Epizootic of White Halo Fungus, Verticillium lecanii (Zimmerman), and Effectiveness of Insecticides on Coccus viridis (Green) (Homoptera: Coccidae) on Coffee at Kona, Hawaii

摘要

Efficacy of Volck oil, Superior 70 oil. Mavrik Aquaflow (fluvalinate), and Safer's insecticidal soap against Coccus viridis (Green) was studied on coffee at Kona, Hawaii. No scales were found on Mavrik treated trees 20 days after treatment. Scale populations decreased on Volck oil, Superior oil, and Safer soap treated trees to levels significantly below controls at 28 days after treatment. Scale populations recovered to control levels by 106 days after treatment on all trees treated with oil or soap. C. viridis populations never recovered from the Mavrik treatment. C. viridis caused significant stunting of coffee trees when not controlled. Mavrik treated trees were significantly taller than all other trees. An epizootic caused by the fungus Verticillium lecanii (Zimmerman) decimated C viridis populations on all sampled trees. Fungus-infected scales first appeared ca. 2 weeks after the beginning of increased precipitation. The regression of percent fungus-infected scales with percentage of days with rain 2 weeks prior to the sample date was significant.