What are Nematodes?

Nematodes are microscopic worms that are harmless to humans, animals, plants, and healthy earthworms. Beneficial nematodes aggressively pursue pest insects. When they sense the temperature and carbon dioxide emissions of soil-bome insects, they move toward their prey and enter the pest through its body openings. Beneficial nematodes control grubs that are known to destroy lawns. They are effective against white grubs and the larval or grub stage of Japanese Beetles, Northern Masked Chafer, European Chafer, Rose Chafer, Fly larvae, Oriental Beetles, June Beetles, Flea beetles.

How do I know if I have grubs in my lawn?

White grubs feed on the roots of grasses, so lawns will show wilting and browning of irregular shaped areas. Check the root zone of affected areas for the white, c-shaped grubs. Carefully pull back the sod in suspect areas, in particular the where brown grass meets green grass and look for the grubs. Usually a population of about 10 or more grubs per square foot will lead to browning of the lawn. Another sign of grubs is damage from skunks and raccoons digging up lawns in search of grubs to eat.

Why does my lawn have grubs but not my neighbour’s?

Random chance is part of the answer. But adult beetles usually lay eggs in full sun lawn areas with adequate soil moisture. The masked chafer (annual white grub) and Japanese beetle lay eggs in June and July. So if the weather has been dry, but your lawn is watered and surrounded by dry lawns, it is a prime target for egg laying.

How can I predict if my lawn will have grub damage this year?

It is difficult, as insects can go in cycles and many factors influence the chances of grubs appearing in your lawn. Lots of adult beetles on the lawn in the summer are one indication. Masked chafers, the adult of the annual white grub, are tan beetles active shortly after sundown. Japanese beetles fly during the day and feed heavily on many ornamentals. The presence of the adults and having irrigated lawns surrounded by drier turf increases the chances of grub damage to your lawn. Watch lawns closely starting about mid-June and continuing into September for wilting and browning.

What about using organic controls for grub control?

The glaseri nematodes are specifically used by Environmental Factor service providers because of its superior performance against big grubs in spring. The ideal treatment window is early to mid August with Hb nematodes. The glaseri nematode extends the treatment window for grubs to early October as it has a better performance at a wider soil temperature than Hb nematodes.

How often do I need to use biological control nematodes?

Contrary to what you may hear, in most cases biological control nematodes do not persist for a long time after they are applied. Most of these nematodes can live for only a few wecks at most without their host insect. Biological control nematodes occur naturally in most environments.

Will I see the insects die?

Probably not. In most cases, nematodes will attack and kill the insects under the ground.

So, how will I know if they worked?

There is an element of faith involved. You have to watch and trust that they are working. However, if after a few days the insect damage continues to get worse, additional applications of nematodes may be required.

When is the best time to apply nematodes?

Apply when insects are actively feeding, usually in late April early May until late June. Another application is ideal from mid August through mid October for White grubs. Nematodes infect grubs when soil temperature is between 12 C-30C.