Three Newer Biological Insecticides for Vegetable and Small Fruit Growers
Posted: September 23, 2014
Much of the growth in new pesticides has been in the form of biologically-based materials. These pesticides can be sourced from naturally occurring bacteria in products like Dipel, Thuricide, and Javelin, from fungi in products like Botanigard, Met52, or PFR-97 or through the fermentation processes of two species of Saccharopolyspora bacteria like SpinTor*, Entrust and Conserve. As a rule, biologically-based pesticides go through a substantially faster review process at the EPA than conventional materials made through more traditional typical chemical processes. In this article, we will review how Met52, PFR-97 and Grandevo work (their modes of action) and where they may fit into your pest control strategies.
- Active Ingredient: Chromobacterium substsugae strain PRAA4-1 and spent fermentation media.
- Grandevo is labeled for use on Asparagus, Cole Crops, Alliums, Bushberries, Caneberries, Sweetcorn, Cucurbits, Tomatoes, Peppers, Eggplants, Tomatillo, Grapes, Most Herbs, Hops, Most Leafy Vegetables, Beets, Turnips, Legumes, Most Roots and Tubers, and Strawberries.
- Pests controlled include: Aphids, Armyworms, Cutworms, Whiteflies, Diamondback Moth, Cabbageworms, Thrips, Leafhoppers, Fruitworms, Corn Borers, Corn Earworms, Mites, Psyllids, Leafrollers and Plant bugs. This is a slightly abbreviated list, see the label for a more detailed listing.
- REI: 4 hours, PHI: 0 days.
- Rate of application: between 1lb and 3lb per acre depending on the crop and pest being treated.
- Grandevo is OMRI listed and NOP approved.
- Grandevo functions primarily as a stomach poison, so it must be ingested by insects and mites to be effective. It does not have systemic activity; therefore, it must be on the feeding surfaces to be effective. Like other stomach poisons, excellent plant coverage is necessary, so use plenty of water and pressure to get complete coverage. Grandevo is more effective on newly hatched larvae and nymph stages of insects and arthropods, so regular scouting and early applications are necessary for good control.
- Active Ingredient: Metarhizium anisopliae Strain F52
- Met52 is labeled for use on Onions, Celery, Lettuce, Spinach, Peppers, Tomatoes, Grapes, Strawberries, Caneberries, Raspberries and Blackberries.
- Pests controlled include: Thrips, Whiteflies, Mites, and Weevils.
- REI: 0 hours when soil incorporated and 4 hours when applied to the foliage
- PHI: 0 days.
- Rate of application: Drench: 40-80 oz. /100 gal. Foliar: .5pt to 2 qt. / acre.
- Met52 does not appear to have a U.S. organic label at this time.
- Met52 functions as a contact insecticide. Spores and or mycelia from the pathogenic fungus M. anisopliae that come in contact with insect penetrate the insect’s exoskeleton and grow with the haemolymph (insect’s blood) killing the insect or mite. The spores / mycelia do not need to be ingested, but must come into direct contact with the pests. Upon application, the spores / mycelia attach to the insect or mites cuticle. The spores / mycelia then germinate and form an appressorium which penetrates the pest’s cuticle. Blastospores are then formed in the haemolymph (insect’s blood) which circulates and begins a systemic infection which kills the insect in 4-5 days. Under higher humidity conditions such as in a greenhouse or high tunnel, it is possible to get reinfection of other pests as fungal hyphae emerge from the exoskeleton of infected insects or mites and release new spores into the environment.
- Active Ingredient: Isaria fumosorosea Apopka Strain 97.
- PFR-97 is labeled for use on vegetable and strawberry transplants, strawberries, grapes, sweet corn, leafy vegetables, cucurbits, potatoes, beans, and herbs.
- Pests controlled include: Black Vine Weevils, Thrips pupae, Rootworms, Wireworms, Beetle grubs and larvae, Lepidopteran caterpillars, Whiteflies, Aphids, Thrips, Spider mites, Broad mites, Rust mites, Leafminers, Mealybugs, Plant Bugs, and Psyllids.
- REI: 4 hours, PHI: 0 days
- Rate of application: 1lb – 2lb / acre for outdoor grown crops. Greenhouse production of transplants: 14-28 oz per 100 gallons applied to the foliage. Drench applications for soil surface and root feeding pests 14-28 oz./ 100 gallons with specific volumes applied per pot based on volume (see the label for these rates).
- PFR-97 is OMRI labeled and NOP approved.
- The fungus in PFR-97 infects both foliar and soil dwelling pests. Similarly to Met-52, it attaches to the insect or mite’s cuticle, germinates, and then penetrates into the insect’s or mites exoskeleton. Once inside the fungus continues to grow until it ultimately kills the insect or mite. Under high humidity conditions the white mycelia growth from this fungus will emerge from the dead insect / mite and will release more spores into the environment that can subsequently infect other insects / mites. As per the pesticides’ label, PFR-97 is considered to be safe for use around bees and other beneficial insects. PFR-97 should not be tank mixed with fungicides, but it can be used with IGR’s (Insect Growth Regulators such as buprofezin.
*SpinTor is no longer on the market, but is used here as an example as it has been a highly effective tool for growers and is relatively well known in the industry. Both Conserve and Entrust contain the same active ingredient as SpinTor and are still readily available through your local pesticide dealer. Conserve is labeled for greenhouse and ornamental use and Entrust has an OMRI label and can be used on a wide range of food crops. The insecticide Radiant has a similar mode of action as the spinosyns’ Conserve and Entrust, and can be used outdoors on a wide range of vegetable crops.
With insects such as Western Flower Thrips (WFT) developing resistance to many of our traditional classes of insecticides, these biologically-based materials and their novel modes of action show great promise as tools in our IPM toolbox. If you plan to incorporate these insecticides into your pest management program remember to scout your crops frequently, to develop a management strategy ahead of time for common pests such as spider mites on greenhouse or high tunnel tomatoes and to trial these newest biological tools in your operation to learn when and how to use these pesticides effectively
For additional information on these insecticides and other biologically-based pest and disease management strategies consider attending the Penn State Extension program ‘Advanced Topics in BioControls’ at the Lancaster Farm and Home Center, Lancaster PA on November 13 & 14, 2014. http://www.cvent.com/events/advanced-topics-in-biocontrols/event-summary-1d9368adf67c4122aea0e864045bce84.aspx