Abstract

The boll weevil is considered the major pest of cotton in the Western Hemisphere due to the large potential for direct destruction of fruiting bodies, survival on the fallow ground and dispersal ability. The purpose of this study was to evaluate the feeding preference of Anthonomus grandis for squares at different ages, as well as the abscission of attacked squares on five cotton cultivars. The experiment was conducted in Jaboticabal, SP, Brazil, in 2010 and 2011. Newly formed squares of the cultivars NuOPAL, DeltaOPAL, FMT-701, FMX-910 and FMX-993 were chosen and labeled for daily observations. Each evaluation was based on the registration of the age (days) at which the squares were fed to A. grandis and the time (days) from the first hole of boll weevil feeding until boll abscission. Results indicated a greater preference of the boll weevil for squares of the cultivars FMT-701, FMX-910 and FMX-993 than of the cultivars NuOPAL and DeltaOPAL. A. grandis prefers smaller two-day-old squares of the cultivars NuOPAL and FMX-910 and larger, seven-day-old bolls of the cultivars DeltaOPAL, FMT-701 and FMX-993. All feeding punctured squares fell on the ground, and the time of square abscission was independent on the age and cultivar of the square and was 1 to 2 days after the first feeding puncture.

Key words: Anthonomus grandis, host plant, injury, Gossypium hirsutum.