
references and links to additional web sites are listed at the end of the
document.
SPB Key Points
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Scientific name Dendroctonus means "tree killer"
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Mass attacks by thousands of beetles kill vigorous pines
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Beetles disperse widely and reproduce rapidly
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Community-wide detection and suppression programs reduce beetle impact
Benefits of community-wide suppression programs
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Reduced mortality of pine trees
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Reduced usage of protective insecticides
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Cost sharing encourages prompt control
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Cost sharing reduces the financial burden to individual property owners
Life Cycle
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Eggs hatch in less than 1 week
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Larvae develop in 2 weeks
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Pupal stage lasts about 1 week
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Females may live 1 month and lay 160 eggs
Behavior
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Females initiate attacks and produce aggregation pheromone
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Swarms of beetles can kill healthy pines
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Parents emerge in 1 week to disperse and infest additional pines
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Brood adults emerge in 4 to 6 weeks to disperse and infest new pines
Signs of Attack
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Popcorn-like pitch tubes on trunk of loblolly pines,
brown pitch-runs on slash and longleaf pines
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1-mm-diam holes in bark
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Serpentine egg galleries through the inner bark
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Pine needles changing from dark green to light green, to yellow, to red,
and
then falling to the ground
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Woodpeckers debarking stems of green pines
Epidemiological Factors of SPB Outbreaks
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Weather
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Insect Population Dynamics
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Forest Conditions
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Landscape Structure
Three Levels of Infestation
Factors Affecting Rate of Spot Growth
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Tree resistance
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Beetle numbers
Factors Affecting Tree Resistance
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Pine species
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Tree age, size, and growth rate
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Competition with other plants
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Weather
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Season of the year
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Trauma -- lightning, trenching, fire, thinning, etc.
Factors Affecting SPB Attacks/Day
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Distance to, size, and age of surrounding infestations
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Tree and beetle-produced attractants
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Tree and beetle-produced repellents
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Weather
Three Sources of Attacking Beetles
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Immigrant adults
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Reemerged parent adults
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Newly emerged brood adults
Suppression Objective
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To reduce SPB populations such that the number of attacking beetles is
unlikely
to exceed a tree's ability to resist colonization
SPB Control Options
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Cut and remove infested trees (Sanitation Salvage), then process logs to
kill beetles
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Cut and spray trees with approved insecticide
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Cut and leave (Spot Disruption) - does not stop beetle dispersal
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Do nothing
SPB Impact
1. Ecological Considerations
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Forest composition
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Fire hazard
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Wildlife habitat
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Insecticide side effects
2. Socio-economic Considerations
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Disruption of management plans
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Falling trees
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Property usage and value
Remedial/protective Insecticides
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Cut infested trees and spray bark to kill emerging beetles
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Spray healthy trees from crown down to ground
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Dursban 1% provides 2 - 4 months of protection
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Lindane 0.5% provides 3 - 6 months of protection
Preventing SPB Attacks during Outbreaks
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Support the quick detection and treatment of SPB-infested trees
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Promote tree vigor
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Avoid pruning and other activities that produce pine terpenes and attract
beetles
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Spray the base of trees attacked by the black turpentine beetle
Longterm Reduction of SPB Infestations
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Quickly detect and treat SPB spots
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Promote tree vigor
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Reduce forest susceptibility
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Increase spacing between pines
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Plant resistant hardwoods and less susceptible slash and longleaf pines
rather than loblolly pine
Selected References
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Meeker, J. R., W. N. Dixon, and J. L. Foltz. 1995. The southern pine beetle,
Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae).
Florida Dept Agric Cons Serv, Div Plant Industry Entomology circular No.
369. 4 p.
-
Thatcher, R. C., J. L. Searcy, J. E. Coster, and G. D. Hertel, eds. 1980.
The southern pine beetle. USDA Forest Service Technical Bulletin 1631.
265 p.
Additional information about the southern pine beetle can be found at:
Prepared by John L. Foltz,
19 Oct 1997. Last modified 4 June 2001.
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