Alfalfa Weevil and Black Cutworm

Alfalfa Weevil

Reports from Michigan and Iowa indicate that alfalfa weevils were activity is early this year.  We’ve had some fairly warm weather earlier this spring and the weevils likely have had a bit of a head start. I was out in some fields in Oxford this week and I found some early instar larvae so the weevils are out there. Start your scouting program early this year. Check out the Agronomy Guide for Field Crops publication 812 for scouting tips and control thresholds.

Black Cutworm

Black cutworms were being caught in high numbers in Indiana over the last few weeks and Pennsylvania has reported minor activity with catches increasing in some areas.  These moths no not over winter in Ontariobut are brought in on strong storm systems that come up from the South. Black cutworm females will lay their eggs in low-growing green vegetation (particularly chick weed) and fields with weed growth are tempting places for these moths to land and lay eggs. Later planted corn is at a higher risk of damage from the cutworms since the insects are much larger when the corn seedlings emerge. Bt hybrids that contain Vip3A (Agrisure Viptera 3110 / 3111) provide good control and hybrids that contain Cry1F (Genutiy, SmartStax, Herculex I, Herculex XTRA, SmartStax and Optimum products) may only provide some suppression of younger larvae. Rescue treatments can be effective if infestations are found in time.

Considering that the migratory insects such as the red admiral butterfly are about 2 weeks early this year, storm fronts from the south are likely to bring up BCW a bit earlier. Expect to be scouting once the corn is up.  For more information on black cutworm visit the following link:

Other things to look for:

Cereal leaf beetle adults have been found in the Alliston area though the numbers are not at thresholds.