Efficacy of Insecticides to Citrus Thrips on Lemons in Yuma Arizona 1997

Abstract

Three small plot efficacy trials were conducted evaluating different insecticide rotation regimes using commercially available insecticides and the effectiveness of new insecticide chemistries to control citrus thrips. Because of its long residual activity, and ability to control post- application egg hatches, Carzol appears to be the product that best fits the petal fall application window. Agri-Mek, Baythroid, Dimethoate or Vydate are probably good follow -up insecticides. However, Agri-Mek and Baythroid will probably provide greater control, especially under hotter conditions. If temperatures are cool, Agri-Mek looks good at reduced rates. The best insecticide for subsequent applications depends on temperatures and what was previously applied. Avoid making back -to -back applications of the same materials, and Dimethoate or Vydate applications should probably be followed by Carzol to catch post- application egg hatches. Overall, Vydate appears to be very similar to Dimethoate in efficacy and residual activity, while Baythroid appears to be slightly better. Although the addition of Lannate to Dimethoate does slightly enhance thrips control, the additional cost probably does not justify the tank mix. Of the new chemistries (Alert, Success, Ni-25, and M-96-015) evaluated, Success and M-96-015 appeared to offer the best fruit protection. However, M-96-015 does not appear to be very effective in killing the thrips, but is very effective in repelling them. Also, M-96-015 will need to be applied at a high gallonage, i.e. 500 gal/A. None of the new products tested appear to fit the petal fall application window very well. Ni-25, Alert and Success appear to lack the residual activity of Carzol, and M-96-015 should not be used as a clean-up material but preventively following Carzol at petal fall.