• Control of Sweepotato (Silverleaf) Whitefly, Bemisia Tabaci, on Cotton in Paloma, Arizona

      El-Lissy, O.; Antilla, L.; Staten, R. T.; Leggett, J. E.; Walters, M.; Silvertooth, Jeff; Arizona Cotton Research and Protection Council, Phoenix, AZ; USDA-Animal and Plant Health Inspection Service, Phoenix, AZ; USDA-ARS-Western Cotton Research Laboratory, Phoenix, AZ (College of Agriculture, University of Arizona (Tucson, AZ), 1994-03)
      A large scale for the control of sweetpotato (silverleaf) whitefly, Bemisia tabaci, (SPW) was carried out in Paloma and Painted Rock near Gila Bend, Arizona, on approximately 6,156 ha of cotton during the 1993 season. Within the program area 40 fields were randomly selected for comparison with 15 fields in each of 2 locations outside the program. They were identified as check east (approximately 11 k northeast of the program) and check west (approximately 3 k west of the program). Whitefly populations in both check areas were controlled according to individual grower protocol. On a weekly basis, adult counts were taken from all 4 edges and the centers of each field using the oil pan technique. Insecticides were applied aerially in the program area on the full field or edges based on population density recorded from pan samples. Insecticide combinations were rotated weekly in an attempt to reduce the potential for the development of pesticide resistance. During the 16 -week evaluation period SPW adults were significantly higher in check east and check west than the program area by 2- and 6-fold respectively; eggs were higher by 3- and 39 fold, respectively; and nymphs were also significantly higher in check east and check west by 3- and 60-fold respectively. Ginning records for 1993 indicate approximately a 20% increase in yield in the program area a 5% increase in check east and a 40% decrease in check west as compared to 1992. These results demonstrate that an area -wide approach, utilizing edge treatment where possible, based on extensive field sampling regimens represent an important integrated strategy in a successful whitefly control program.
    • Influence of Pink Bollworm, Pectinophora Gossypiella, (Saunders) (Lepidoptera : Gelechiidae), Female Age on Oviposition Capacity and Egg Hatchability

      El-Lissy, O.; Al-Beltagy, A.; Antilla, L.; Leggett, J. E.; Silvertooth, Jeff; Arizona Cotton Research and Protection Council, Tempe, AZ; Plant Protection Research Institute, Cairo, Egypt; USDA -ARS- Western Cotton Research Laboratory, Phoenix, AZ (College of Agriculture, University of Arizona (Tucson, AZ), 1994-03)
      Oviposition capability and e 4: hatchability of three laboratory reared strains of pink bollworm, Pectinophora gossvpiella, (Saunders) were evaluated to determine the effect of age on the female reproductive capacity. From comparisons of various female ages in terms of the amount of eggs deposited and the level of ex hatchability, it was concluded that young females (3-6 days old) had the highest potential for oviposition and that their eggs had the highest percentages of hatchability.