Can you help me identify if these are Cranefly Larvae ?? - Ask Extension
Hi, I found these in my raised veggie garden under some broccoli and a weed I pulled out to start refreshing for new plants. I thought they were grubs...
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Can you help me identify if these are Cranefly Larvae ?? #866822
Asked May 02, 2024, 6:09 PM EDT
Hi, I found these in my raised veggie garden under some broccoli and a weed I pulled out to start refreshing for new plants. I thought they were grubs at first but friends are suggesting maybe cranefly leatherjacket larvae. I haven’t even gone through my whole garden bed but these were all found within an inch or two of the top of the soil in a very small area. I need help identifying and how to treat them. I’m guessing they are under my grass soil also where dead spots are. Help.
Wayne County Michigan
Expert Response
These are definitely not grubs.
They could be cranefly larvae but could also be another type of fly larvae. It is difficult to identify fly larvae to species for even an experienced entomologist. The timing is certainly correct for cranefly larvae.
I'd suggest visiting the spot at night with a flashlight (when they are active) to check again if any return to the surface or the roots to feed. Any more than 15 larvae per square feet will likely damage turf. Damage would appear as thinned areas that appear brown in the lawn.
The first steps to manage cranefly are keeping the lawn fertilized, reducing irrigation frequency (they prefer moist soils) when possible, and keeping the mower height at 2 - 3 inches.
Insecticides applied now will have less of an effect because the cranefly larvae are nearer to the end of their immature life stage. A late Sep/early Oct application of an insecticide with one of the following active ingredients will prevent damage in the next season: Chlorantraniliprole, carbaryl, clothianidin. Insecticides with the active ingredient of dinotefuran can be applied now. However, these formulations for lawns may only be available to licensed pesticide applicators. If you choose to use an insecticide, always read the label and follow instructions.
They could be cranefly larvae but could also be another type of fly larvae. It is difficult to identify fly larvae to species for even an experienced entomologist. The timing is certainly correct for cranefly larvae.
I'd suggest visiting the spot at night with a flashlight (when they are active) to check again if any return to the surface or the roots to feed. Any more than 15 larvae per square feet will likely damage turf. Damage would appear as thinned areas that appear brown in the lawn.
The first steps to manage cranefly are keeping the lawn fertilized, reducing irrigation frequency (they prefer moist soils) when possible, and keeping the mower height at 2 - 3 inches.
Insecticides applied now will have less of an effect because the cranefly larvae are nearer to the end of their immature life stage. A late Sep/early Oct application of an insecticide with one of the following active ingredients will prevent damage in the next season: Chlorantraniliprole, carbaryl, clothianidin. Insecticides with the active ingredient of dinotefuran can be applied now. However, these formulations for lawns may only be available to licensed pesticide applicators. If you choose to use an insecticide, always read the label and follow instructions.
Thank you so very much for this detailed response! I am wondering if you know also if there’s something. I should do to my raised garden bed I found them in before planting. We’ve mixed up the soil and I’ve dug out as many as I’ve seen but I am worried if I plant they may eat everything. I appreciate your time!
I wouldn't recommend doing anything different. Just keep an eye on the area. Cranefly larvae are often scattered rather than widespread.
Okay. Thank you so very much this was very helpful!
