Mole cricket nematode
A microscopic roundworm from South America that attacks mole crickets and little else. It was brought from Uruguay to Florida in 1985 and was later sold there as a biopesticide, from 2002 as Nematac S. It is no longer on sale. UF/IFAS says it was applied across Florida until 2012 and is not available commercially now. Other accounts put its withdrawal in 2014. The good news is that it persists. It persists readily under Florida conditions, infected crickets carry it to new sites as they fly, and it remains one of the three natural enemies that have brought Florida's pest mole crickets down. You cannot buy it, but in much of Florida it is already there.
At a glance
- Kind
- Established in Florida — not on sale
- Mode
- Insect-parasitic nematode + bacteria
- Origin
- Uruguay, brought to Florida in 1985
- Attacks
- Large nymphs and adults
- Kills in
- Within 12 days of infection (UF/IFAS)
- Persists
- At least 10 weeks in moist soil; years in the field
How it works
As with other insect-parasitic nematodes, the infective juvenile is the stage that lives outside a host. It enters a mole cricket through the mouth or spiracles and kills it, and the nematodes breed inside the body. At 24 °C (75 °F) one cycle takes about 8–10 days, or 6–7 days when food is short or the host is crowded, before a new generation of juveniles leaves to find more hosts. UF/IFAS gives infected crickets as dying within 12 days.
What sets it apart is how it spreads. Mole crickets infected early keep flying, and they carry the nematode with them. After the first release in Alachua County in 1985, UF/IFAS found infection rates of 25–65% at a farm 10 miles away within five years. Field samples consistently find 10% or more of mole crickets infected, and in a five-year study that level cut nymph numbers by about 85% after one year and by 95% or more after that. In 1990 and 1991 it was released in pastures in six counties and on nearly 30 Florida golf courses. Becker Underwood began selling it as Nematac S in 2002, and in about a year more than 50 billion nematodes were applied to pastures, golf courses, sod farms and landscapes in 20 Florida counties.
What it is confused with
Nothing on a garden-centre shelf is this nematode. The beneficial nematodes sold for lawns are different species, with different hosts.
- Also goodSteinernema carpocapsae — Sold widely for lawn caterpillars and billbugs, and some suppliers list mole crickets too; it is a generalist, not the mole cricket specialist.
- Also goodHeterorhabditis bacteriophora — The grub nematode. It is sold against white grubs, weevils and other soil insects; suppliers such as Buglogical do not list mole crickets among its targets.
How to keep it around
You cannot buy it or call it in, but where it already lives you can avoid undoing the work. UF/IFAS advice for keeping mole cricket natural enemies in place:
- Treat only where needed and leave some areas untreated so natural enemies survive; UF/IFAS gives golf roughs and driving ranges as the example
- Soap-flush first: UF/IFAS gives 2–4 adult mole crickets per 4 ft² as a general upper limit for turf, with higher thresholds usual in pasture
- Plant larraflower, white pentas or partridge pea for the Larra wasp, the nematode's partner in Florida's programme
- Keep in mind that it depends on soil moisture: UF/IFAS found it stays infective for at least 10 weeks without hosts in moist soil
Pesticide sensitivity
No published compatibility table was found for this species, so how it fares after soil insecticide drenches was not traced for this page. Open the compatibility matrix →
When to choose something else
This is the right answer only in Florida and a few neighbouring areas where it is already established. Look elsewhere when:
- You want something to buy and apply — there is no product on sale; UF/IFAS says none of the mole cricket biocontrol agents is available commercially
- You are outside Florida — establishment has been confirmed only in southern Georgia north of the state line
- Your flush count is over threshold now — UF/IFAS Extension in north Florida advises treating in June–July, when nymphs are small; see mole crickets
- The pest is white grubs — use the grub nematode instead
Mole cricket nematode by target
What it eats and when it turns up differ by pest. Each page below is the picture for one target.