Armyworm continues to be a significant problem in Butte County with 60,000 acres treated for the pest. In many cases, multiple applications have been required to provide some level of control. We also understand that the pest is appearing in Glenn County and Colusa County. There are a few reports of the pest south of Butte County.
The conventional crop protection materials do not seem effective, since the worms are visible in the larger stages. The result has been repeat applications and shifting to different materials.
On a positive note, the pressure seems to be abating with the downward trend in the number of NOI’s filed.
Since our first communication, we have researched several crop protection materials, as options for either an emergency exemption or special local need registration. Unfortunately, the California rice industry does not commonly experience outbreaks of insect pests – in this case Lepidoptera pest. As a result, few new options are available.
The Department of Pesticide Regulation is well aware of our situation and working with us to find an immediate resolution. We will continue to pursue a longer-term, permanent solution after this season so that the tools are available to control unexpected future pest outbreaks.
Key Information from UC Cooperative Extension
Photo Credit: UC Cooperative Extension