SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: http://read.dmtmag.com/i/484138
10 SportsTurf | April 2015 www.sportsturfonline.com Field Science a true biological control, the Bt bacteria would grow within the insect, take over the body and kill it. If an insect ingests live Bt bacteria, the gut enzymes will kill and digest the bacterium, thereby releasing the toxins. Among the scientific community, biobased also includes toxins that can be derived from plants (botanical pesticides), and fungi. Using this definition, cedar oil, garlic extract, pep- permint extract, pepper extracts, etc. are technically biobased, but none of these, by themselves or in combination, seem to have much effect on most turfgrass insect pests. I mention these because organic pesticide products are on the market that claim efficacy against turf and ornamental insects and mites. Since these two areas are not human health issues, EPA has turned a blind eye on requesting efficacy data! When asked, the suppliers of these products are quick to provide all kinds of testimonials, but can't provide independent testing results (preferably by a university-based turf researcher). Buyer beware! Synthetic, natural and organic? Synthetic generally means that the pesticide is completely made using laboratory chemical methods. Natural simply means that the biological control or biobased chemicals are naturally occurring in nature. "Organic" means that the pesticide has passed the organic standards set by the USDA and the Organic Material Review Institute (OMRI). This can get confusing as you can have the same biobased insecticide being non-organic or organic depending on the formulation. As an example, azadirachtins are chemicals extracted from the neem tree that have insect repellency and growth regular effects. If you use Azatrol, the product is not organic because this formulation uses synthetic emulsifiers and stickers in the formulation. However, if you use NeemAway, the product uses natural surfactants and stickers and it has OMRI certification. Being "natural" and/or "organic" does not mean that the chemical is low in toxicity! Rotenone, a botanical insecticide derived from tropical plants' roots, was considered organic, until testing found that it was a relatively toxic general metab- olism inhibitor. It is now banned in Europe and the United States for insect control. What WorkS: biological controlS As previously stated, the insect parasitic nematodes area prob- ably the best of the true biological controls for use in turfgrass, but expensive. There are numerous species and strains on the market, but I can distill them down to two groups— nematodes that are best to control caterpillars and nematodes that are best for soil-dwelling pests like billbug larvae and white grubs. Nematodes in the genus Steinernema are general parasites that are very good at finding sod webworm and cut- worm larvae. When billbug larvae are near the soil surface, The target of any grub control material should be the tiny first instar. The second instar is relatively easy to kill, but the third instar is difficult to control even with the best of materials! LEFT: Bluegrass billbug damage often is mistaken for summer drought or disease. If not controlled, these spots will eventually die. RIGHT: Billbugs have a complete life cycle with egg, larval, pupal and adult stages. The smaller larvae are easier to control targets. Bluegrass billbug larvae burrow down the seedhead stem to the crown. When they devour the crown, the plant will be killed.