Laboratory Evaluation and Ranked Preference Assessment of Subterranean Termites Coptotermes Formosanus Shiraki (Isoptera: Rhinotermitidae) on Pecan Cultivars of Carya Illinoinensis (Wangenh.) K. Koch in Texas

Abstract

Feeding preferences of Coptotermes formosanus Shiraki were evaluated on 60 field-collected pecan Carya illinoinensis (Wangenh) cultivars. The Moneymaker cultivar of C. illinoinensis was most preferred by C. formosanus, and the degree of feeding on this cultivar was significantly different (P < 0.05) from all other cultivars tested. Creek was the least preferred cultivar, but the degree of feeding was not significantly different from other cultivars. There was a trend for lower consumption by C. formosanus on commercially versus native cultivars. In a multiple-choice test, the Desirable pecan cultivar, was significantly (P less than 0.05) more preferred than southern yellow pine (Pinus palustris), chinaberry (Melia azedarach), and the pecan cultivar, Barton, respectively. The significance is that Formosan termites fed on both pecan cultivars and southern yellow pine which is a commercially important wood. They also fed on chinaberry, which is a commonly used tree in landscape. Coptotermes formosanus were significantly (P less than 0.05) more attracted to green leaf material from the Creek cultivar as compared to the other 50 cultivars tested. However, the Creek cultivar was the least preferred in the consumption test. This suggested that Formosan termites may be attracted to pecan trees and chemicals associated with the wood. It is evident that Formosan termites feed on various types of pecans in agro-ecosystems, this may be attributed to leaf characteristics as well as other factors such as random foraging and swarming behavior. These results further demonstrate that pecan cultivars are at risk to C. formosanus feeding.