Modelling the effect of pyrethroid use intensity on mite population density for walnuts

作者：Zhan Yu; Fan Siqi; Zhang Minghua^*; Zalom Frank

来源：Pest Management Science, 2015, 71(1): 159-164.

DOI：10.1002/ps.3799

• pyrethroid
• miticide
• mite
• walnut
• integrated pest management

BACKGROUND: Published studies relating pyrethroid use and subsequent mite outbreaks have largely been based on laboratory and field experiments, with some inferring a result of increased miticide use. The present study derived a mathematical model proposed to quantify the effect of pyrethroid use intensity on mite population density. The model was validated against and parameterized with actual field-level pyrethroid and miticide use data from 1995 to 2009 for California walnuts, where the miticide use intensity was a proxy of the mite population density.
RESULTS: The parameterized model was MI = 1.61-0.89.exp(-93.31PI) (RMSE = 0.13; R-2 = 0.69; P < 0.01), where PI and MI are the average pyrethroid and miticide use intensity in small intervals respectively. A three-range scheme was presented to quantify pesticide applications based on the change rate of MI to PI. Specific for California walnuts, the PI range of 0-0.025 kg ha(-1) was identified as the rapidly increasing range where MI increased vastly when PI increased.
CONCLUSION: Results confirmed that more miticide was used, presumably to prevent or control mite resurgence when pyrethroids were applied, a practice that is not only costly but might be expected to aggravate mite resistance to miticides and increase risk associated with these chemicals to the environment and human health.

• 出版日期2015-1