Phone calls on rice water weevil adults moving into rice have picked up tremendously over the past two weeks. A few weeks ago, we made the comment that it was too early to predict what kind of weevil year we would have this year and based on what we have seen the past few days it’s going to be bad.
So, the thing to keep in mind about weevil control is application timing. Typically, an application would be made within 5-7 days after permanent flood establishment. For a lot of the rice that is just now going to flood, we expect to see weevils show up immediately.
We are still seeing some cases where rice has been flooded for a couple of weeks and adults are just now moving into the field. In these cases, we are still suggesting you spray if there is a large amount of scarring and adults. When scouting for weevils, we are looking for 40-50% scarring on new leaves and adults present before we make a foliar application.
Some of the questions we have gotten around weevil control here lately have been should I still spray if I have Fortenza or Dermacor seed treatments. The answer is no, these products don’t have adult activity so you will still see the scarring occur, but they are great for larval control which is the damaging stage.
CruiserMaxx and NipsIt will provide some adult control, but for a lot of the rice that is just going to flood is ranging from 40-60 days after planting. CruiserMaxx and NipsIt are only going to last 28-35 days, and we need to be prepared to have to treat these fields with a foliar for weevils.
We have also gotten questions about replanting rice and whether or not it needs a seed treatment. The bottom line is we suggest all acres of rice in Arkansas receive a seed treatment regardless of planting date. This late in the growing season, rice is going to come out of the ground growing rapidly.
It’s going to be possible to use a CruiserMaxx or NipsIt and be able to get to flood within that 28-35 day window. Keep in mind that, like with most insect pests, the later we plant the higher the rice water weevil populations will be.
Rice water weevil is the number one insect pest of rice in the midsouth. As we flood more rice over the coming days, we need to be scouting these fields within 3-4 days after permanent flood establishment so we can make decision on rice water weevil. Feel free to contact us if there are any questions.