Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2000
Publication Date: 6/1/2000
Citation: Knight, A.L., Unruh, T.R., Christianson Jr, B.A., Puterka, G.J., Glenn, D.M. 2000. Effects of a kaolin-based particle film on the obliquebanded leafroller, Choristoneura rosaceana (Harris), (Lepidoptera:Tortricidae). Journal of Economic Entomology. 93:744-749. Interpretive Summary: The obliquebanded leafroller is an important apple pest causing feeding injury on fruit. Management alternatives to the organophosphate insecticides are needed to effectively manage this pest. The effects of a kaolin-based particle film on the various life stages of obliquebanded leafroller in apple was examined in field and laboratory tests. Our studies showed that coating apple leaves and shoots with this inert clay coating reduces adult longevity and mating and egg laying by female moths. Egg hatch was not affected by the presence of the particles but larval growth rate and survivorship were reduced by the particle film coverage. Results from our field trials showed that an application of particle film to the dormant wood in March reduced the number of larvae feeding on trees later in the spring. However, particle film application had no affect on leafroller densities when applied after larvae were feeding inside rolled terminal leaves before and after bloom.
Technical Abstract: Studies were conducted in 1997 to evaluate the effects of the kaolin-based particle film formulation, M96-018, on adults, eggs, and larvae of the obliquebanded leafroller, Choristoneura rosaceana (Harris). Particle film treatments significantly reduced female longevity, mating success, and number of egg masses oviposited compared with moths on untreated apple leaves in sleeve cage and screened cage tests. No differences in mating success or oviposition were found due to the application rates and coverage density of M96-018 on foliage. Moths avoided ovipositing on particle film-treated leaves in choice tests. Egg hatch was not affected by topical application of or residual exposure to M96-018. Larval weight gain and pupal weight were significantly reduced and larval mortality increased in no-choice feeding tests with M96-018. In choice tests, larvae preferred to feed on untreated leaf surfaces. The negative effects on larval development and survivorship on M96-018-treated foliage did not differ across a 4-fold difference in spray application rate. A significant reduction in the number of infested shoots was found in orchard trials when M96-018 was applied before bud break in late March compared with untreated trees. No reductions in larval densities were found compared with an untreated control following pre-bloom and post-bloom applications.