Pesticide advancements rise while risks drop

There are some interesting developments in pesticide technology resulting in ‘greener’ products – both new and existing.

EPA’s Conventional Reduced Risk Pesticide Program has been expediting the review of conventional pesticides that meet certain criteria such as low toxicity to humans and nontarget organisms including fish and birds, low risk of groundwater contamination or runoff, low potential for pesticide resistance, demonstrated efficacy and compatibility with integrated pest management (IPM). The goal of this program is to quickly register commercial ‘reduced-risk’ alternatives to riskier conventional pesticides. The ‘reduced-risk’ designation applies only to certain uses of a particular pesticide, which may not be all label uses for that product. Some companies don’t request a review, so lack of the designation shouldn’t necessarily be considered a negative; growers need to consider whether products suit their specific needs when it comes to such criteria as compatibility with use of biological controls.

Since reduced-risk products must be EPA-registered, labels will bear EPA registration numbers. Manufacturers, however, aren’t permitted to label materials as reduced-risk. Endeavor (with active ingredient pymetrozine) and Conserve/Entrust (spinosad), TriStar SL (acetamiprid), Judo (spiromesifen), Hachi-Hachi (tolfenpyrad), and Pedestal (novaluron) insecticides and Floramite (bifenazate), Akari (fenpyroximate) and Shuttle-O (acequinocyl) miticides are the reduced-risk products currently available for use on ornamental plants in greenhouses. There are several reduced-risk fungicides and herbicides labeled for ornamentals as well.

For more on these products, visit http://www.epa.gov/opprd001/workplan/reducedrisk.html.
 

Biopesticides, or biological pesticides as defined by EPA, are “unconventional” pesticides derived from such natural materials as animals, plants, bacteria and certain minerals. These include microbial pesticides containing bacteria, fungi, virus, etc. as the active ingredient; plant-incorporated protectants, i.e. pesticidal substances, which plants produce from added genetic material (such as corn, genetically modified to produce Bacillus thuringiensis toxins); and biochemical pesticides comprised of naturally occurring substances that control pests by nontoxic mechanisms (such as pheromones or some insect growth regulators). Biopesticides must be registered with EPA and therefore will bear EPA registration numbers.

Unlike minimum-risk pesticides, discussed below, inert ingredients are not considered when evaluating whether a product is classified as a biopesticide. For more information on biopesticides, http://www.epa.gov/pesticides/biopesticides/.

Growers may be most familiar with the biopesticide Bt, or Bacillus thuringiensis, which produces various proteins that disrupt the gut lining in and are specific to insects. Various strains are effective against caterpillars, beetles, fungus gnats and (in public health programs) mosquitoes.

These include Bt kurstaki (DiPel Pro, Javelin, Deliver, Biobit) and Bt aizawai for caterpillars (Xentari, Agree), and Bt israelensis for fungus gnats (Gnatrol, Gnatrol WDG).

Other biopesticides labeled for use on or around ornamentals include products containing azadirachtin, an insect growth regulator derived from neem seeds that targets immature insect stages (Azatin XL, Azatin O, Ornazin, AzaDirect, Molt-X, Azatrol, AzaSol, AzaGuard), neem oil (Triact 70), iron phosphate for slugs or snails (Sluggo). Several insect-killing fungi are included as biopesticides, such as Beauveria bassiana GHA for whiteflies, thrips and other pests (BotaniGard ES and WP); Isaria fumosoroseus Apopka strain 97 (Preferal) or Paecilomyces fumosoroseus FE9901 (NoFly) for whiteflies and others; and Metarhizium anisopliae F52 (Met52 EC or G) for black vine weevil, thrips, and others.

Oriental Beetle MD is a pheromone product used for controlling oriental beetle, a grub pest of container-grown plants (and also turf) in some regions. It is one of the few materials available to growers of ornamentals for controlling insects via mating disruption. Several other notification-exempt biopesticides are labeled as animal (e.g. deer) repellents, herbicides and fungicides.

Exempt from EPA registration, the so-called minimum-risk pesticides carry no EPA registration number. These products contain only active ingredients outlined in FIFRA 40 CFR 152.25(g) (“the 25b list”) and inert ingredients currently identified on Federal Register Notice 59 FR 49400 (“the 4A list”). The 25b list and more information can be seen at http://www.epa.gov/oppbppd1/biopesticides/regtools/25b_list.htm. The 4A list of inert ingredients is at: http://www.epa.gov/oppbppd1/biopesticides/regtools/25b_list.htm.

Minimum-risk product labels must include the name of each inert and active ingredient, as well as the percentage (by weight) of each active ingredient. Labels cannot include claims to protect human or public health or to control rodent, insect or microbial pests in a way that links the pests with any specific disease.

Products used for public health must show evidence that they are effective against the target pest. Products intended for use on food plants have additional requirements. Some states add further restrictions, e.g. New York requires minimum-risk product labels to display pesticide use directions, with percent concentrations of all ingredients. Policies may differ in other states, which may require such products to carry a state registration number. Examples of minimum-risk pesticides include Pest Out (containing active ingredients cottonseed, clove and garlic oils), Cedar Gard (cedar oil), and Essentria IC³ (rosemary and peppermint oil, geraniol).

Be sure any insecticide or miticide used in production complies with WPS labeling and requirements. It is very important to test any new product across all varieties on a small scale before using on the entire crop. In my experience there have been cases of sometimes serious plant sensitivity to many minimum-risk products (with no label warnings), as well as to a few conventional insecticides. Try to verify the efficacy of any new product – higher costs may be justified by efficacy, persistence and plant safety.

Though there is still much work to be done, pest management technologies and information have reached well beyond our imagination. Furthermore, they show no signs of stopping. It will be exciting to see where the future takes us.

Daniel Gilrein is a frequent contributor to Greenhouse Management and an extension entomologist at Cornell University Cooperative Extension of Suffolk County.