Hello,

Sorry to hear about your evergreens! Colorado is tough on plants (and animals)!

Natural & Organic Controls

What?

The combination of Insecticidal Soap and Botanical Pyrethrins will kill Sawfly Larvae on contact if they are spotted in your trees. Azadirachtin is also an effective control for Sawfly Larvae.

How?

Insecticidal Soap (Potassium Salts of Fatty Acids) & Pyrethrin - The soap will penetrate the insect's shell and kill it by dehydration. Adding Pyrethrin creates the organic equivalent of a 1-2 knock down punch. Pyrethrin is a nerve agent that will absorb into the insect and kill by paralysis.

Keep in mind, this soap is not like dish detergent, it's a base from a blend of natural plant sources and pyrethrin oils and come from the chrysanthemum flower. An effective and organic combination...

Azadirachtin - A derivative of the Neem Tree, Azadirachtin is an insect growth regulator (IGR). It disrupts and speeds up the molting process of larval insects. It kills the insects when they try to molt to the next phase of life too soon. This natural control also repels the adult sawfly and many other insects.

Safer® Brand offers a variety of sawfly larvae control products to help control and eliminate this garden pest and revive your plants. Please check out our sawfly larvae control products for more details about how they work and how, when, where they should be applied.

Carefully read and follow all instructions on the product packaging for safe and effective results. It is recommended with any pesticide to test plants for sensitivity to the product. Spray a small section of the plant in an inconspicuous area and wait 24 hours before full coverage.

When?

Since these formulas are contact killers and they do not persist in the environment, several applications may be needed for full control. As a general rule, much like watering, do not use these products in the peak of the day or when temperatures exceed 90 degrees F to avoid wilting or browning of the leaves.

Why Choose a Natural Solution?

These organic solutions break down into their natural elements within 7-10 days leaving no residual impact on the environment.

They are highly preferable to chemical pesticides with toxins that can cause long-term detrimental effects on the environment. Another negative effect of the chemical pesticides is the sawfly's possible buildup of resistance to the chemicals in the pesticides.

Natural Predators

What?

Natural enemies of the conifer sawfly include parasitic insects, especially parasitic wasps. These insects are great partners in helping to control sawfly infestations in your organic garden.

How?

Parasitic insects, including parasitic wasps, lay their eggs inside the sawfly's body eventually killing the host insect. Lure parasitic insects to your garden by planting nectar or pollen producing plants.

To aid the organic gardener, parasitic wasps and other parasitic insects can be purchased through a commercial insect breeder. Make sure if you purchase these insects you have an actual garden insect infestation or you may notice parasitic wasps migrating to your neighbor's yard in search of food.

When?

In the spring, parasitic insects may lay their eggs in the larvae of the conifer sawfly.

Plant nectar or pollen producing plants according to your local greenhouse or garden center's suggestion.

Environmental Controls

What?

Collecting and destroying larvae and knocking them off trees will help control these pests. These methods should be used in combination with other control methods such as natural and organic controls.

How?

Lay sheets on the ground around the pine trees to catch larvae that fall, then gather and destroy the larvae. Remove larvae by hand picking when the infestations are small.

When?

When larvae are spotted, these environmental control measures should be taken. Delaying the use of control measures may allow populations to rise and damage to increase.

It may be a little “late in the season,” but this year things seem to be developing slower. Below are a couple of links that are research-based from CSU, and what works best is probably a combination of natural and chemical solutions, but you could try the natural way first (insecticidal soaps/knocking off with water spray, etc.).   Most of these “cures” work with the help of chemicals. Here are a few links that you should read and review:

http://www.ext.colostate.edu/ptlk//1439.html

http://www.extension.umn.edu/garden/insects/find/sawflies/

Best of luck,

Susan H.

DC Master Gardener