EFFECT OF TRIALEURODES-VAPORARIORUM (HOMOPTERA, ALEYRODIDAE) ON YIELD OF FRESH-MARKET TOMATOES

Effect of the feeding of immature greenhouse whitefly, Trialeurodes vaporariorum (Westwood), and sooty mold contamination on tomato production was determined using small field plots. Total and grade-A fruit weights harvested were correlated negatively with cumulative immature greenhouse whitefly days (=pest-days). Effects of T. vaporariorum feeding on tomato yield were influenced by environmental factors. Percentages of fruit contaminated with sooty mold were correlated positively with cumulative immature greenhouse whitefly days. Cumulative immature greenhouse whitefly days were correlated positively with peak immature whitefly densities during the growth cycle of the plant. Results suggest that tomatoes grown in Hawaii may incur a 5% yield loss in grade-A fruit at about greenhouse whitefly levels as low as 70 cumulative greenhouse whitefly days per cm2 tomato leaflet (=a peak density of 0.7 immature greenhouse whitefly per cm2 tomato leaflet per day) due primarily to the consumption of plant assimilates by T. vaporariorum. Compared with direct greenhouse whitefly feeding, contamination of fruit with sooty mold was less important with respect to reducing overall crop yields. A 5% reduction in grade-A fruit due to sooty mold contamination was estimated at almost-equal-to 300 cumulative greenhouse whitefly days per cm2 tomato leaflet (=a peak density of 8.3 immature greenhouse whitefly per cm2 tomato leaflet).