Hydraulic Spray Applications of Insecticides for the Control of Slash Pine Cone and Seed Insects.

摘要

Field spray tests were conducted from 1959 to 1961 in north Florida to evaluate the effectiveness of hydraulic spray applications of BHC, Guthion, and DDT for the control of coneworms, Dioryctria spp., and the slash pine seedworm, Laspeyresia anaranjada. Slash pines up to 40 feet in total height were protected from coneworm attack with BHC (4 lbs. gamma isomer/ 100 gal. water) or Guthion (1.5 lbs./lOO gal. water). DDT (4 lbs./ 100 gal. water) did not give satisfactory protection from coneworms. Of the three tested, Guthion was the only insecticide which controlled the seedworm. A spray schedule is given for the control of coneworms and the seedworm on slash pine in north Florida. Within the past decade in the South, large programs for the reforestation of idle and cut-over forest lands and the increased popularity of direct seeding have resulted in an unprecedented need for large amounts of pine seed. The tremendous expansion in forest tree improvement through genetics research has increased the demands for genetically superior seed. As of June 1963, a total of 4,674 acres of improved natural pine seed-production stands had been established on Federal, State, and private lands in 11 southern states. An additional 3,360 acres of pine seed orchards have been planted to produce the high quality seed of the future. It is not unusual in slash pine seed production areas for insects to partially damage or completely destroy from 50 to 70 percent of a cone crop, or 30 to 50 percent of the seed crop. If such areas are to produce a continuous, dependable supply of superior seed, they must be protected from the ravages of insects which directly or indirectly destroy the seeds.