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Sampling Efficiency of the Keep-it-Simple-Sampler
for Adult Boll Weevils |
ABSTRACT Early-season boll weevil (Anthonomus grandis Boheman) populations are difficult to sample because their levels are typically low and labor requirements for precise estimates are prohibitive. Recent studies suggest a hand-held pneumatic sampler (Keep-It-Simple-Sampler; KISS) may offer a less laborious alternative to hand-sampling, but detailed estimates of KISS collection efficiency in different phenological stages of cotton (Gossypium hirsutum L.) are not available. We used mark-and-release techniques to obtain preliminary estimates of KISS collection efficiency for boll weevils in pre-fruiting, pinhead square, and third-grown square stages of cotton. Observations of weevils released in pre-fruiting cotton indicated a majority of weevils (97%) remained on the cotton plants between the time of release and sampling with the KISS. Overall, recovery of weevils by the KISS 20 min after release was about 11%. Further, about 13% of marked weevils were dislodged from the plant but not collected by the KISS. In comparisons of collection efficiency among plant phenologies, the mean percentages of marked weevils recovered from pre-fruiting (19%), pinhead (21%), and third-grown square (12%) stage plants were not statistically different. The KISS detected weevils in most samples and the overall estimated collection efficiency was 17±12%. The low and variable recovery rates we observed suggest the KISS does not provide precise estimates of low-level boll weevil populations. Despite this shortcoming, the KISS remains a labor-efficient tool for detecting low-level populations, especially in the absence of practical alternatives. |
©National Cotton Council, Memphis TN |
Document last modified April 16, 2003
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