Control of a Serpentine Leafminer on Chrysanthemum Under Greenhouse Conditions, Winter, 1995

Abstract

Abstract Chrysanthemums were obtained as rooted cuttings and potted in 15 cm pots in a greenhouse at UCR and allowed 4 wk growth (20-25 cm tall) before use. During week four, Marathon 1G was applied as a soil treatment and drenched into the soil with approximately 250 ml of water. One week later, plants were assigned to treatments prior to leafminer exposure. All plants (six replicates per treatment) were exposed to an existing leafminer colony for 2 h. Pre-treatment counts and remaining spray applications were made four days after leafminer exposure. Spray applications were made using a hand sprayer at 30-40 psi. When the plants were dry, they were tipped over trays filled with sand. Pupae dropped into the trays and the sand was sifted to collect them. Pupae were held in an environmental chamber until all adults had emerged (12 days). Post-treatment counts were then made of the number of pupae and emerging adults. Data were expressed as a mean percent mortality from the pre-treatment count and analyzed using ANOVA. One replicate of the control had an unusually high mortality rate. This replicate was removed as an outlier prior to analysis (Sokal and Rohlf 1981, Dixon 1950).