Forest Tent Caterpillar

Sometimes mistakenly called army worms, Forest Tent Caterpillar have become a nusiance to land owners throughout Minnesota.


Read the University Of Minnesota Extension Service Bulletin

West Central Ag-Air can apply a microbial pesticide for control of these pests.

The pesticide contains the spores and endotoxin of a soil born bacteria called Bacillus Thuringiensis. (Commonly abbreviated as Bt.) Bt only has effect on caterpillar species and has been in use for decades for caterpillar control throughout the United States and Canada. The commercial name of the product that we use is called Foray 48B.

Foray 48B Information

Foray 48B Label

Foray 48B MSDS

Spray Status Click Here:  FTCcustomer status 6.1.20

File last updated:6/11/19

Call or email Ryan today for more information on how to get your area sprayed.

Office: 218-736-7220  Cell:  218-770-0130  Email:

The best size for the most effective application.



One spray area representative must call or email me as soon as the caterpillars are 1/2 inch long.


Actual spray date/time will depend on pest stage and weather.


We do not spray caterpillars on the weekends or holidays.


Weather effects on Foray applications. (pdf)

NPDES permit information

Compliance with the Minnesota Pollution Control Agency’s National Pollutant Discharge Elimination System is now required.  You can view the permit here:

Forest Canopy Insect Pest Control Pesticide General Permit

MPCA’s NPDES permit site.

Appilcations less than 6400 acres will be covered under the general permit.  The customer is considered the “decision-maker” and must comply with the terms of the general permit. The following is an easy to follow checklist for compliance. Customers must print and follow the checklist in order to ensure permit compliance.

NPDES Checklist