There are many ways that biological practices may be used to help care for and maintain a lawn, thereby reducing the dependence on traditional insecticides. Listed below are some items which may be considered in an IPM (Integrated Pest Management) program.
Milky Spore - Popular with home lawn enthusiasts, milky spore disease is sold commercially across the country. Bacillus popillae, a specific type of bacteria, is used for Japanese beetle grubs. Grubs infected with the bacterium become white or "milky" in appearance. The spread of the bacterium is more effective in warm soils. Also, it is not effective on other problem white grubs such as Oriental beetles or European chafers.
Endophytes - Endophytes are fungi which are seed-borne and live within the grass host plant. Specific strains have been isolated from tall fescues, fine fescues and perennial ryegrasses. To date, endophytes have not been found in Kentucky Bluegrasses or creeping bentgrasses. Endophytes derive nutrition from the grass host and when infected, the host exhibits improved vigor, drought tolerance and, in some cases, improved disease performance. Grasses with a high percentage of endophytes have been observed to suppress populations of surface feeding insects such as chinch bugs, sod webworms and billbugs. Viability of the endophyte decreases with time. Storage of seed in warmer temperatures will more quickly decrease endophyte viability. Therefore, it is recommended that seed infected with grass endophytes be used within the current year. Also, grasses which contain endophytes are not recommended for pasture areas used for grazing animals such as cattle or sheep.
Nematodes - High populations of some species of nematodes have long been considered destructive to grasses. However, entomopathogenic nematodes are nematodes that carry bacteria inside their guts. When this bacteria comes in contact with a target host via the nematode infection, the bacteria is released in the host and cause its death. Presently, grass insect populations of sod webworms and cutworms can be controlled via entomopathogenic nematodes (Steinernema carpocapsae). In general, nematodes are applied in a suspension and have the potential to desiccate easily if not kept moist. It is important that the nematodes reach the moist soil before this can occur. Research is ongoing as to the effect of another species of Steinernema which may kill white grubs.
Other - Other biological organisms that may infect a lawn include fungi and beneficial predatory wasps.