By — Dr. Jeff Whitworth, Dr. Holly Schwarting
Most corn has been planted in SC and NC Kansas, although some has been struggling somewhat with the cooler temperatures, wet soils, etc. Whatever the case, please remember insecticide seed treatments do a good job of protecting the seed and germinating plants, but not forever. About 3-4 weeks of protection from the time of planting can be expected but after that, wireworms, white grubs, etc. may affect the seedlings, especially under less than ideal growing conditions.
–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Alfalfa weevils are still very active throughout north central Kansas. They also range in development from small 1st instar larvae to relatively mature 3rd instars.
We have also had reports of pupae in south central and north central Kansas. Many fields are still showing signs of freeze damage.
The freeze did seem to affect the weevils by slowing their development but did not kill them. However, most larvae in freeze-damaged fields are more yellow than the usual greenish color. Whether that means they are getting the proper nourishment from the yellowed, freeze-damaged alfalfa tissue or not is unknown.
Weevil larvae in untreated, non-freeze-damaged fields seem mostly about to pupate within 7-10 days if temperatures stay between 45-80°F. No other pests have been noted in alfalfa fields we visited over the past week.
—by Dr. Jeff Whitworth and Dr. Holly Schwarting
Aphids, mainly bird cherry oat and greenbugs continue to migrate into wheat fields throughout north central and south central KS (see photos). When temperatures are warmer and winds are from the south, these aphids are migrating/blowing in, in significant numbers. However, we did note some mummies (parasitized aphids) in these fields so these little wasps are active and will probably help control these pests if insecticides are not used in these fields.