–by Dr. Jeff Whitworth
Alfalfa weevils have been, and are still, very active throughout south central and north central Kansas during the last few days, even through the cold weather. However, just as the alfalfa plants have been variously affected by the recent cold weather, so have the alfalfa weevil larvae. The plants shown towards the middle of this picture (Fig. 1),
Figure 1Alfalfa freeze damage (picture by Cayden Wyckoff)
had the upper part of the foliage killed by the recent cold temperatures, as were the larvae in that foliage (Fig. 2).
Figure 2 Dead and live AW larvae (KSU Extension Entomology)
The adjacent plants were not as seriously affected and thus, neither were the larvae in those plants.
Thus, each field needs to be monitored at least weekly, even those fields already treated. Nevertheless, please — always remember, to follow all label directions for whatever product applied, especially as far as reentry, PHI, etc.