Chemistry Reference
In-Depth Information
Overall, the effectiveness of dinotefuran against CPB and PLH was influenced by the
amount of rainfall significantly more than either imidacloprid or thiamethoxam. Under a
high rainfall regimen, plots that received a treatment of dinotefuran were not significantly
different from plots that received no insecticide for either CPB mortality or for CPB leaf
consumption, and under a low rainfall regimen the effectiveness of dinotefuran against CPB
was significantly shorter over time than either imidacloprid or thiamethoxam. It has to be
mentioned that our findings reflect the worst-case scenarios for rainfall (maximum rainfall
total of 60.96 cm [24”] laboratory and 50.8 cm [20”] field) and that under practical conditions
lower amounts of rainfall would likely naturally occur. These high rainfall amounts likely
caused exaggerated leaching of all of the neonicotinoids, especially the highly soluble
dinotefuran, resulting in reduced control of the CPB and PLH.
Results of the present study show that rainfall has an impact on effectiveness of soil-applied
imidacloprid, dinotefuran and thiamethoxam for both CPB and PLH control in white
potatoes. However, growers should not rotate imidacloprid or dinotefuran with
thiamethoxam as part of their resistance management program. Alyokhin et al. (31) showed
that the correlation for LC
50
values for imidacloprid and thiamethoxam was highly
significant using diet incorporation bioassays, and that there was substantial cross-
resistance among three neonicotinoid insecticides. Further, Mota-Sanchez et al. (32) reported
that cross-resistance was observed with all 10 different neonicotinoids in a bioassay using
topical applications. They concluded that the rotation of imidacloprid with other
neonicotinoids may not be an effective long-term resistance management strategy. For
effective insecticide resistance management, control of CPB should not depend exclusively
on the neonicotinoid class of insecticides. It is important to use all available effective pest
management tools, including crop rotation, border treatments, and non-neonicotinoid
(different class) insecticides.
Author details
Gerald M. Ghidiu
Rutgers- the State University, Department of Entomology, New Brunswick, NJ, USA
Erin M. Hitchner
Syngenta Crop Protection, Elmer, NJ, USA
Melvin R. Henninger
Rutgers- the State University, Department of Plant Biology and Pathology, New Brunswick, NJ,
USA
5. References
[1]
Capinera, J.L. 2001a. Handbook of Vegetable Pests. Academic Press, New York, NY. pg.
96-98.
