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Aerial surveys during the spring and summer help foresters locate new spots and are used to monitor the spread of larger ones such as this infestation located in the Alligator River National Wildlife Refuge. Nearly 45 acres in size, this spot not only poses a great threat to the pond pines that dominate the landscape, but it threatens animals like the red cockaded woodpecker that depend on mature live trees for nesting sites. Dominated by a forest type which boasts the highest fuel load in the United States, large areas of dead timber pose a tremendous fire hazard in the refuge.
This spot was flown in Late June 1996. The gray area indicates dead pines that have dropped their needles. The red trees are considered stage 3 trees and have already been vacated by SPB at this time. The yellow trees, or "faders", are considered stage 2 trees and contain developing brood (larvae, pupae, and brood adults). Generally, there are as many green-infested trees, or stage 1 trees, as there are fading (yellow) trees. This spot is considered a multi-headed spot. Such spots by nature are extremely difficult to control. This spot will probably continue to grow until Ocotber, when cooler temperatures forcibly slow SPB activity.
Open wilderness areas such as the one pictured here make it difficult for ground control crews to suppress infestations via silvicultural methods. Under these constraints, alternative control measures must be undertaken. Field research has demonstrated the ability of the verbenone suppression tactic to slow or stop the expansion of small spots in the refuge before they reach an unmanageable size like the one pictured here.