Monitor the Alfalfa trunk beetle with final days, scouting

Alfalfa trench beetle will be laid in ALFALFA stems in autumn and spring. The larvae feed at the beginning of the spring of terminals and upper plant leaves, which leads to damage before cutting.

Alfalfa trunk beetle studies are a great way to estimate what is going on on site and know as a useful tool when they are scouting. Alfalfa trunk beetle begin after 300 degrees have accumulated.

Since we cannot determine whether the eggs present were set in Kansas in the previous autumn or in the current spring, the scouting should begin from 1st January after 180 degrees.

How do I know how many grades have accumulated days?

For the latest ALFALFA trench beetle accumulations for the coach beetle you will find the Kansas Mesonet Grad Days Calculator and find the Mesonet weather station closest to you. Click on it, then on Alfalfa Rheevil and click Send. This shows you the accumulation of Alfalfa trench beetle.

At the time of this letter, the Hays Mesonet has a accumulation of 167 -degree days.

A complete guide to recommendations for the management of Alfalfa Wheevil can be found in the upcoming publication of K-State Research & Extension 2025 Alfalfa Insect Pest Management Management, which will be available online shortly. Google it just and you should find it.

Observe insectic resistance.

While warmer springs temperatures enable faster development of Alfalfa trunk beetles, you should aware that dramatic temperature waste can slow down the Alfalfa growth, which means that the plants are unable to keep up with nutritional damage.

Treatment can be between 3 and 7 inches in the shorter fields if the feeding on the upper customs of growth is visible and there are 1 to 2 larvae. If a field is treated, it is important to check whether the expected control has been achieved.

In 2020, the populations of Alfalfa Rüsselkäfer against Lambda-Cyhalothrin (Warrior II with Zeon Tech) were checked northwest and southwest Kansas and Oklahoma.

Although this resistance for Kansas producers did not seem to be a widespread problem, be aware of it and after use the fields continue to be on the scout fields. Oklahoma continues to resistance nationwide.

Numerous products are available for control of the Alfalfa trunk beetles in Kansas. When deciding on management decisions, it is important to turn the modes of action, i.e. pyrethroid and organophosphate. This is a way to slow down the development of resistance.

A comprehensive list and description of all currently recognized promotional modes can be found at https://irac-online.org.

In 2024, an update for the awareness of the options was to ban the decision of the EPA, Chlorpyrifos (Lorsban and others). The EPA then published a technical correction in which 11 special uses of chlorine pyriphos were permitted. The 11 special uses relevant to Kansas include Alfalfa, cotton, soybeans and winter wheat.

If you have any questions, contact your local agricultural or district extension office.

Information from Anthony Zukoff, K-State expansion tomologist.

Stacy Campbell is an agent for expanding plant production in the Cottonwood district (which also includes the counties Barton and Ellis) for K-State research and extension. You can contact him by email [email protected] or by phone at 785-628-9430.