Mike’s Q & A: Grub Worms & Nematodes

Grubs Treated with Nematodes

We are getting many questions about grub worms in the soils now, particularly with our record rainfall.  The grubs in the soil now are changing into some type of beetle most likely the June beetle. Adults begin to emerge in spring. During adult flights large numbers of beetles can be attracted to lights. Peak flights occur in mid to late June in central Texas. Females, less attracted to lights, tunnel 2 to 5 inches into the soil and deposit eggs. In 3 to 4 weeks, small grubs (larvae) hatch from eggs and start to develop and eat.

At this time in the life cycle, a grub killer should be applied to the lawn and flowerbed areas. The insecticides imidacloprid and halofenozide are used mostly for white grub control. Imidacloprid is most effective against smalland medium-sized grubs but may kill some grubs larger than 1/2 inch long. Imidacloprid trade names include Merit®, Bayer NGANTidoteAdvanced Lawn™ Season Long Grub Control and Scott’s® Grub-Ex®. The lethal effects of the insect growth regulator halofenozide are limited to early white grub life stages. Halofenozide is ineffective if applied too late, after grubs have reached the third-instar life stage. Halofenozide products include Spectracide® Grub Stop™ and Hi-Yield® Kill-a-Grub™. For the organic lawns use Beneficial Nematodes. Russell Feed carries Nature’s Guard ANTidote Beneficial Nematodes.

Nematodes are tiny worms that attack white grubs and other soil inhabiting insects.  Nematodes must be supplied with adequate moisture to help them move down into the soil where grubs are feeding. At least 1/4 inch of water should be applied before, and another 1/ 4 inch of water applied just after, nematodes are sprayed on the lawn. These worms pose no threat to humans or landscape plants and are an environmentally sound alternative for those who prefer not to use pesticides on their lawn.  Visit Russell Feed & Supply stores or contact us today with any questions you have regarding insect control treatments. We are always happy to help you find an effective solution to maintain a healthy lawn and garden!