Host Status of Meyer and Eureka Lemons for Anastrepha ludens

Abstract

Host status for Mexican fruit fly (Anastrepha ludens (Loew)) was examined under laboratory conditions in cage infested Eureka and Meyer lemons. Our approach was to allow females to oviposit on the two cultivars in separate laboratory cages with aluminum foil covering to restrict the areas where females had access to fruit surface. Fruit of each cultivar were placed in covered trays for incubations and at approximately weekly intervals, fruit were removed, dissected, and live and dead eggs and larvae tabulated in each tissue of the fruit. Infestation and survival were tabulated and analyzed for the effects of harvest date, fruit color and brix indices, postoviposition period, and cultivar. Infestation rate, determined by counts of total eggs and larvae was significantly higher in Meyer lemons. In both cultivars, females deposited eggs into both albedo and pulp tissue but not into flavedo. Both cultivars showed high resistance (> 90% mortality) to egg and first instars survival in albedo and pulp. Second and third instars surviving in the pulp had high survival rates (> 60%) in both cultivars in fruit dissected at weeks 2-4 after infestation. Total adults produced were slightly higher, and total second and third stage larvae were also higher for Meyer lemons. Numbers of adults and total second and third stage larvae increased in Eureka lemons in more mature fruit, but the higher numbers in Meyer lemons were not associated with fruit maturity, at time of infestation. Numbers of second and third stage larvae were significantly correlated with some fruit color indices in Eureka but not in Meyer lemons. Application of these results to quarantine risk analysis is discussed.