Buzz
Pine caterpillars are a type of moth larvae that feed on a variety of plants, including shrubs, trees, and fruit-bearing plants. They especially thrive on fallen leaves, conifers, and perennials. However, they only cause harm to non-shedding conifer trees. The main methods to eliminate them involve using hands and pesticides during specific stages of their development.
Steps
Monitor pine caterpillars
Start searching for pine caterpillars when the weather turns cold, usually in late fall or early spring. The caterpillar's eggs are brown and measure around 0.5 to 2 inches (3.8 to 5 cm) in length. They are often covered with dry pine needles, making them easy to spot due to their contrasting color compared to the surrounding fallen green needles at this time of year.
- The eggs can be difficult to spot as they resemble pine cones. Carefully inspect the cones to identify subtle differences.
Regularly sweep and rake the area beneath the tree to remove any scattered egg sacs. Avoid piling up trash as larvae may take refuge in it. Place waste in a sealed plastic bag inside the trash bin.
Pay attention to areas with dry pine needles or branches. If the tree begins to turn brown, it's likely that the caterpillars have harmed it. You will need to take drastic measures to prevent them from damaging the entire garden and spreading to other plants.
Keep an eye on new spots where caterpillars might hide. Wind can carry silk threads all around. Any area in the yard where the wind blows could be a new hiding place for them, making it something worth monitoring.
Eliminate caterpillar eggs
Pour a mixture of warm water and dish soap into a plastic bucket. Stir the solution well to combine the ingredients.
Wear gardening gloves and carry a small pruning shears to help with the complete removal of caterpillars. The shears will help clear away the silk trails left by the caterpillars, making it harder for new ones to find a way to infiltrate the tree.
Lift the branches, cut the caterpillar egg sacs, and place them into a bucket filled with soapy water. Ensure that all the sacs are fully submerged.
Place the soapy-water-soaked caterpillar egg sacs into a sealed plastic bag and throw them into the trash.
Repeat this process every fall, winter, and early spring to reduce the number of caterpillars before the eggs hatch. By carefully collecting the egg sacs, you will minimize the amount of pesticides needed.
Eliminate hatched caterpillars
Plan to treat caterpillars with pesticides in May. This is when the eggs hatch, and they are most vulnerable. In some areas, the eggs may hatch as late as early June.
Look for a small head, resembling a caterpillar emerging from the top of the egg sac. However, they tend to retract into the sac if startled.
Purchase pesticides such as Dipel or Thuricide. These contain Bacillus thuringiensis, a bacterium that kills caterpillar larvae. If you have many trees threatened by caterpillars, the cost of completely eliminating them with pesticides can be quite expensive.
- Orthene, Talstar, and Tempo are other pesticide options that are effective in killing newly hatched caterpillars.
Fill a spray bottle with the pesticide. Thoroughly wet all the leaves and pine needles that are at risk of being attacked by the caterpillars. Be cautious when spraying around areas with pets and children.
- Consider isolating the area immediately after spraying.
Spray the pesticide at the end of May, throughout June, and early July. This is when you can effectively eliminate newly hatched larvae. Stop spraying by the end of July and early August, as the caterpillars will be recovering, and the pesticide will no longer be effective.
- By September and early October, the adult caterpillars will begin fertilizing the eggs. At this point, you should begin manually collecting the egg sacs.
- The male adult caterpillars usually have black wings with brown spots. They will die after mating. The female caterpillars remain dormant in the egg sacs during their larval stage.
The items you will need
- Plastic bucket
- Water
- Dish soap
- Gardening gloves
- Pruning shears
- Pesticide
- Plastic bags
- Rake
