Digger wasps are continuing to multiply in numbers in the Lowcountry. At Possum’s we used to get a few complaints in localized areas, now the numbers seem to be on the rise. One faithful reader of the ‘Horticulture Hotline’ sent me a 14 page letter describing the progression of damage to her yard. The presence of wasps is intimidating and unsafe.
Digger wasps start out as just a few holes in the yard. The holes are where the adults lay their eggs. In the spring, the young emerge. In the fall these wasps are now adults and they dig new holes and lay eggs for the following spring. In a very short time period, you can go from having a few digger wasps to thousands. All these holes can ruin your turf areas and the wasps make it less enjoyable to be in the yard.
Most of these wasps are predatory feeders. They eat grubs (should manage for moles and potential turf damage), small flying insects and ground dwelling insects (mole crickets, etc). The wasps sting the prey to death, then bring the dead prey back to the wasp’s hole (nest), then lay an egg on it so the young has an instant food supply when it hatches.
All control should be done at dusk or at night when the wasps are in their hole. You need to plan on several applications of products to manage this pest. Since the wasps eat insects in your yard that you should be managing to certain thresholds, going after the wasp as well as their food source should benefit you greatly. Since the wasps like subsurface insects, Sevin would be a good product to start your management program.
If you just have a few holes, Delta Dust is a great product. At night treat in and around the hole. Some people will also “plug” the hole. At Possum’s we sell the plugs, but you could possibly use something from around the house. Be sure to turn off the irrigation and check for rain.
If you have many of these uninvited guests, DeltaGard G or Turf Ranger could be used across the whole area. Remember they fly, so getting your neighbors involved is crucial. These products need to be watered in to get to the target. Turf Ranger recommends ½ inch of water. Water the product in slowly so the product soaks into the ground, and does not run off into a non-target area. Apply these products when you first see the wasps and until they are gone, waiting at least one week between applications.
Essentria IC3 is a National Organics Program compliant product that is labeled for wasps and other small flying insects (mosquitoes – yeah). IC3 is safe to use around water, kids, and pets. Consider using IC3 in your product rotation.
When treating always wear dark clothes and have a can of wasp freeze on your person. Digger wasps did not get there overnight, and they are not going to go away overnight.
Always read, understand and follow product label. The product label is a Federal Law.
Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at http://www.possumsupply.com. You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA (The Big Talker). The Horticulture Hotline is available 24 / 7 at possumsupply.com.