Effects of Kaolin Particle Film on the Viburnum Leaf Beetle During Container Production of Viburnum dentatum under Different Levels of Nitrogen Fertilization1

We investigated two pest management strategies for Pyrrhalta viburni (Paykull), a non-native leaf beetle that has invaded New England and is defoliating susceptible wild and cultivated species of Viburnum. SurroundWP (kaolin wettable powder) was tested as a barrier spray during container production of V. dentatum, to determine if it would affect P. viburni leaf damage, oviposition and plant growth. The effect of added N (nitrogen) was also tested. SurroundWP significantly lowered leaf damage and numbers of egg masses in amended plants, without a negative effect on plant growth. Nitrogen use significantly increased leaf damage by adults, numbers of egg masses, and plant growth. These results suggest that commercial growers of susceptible Viburnum species in areas where P. viburni is found could benefit from the use of SurroundWP, and that N amendment should be kept to a minimum.