Caterpillars are a huge problem in Canada. They can defoliate trees and destroy your garden in a matter of days. Even though you may not see the caterpillars themselves, evidence can be found in the form of droppings and foliar damage.
Cabbage worms are green and like to hide on the underside of leaves. They especially like to prey on leafy greens like lettuce, kale and cabbage, and have been known to destroy young cauliflower plants before they have a chance to flower. It is important that you identify a cabbage worm infestation immediately.
There are two main varieties of tent caterpillar currently found in Alberta:
Forest tent caterpillars, the blue variety of tent caterpillar, defoliated 4.8 million hectares of Canadian forest in 2015.
If you find an actual tent in a tree, that tent is most likely to belong to the Eastern tent caterpillar, which are black and orange. These caterpillars cause less damage than the forest tent caterpillar, but are unsightly.
LDD Moth Caterpillars (Lymantria dispar dispar, "European Gypsy Moth") are often confused with tent caterpillars. They are considered an invasive species and a very serious pest and steps should be taken to eliminate them as soon as they're spotted.
Safer's BTK Caterpillar Killer is a biological insecticide that controls caterpillars including cabbage worm, tomato hornworm, tent caterpillars, LDD moth, leafrollers, and other listed insects. Simply mix the concentrate with water and spray on vegetables, fruit, trees, and ornamentals. After ingesting the treated portion of the leaf, caterpillars stop feeding within hours and die within a few days. This 100mL concentrate makes 33.3L of solution.
- Controls caterpillars including cabbage worm, tomato hornworm, tent caterpillars, LDD moth, leafrollers, and other listed insects
- Can be used on vegetables, fruit, trees, and ornamentals
- Active Ingredient: Bacillus thuringiensis subsp. kurstaki, strain ABTS-51
- Makes 33.3L
BTK is generally regarded as environmentally safe, as its toxicity is essentially limited to its target pest; humans, wildlife, and beneficial insects are regarded as unaffected by the pesticide. This means that you'll only be killing pesky caterpillars, not your bee friends!
Identification: These bright green or turquoise inchworm-like caterpillars are typically found on the undersides of your leaves. They are well camouflaged. Leaves may appear weighted-down.
Control: Pyrethrins, insecticidal soap, yellow sticky traps, diatomaceous earth, hand-picking.
Biological Control: BTK
Notes: Caterpillars are typically only a problem on outdoor grows. They must be dealt with swiftly, as they can devour your entire crop in a matter of days. Plants such as lettuce, Swiss chard, cabbage and cauliflower are magnets for cabbage loopers. Kill any moths that enter your grow room.
LDD Moth Caterpillars
Control: Pyrethrins, insecticidal soap, burlap, sticky traps, duct tape wrapped "sticky side" out around the base of your trees, folded burlap cloth wrapped around trees, hand-picking, water jets, stomp on the little sh**s.
Biological Control: BTK
Notes: The LDD Moth is an invasive species that puts Canadian forests at risk. These caterpillars can defoliate your decorative trees extremely quickly, and thus must be dealt with immediately. They are covered in small hairs that can cause rashes in susceptible people. We recommend you use gloves when handling them.
To treat a caterpillar exposure:
- If the caterpillar is on the skin, remove it without using your hands!
- Gently put tape over the exposed area, sticky side down. (Any kind of tape will do.)
- Pull up the tape, removing the hairs or spines.
- Repeat with fresh pieces of tape as often as needed to treat the area involved.
- Wash the area gently with soap and water.
- If the area itches, put on a paste of baking soda and water.
- If that doesn't help, try a hydrocortisone cream.
- If that doesn't help, try an antihistamine cream. That shouldn’t be the first choice, as it doesn't always help. Also, some people have skin reactions to these creams.
- If the area is badly blistered, contact your health provider.
- Call your health provider about a tetanus booster if your shots are not up to date.