Evaluation of Sevin and Lorsban for Thrips Control on Citrus During Bloom, 1996

Two Sevin formulations were compared against Lorsban for controlling adults and larvae of Frankliniella bispinosa. Treatments were assigned to 8 rows wide X 12 trees/row ( = 96 tree) to 8 rows X 13 to 21 trees/row (= 150 tree) plots in a RCB design, replicated 4 times on 12-18 ft tall trees with 15 X 25 ft spacing. Treatments were applied on 25 and 26 Mar using a Rears PTO airblast sprayer with speed, nozzling and pressure adjusted to apply 200 gpa. At each evaluation date, 20 open flowers were randomly collected from at least 5 trees in the center of each replicate. Each flower was picked individually and placed immediately in a one pint jar containing ca. 100 ml of 70% ethanol. The jars were returned to the laboratory and the number of open flowers were recorded per jar. Individual flowers per jar were teased apart to expose and flush thrips motile stages from the areas between petals, filaments and the pistil. The numbers of both F. bispinosa adults and larvae per 20 open flowers were recorded as one observation. Data were subjected to log10 (X + 1) transformations for statistical analysis and untransformed means are presented in the tables for comparison.