Author
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CASTLE, STEVE - PREVIOUS WCRL, BRAWLEY,CA |
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Henneberry, Thomas |
Submitted to: Silverleaf Whitefly: 1997 Supplement to the Five Year National Research and
Publication Type: Abstract Only Publication Acceptance Date: 8/1/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: To determine the pattem for B. tabaci, progeny sex ratios from single pair matings were studied in a greenhouse using field collected parents. Single males and females were randomly paired within an 8 cm sq clip cage attached to whitefly-free cantaloupe plants. A cohort of 36 pairs were followed over a 24 day period. Serial tranfers of the parental pairs were carried out on 6x different leaves/pair. The duration on each leaf from first to last interval was 3, 3, 3, 4, 4, and 7 d, respectively. Once attached, clip cages remained in position on leaves through courtship and copulation, egg laying and hatching, immature development and emergence of the next adult generation. The mean number of male and female progeny/female/day was determined for the 11 pair in group A that remained intact for entire 24 d period. Beginning day 5-20 of 30 d emergence period, numbers of female progeny consistently exceeded male progeny, on some days by ratios of 2:1 or greater. Only at beginning and end of emergence period were male and female proportions near parity. Mean number of total progeny per female per day exceeded 20 on 15 of the 30 day emergence period. Based on these daily per capita progeny production data, estimates of r, the intrinsic rate of increase, were obtained. Two different methods to estimate r were used, each one giving almost identical r values. Average r calculated from data for 11 pair in group A was 0.228, with a range of 0.220 to 0.237 for individual females. |