Sawflies are probably the most confusing lot of the insect world. They do not have any particular specific look because they keep changing as they grow. Sawfly larvae look like little slugs then they slowly start looking like caterpillars and then eventually end up looking like a cross between a fly and a wasp. Considering the fact that an adult sawfly looks like a wasp, does a sawfly sting?
Strangely enough, no, Sawflies do not sting. In fact, they are often referred to as stingless wasps. These little insects get the common ‘wasp’ name from the way they look. Females have an ovipositor that unfolds like a jackknife. This functions like a saw blade which allows the female to cut through host plant stems to deposit her egg.. Although this feature does look a lot like a stinger, it really poses no harm to humans or their pets.
You might be wondering, if sawflies do not sting and are not a danger to humans or their pets, then why are we concerned about them? The truth is that, although these little critters are not exactly harmful to humans nor their pets, sawfly damage can be severe in terms of host plants. Typically, gardeners or farmers will encounter sawflies in the larvae form. This is when they are at their most destructive to plants.
Sawfly larvae have a habit of feeding on plant leaves thus destroying a good portion of your crop if not mitigated. The problem is that since their larvae look a lot like caterpillar larvae, most farmers, upon encountering these little buggers, assume they are dealing with a caterpillar problem.
This leads to quite a bit of confusion as the farmers try to use the typical, ‘get rid of caterpillar larvae’ methods, most, if not all of which, will NOT work on sawflies. The easiest way to differentiate between the two is to disturb a few of these larvae when they are feeding. If they rear up their hind ends, then you have a sawfly problem.
The Life Cycle of A Sawfly
This video gives you a good idea of the lifecycle of a sawfly and how they feed on your plants:
There are many different species of sawflies. Some of these species only ever have one generation per season while others might have several generations within the same season. Adult sawflies go about laying hundreds of eggs on or in plant leaves. After a short while, the eggs hatch into sawfly larvae in late spring or early summer. These larvae then begin ferociously feeding on the host plant leaves.
These little pests tend to feed on the same species of plant. In fact, if you want to know what kind of plant any particular species of sawfly feeds on, you only need to look at its name. Here are a few good examples:
- Oak Sawfly feed on oak trees
- Raspberry Sawfly feed on raspberries
- Pine Sawfly feed on pinewood
It goes on like that for several other species of sawflies that specialize in feeding on specific plants. That is why they are often referred to as ‘specialist pests’.
The Willow Sawfly, for example, is really good at defoliating willows. There are about nine different sawfly families with some members being more peculiar than others. The strangest sawflies have to be those belonging to the family Pamphiliidae. These use silk-producing glands to fold plant leaves into well-camouflaged shelters.
How to Control Sawfly Larvae
There are several methods you can use to control sawfly larvae, but first, you need to identify the sawfly before you go about eradicating it. The easiest way to do this is to disturb the leaves that the larvae are on and see if they rear up their hindquarters. If so, then they are sawfly larvae. The second step is to identify the plant on which they are feeding. As mentioned earlier, sawflies tend to feed on the plants that coincide with their names: the Apple Sawfly will feed on apple plant leaves and so on. This species, however, can bore into young apple fruits as well.
That being said, here are several methods you can use to control and get rid of sawflies from your garden:
Knock the Sawfly Larvae Off Trees:
Remember when we asked ‘does a sawfly sting?’ It only goes to reason that if fully grown sawflies do not sting then their larvae are also pretty harmless to humans. This means that you can easily and safely use your hands to knock them off leaves and plants. Here is what you should do:
- Lay a sheet on the ground below the infested plant.
- Shake the plant stem, leaves or branches that have sawfly larvae on them.
- When the sawfly larvae fall down, they will fall on the sheet that you have already put down around the plant.
- Gather the fallen larvae and destroy them by burning or drowning in soapy water.
This is one of the best and safest methods to use when trying to control sawfly infestations and populations. It is best to try this method when the infestation is still in its early stages.
As soon as you spot sawfly larvae on your plant leaves, you should immediately employ this control measure. In fact, when there are just a few sawfly larvae around, you can easily pick them off one by one.
How to Get Rid Of Sawflies
If, however, you realize too late that you have a sawfly infestation on your hands, then the next best thing to do is to start employing eradication methods. Here are some tips on how to kill sawflies:
Use Natural Predators:
For the most part, when dealing with infestations, your first course of action should always be to look for natural and environmentally-friendly ways to eradicate the pests in question. Sawflies are some of those pests that have natural predators you can use. Some natural enemies that pose a threat to sawflies include parasitic insects such as parasitic wasps. Having some of these in your garden is a wonderful way to not only control sawfly populations, but to eradicate them as well.
How to Attract Parasitic Wasps
Parasitic wasps have a sadistic way of keeping sawfly populations to a minimum. They lay their eggs inside the sawflies and, as their young grow, they feed on the host pest eventually killing it. The best way to get parasitic wasps into your garden is to plant nectar or pollen-producing plants alongside your typical crops.
You could also buy a few live parasitic wasps and insects from a well-known breeder in your area or online. The best time to do this is during spring when the parasitic wasps lay their eggs in your unwanted sawfly pests.
Use Insecticides to Kill Sawfly Larvae:
Another option would be to use insecticides to kill sawfly infestations. You can easily use a combination of Insecticidal Soap and Botanical Pyrethrins to kill sawfly larvae. This soap is perfect because it penetrates the insect’s outer shell and dehydrates it thus eventually killing it.
You could also use a derivative of the Neem Tree known as Azadirachtin. This a highly effective insect growth regulator that disrupts as well as speeds up the molting process of sawfly larvae. It acts by killing the insects when they try to molt too soon. The best part about using this is that it works on sawfly larvae as well as the larvae of other pests that might be infesting your garden.
Here are other eradication options you could try:
- Use Diatomaceous Earth: this gives you a long-lasting effect on pest control.
- Hose down the larvae: this is similar to shaking them or picking them off the leaves.
- Use Monterey Garden Insect Spray: many farmers have reported a good range of success when using this product.
- Try crop rotation: this is always a good idea when it comes to the control and eradication of common pests.
If all else fails or if you are not convinced that you are doing a good job of eradicating the sawflies yourself, then you can always call a pest management professional.