RED IMPORTED FIRE ANT (HYMENOPTERA, FORMICIDAE) - CORRELATION OF ANT DENSITY WITH DAMAGE TO 2 CULTIVARS OF POTATOES (SOLANUM-TUBEROSUM-L)

Red imported fire ants, Solenopsis invicta Buren, damaged 12.2-26.1% of ''Sebago'' and ''Russett'' potatoes(Solanum tuberosum L.) in small-plot field tests in 1983-1985 and caused severe damage to commercial plantings of potatoes in the Hastings area of northeastern Florida [USA]. The extent of potato loss in both small plots and commercial fields was positively correlated with numbers of ants caught per bait trap. Average numbers of ants trapped varied from 2 to 205 per bait. The United States Standards for Grades of Potatoes define severe damage as that which results in the loss of > 10% of the total weight of the potato; our data indicate severe damage occurs when the average ant catch per trap exceeds 80. This information can be useful to growers for determining when costs of ant control are economically feasible.