We are unsure what you are treating for but we have linked the product label instructions below:
http://www.domyownpestcontrol.com/msds/MontereyBt-2-column-0911%2801%29_%281%29.pdf
Monterey B.t. Insecticide? is an organic OMRI rated insecticide and should not be mixed with any other insecticides. Doing so would change its formula and composition and it would not longer work as intended. Monterey B.t. Insecticide is mixed at 1.5 oz. per 3 gallons of water per 1,000 sq. ft. for Fruits and Vegetables and 2 oz. per 3 gallons of water per 1,000 sq. ft. for Ornamentals.
Sevin Insecticide Granules are not labeled for Gypsy Moth Caterpillars. Monterey B.T. Insecticide is labeled for gypsy moth caterpillars and can be used on fruits, vegetables, ornamentals and shrubs.
Fruits and Vegetables: 1.5 oz. per 3 gallons of water per 1,000 sq. ft.
Ornamentals 2 oz. per 3 gallons of water per 1,000 sq. ft.
Monterey B.t. Insecticide is not labeled for use on home lawns. Bifen IT would be a better option.
Monterey B.t. Insecticide can be applied in a hand pump sprayer or hose end applicator for applications to shade trees and ornamentals.
Monterey B.t. Insecticide will last about 3 years once opened as long as stored correctly. Keeping it out of extreme temperatures & out direct sunlight. If the bottle was already open, we would not advise using a 5 year old bottle
Monterey B.t. Insecticide should be applied with a handpump sprayer. It is not labeled to be used in a cold fogger.
Monterey B.t. Insecticide is not labeled to treat for spiders.
Monterey B.t. Insecticide is not labeled for fleas or ticks. Wondercide Outdoor Pest Control - Lawn and Landscape would be a good natural product to use.
Monterey B.t. Insecticide is not labeled to control fungus gnats. Ultra-Pure Oil Horticultural Insecticide, Miticide and Fungicide. Please refer to the product label for application rates depending on where you are treating.
Monterey B.t. Insecticide should only be mixed with water and we would not recommend tank mixing with other products.
The mix rates for Monterey B.t. Insecticide range from 1.5 fl oz to 2 fl oz per 3 gallons of water per 1000 sq ft depending on if you are treating Fruits and Vegetables (1.5 oz per 3 gallons of water/1000 sq ft) or Ornamentals (2 oz per 3 gallons of water/1000 sq ft)
Please be sure to review the product label for more information and complete application instructions.
Monterey B.t. Insecticide can be applied in a hand pump sprayer or hose end applicator for applications to shade trees and ornamentals. Please refer to the product label for complete instructions on your target application.
Once the application of Monterey B.t. has had time to completely dry, then it is okay for water to get on the plant.
Monterey B.t. Insecticide is not labeled for this use. We would recommend reaching out directly to the manufacturer to see if there is new information on this product.