Rick Weinzierl.

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1 Organic Insecticides Rick Weinzierl University it of Illinoisi

2 Organic insecticides OMRI Organic Materials Review Institute org/ Organics offer benefits if: They are less persistent in the environment They are less toxic to non-target t organisms More specific modes of action Examples include: Botanical insecticides Synergists may be beneficial but most are not OMRI-listed Soaps and oils Microbial insecticides Growth regulators Pheromones

3 Botanicals Prepared from plants Crude dusts or powders (pyrethrum) Extracts or resins (pyrethrins, neem seed oils) Isolated, refined components (d-limonene, linalool) Always -- minimal alteration of naturally occurring compounds Strengths and weaknesses Rapid action Rapid degradation Low toxicity to mammals (in general, not always) Minimal technology required for preparation

4 Older botanicals and their origins Nicotine Nicotiana spp. Pyrethrins Chrysanthemum cinerariaefolium Rotenone Derris, Lonchocarpus and other legumes Sabadilla Schoenocaulon officinale (a tropical lily) Similar veratrine alkaloids in white hellebore, Veratrum album Ryania Ryania speciosa Others Soaps, horticultural oils, essential oils, diatomaceous earth

5 Modes of action, toxicity, and uses Nicotine Acetylcholine mimic Toxicity: Mod-High Greenhouse / (dermal and oral) Homoptera Pyrethrins Na+ / K- ion trans in axons Toxicity: Low Animals, humans, organic crops Rotenone Electron transfer in cellular respiration Toxicity: Moderate (implicated in Parkinson s disease) Beetles in organic crops Sabadilla Nerve membrane function Toxicity: Low (but mucous membrane irritant) Squash bug Ryania Calcium channel disruptors (axonic) Toxicity: Low Beetles, caterpillars in organic crops

6 Regulatory and marketing status t of older botanicals in the United States Only ypyrethrins are widely available with labels covering a range of crop, animal, indoor, and human uses

Garlic oils Hot pepper oils Soaps Microbials Toxins from Bacillus thuringiensis and other soil

7 More recent botanicals (and similar ingredients) and microbials and their origins Linalool and d-limonene citrus oil derivatives Neem Azadirachta spp. and Melia spp. Garlic oils Hot pepper oils Soaps Microbials Toxins from Bacillus thuringiensis and other soil micro-organisms organisms (avermectins, spinosyns); also other pathogens Azadirachta windbreak. (E. Fernandez, ecf3/web/new/af/arid.html)

8 Modes of action, toxicity, and uses Citrus derivatives Nerve cell stimulants Low On pets, indoor plants Neem Multiple actions, ecdysone agonist Very Low (medicinal uses) Many crop pests Garlic oil? Low Many labeled uses, limited positive Hot pepper extracts Soaps? Low Membrane disruptors (including tracheae) Low data on effectiveness Effective against soft-bodied pests (aphids, mites, etc.) Microbials Multiple Low Many for Bt and other products

9 Regulatory and marketing status t in the United States Limonene and linalool Neem Garlic oil Hot pepper extracts Many labels, not all are OMRI-listed Used primarily in organic production of high-value crops Homeowner products Efficacy is questionable

10 Effectiveness of currently available botanicals Older botanicals Generally well understood based on field trials and small plot trials from 1920s through 1950s More recent products More unsupported label claims

11 Botanicals Pyrethrins From pyrethrin daisies Axonic poisons Low in toxicity to mammals Very rapid breakdown... no residual action Used to kill fleas and lice on humans and pets; labeled for use on many fruits and vegetables Rotenone From roots of Derris and other tropical legumes Disrupts cellular respiration Moderate toxicity to mammals (~ Sevin); very toxic to fish Moderate persistence (~ Sevin) Used against many pests, especially beetles No longer on the NOP list of approved materials

12 Botanicals Sabadilla From seeds of a tropical lily & European Veratrum spp. Axonic poison Very low in toxicity to mammals, but a severe membrane irritant Breaks down very rapidly Effective against squash bug, harlequin bug, and citrus thrips Ryania From woody stems of S. American Ryania shrubs Calcium channel poison Low mammalian toxicity More persistent than rotenone but less potent Used against caterpillars in fruits and vegetables Sabadilla & ryania are not available now

13 Botanicals Nicotine From tobacco, other Nicotiana spp., others Acetylcholine mimic Very toxic to humans, orally and dermally Very short persistence Used in greenhouses against aphids, thrips, and mites Not on the NOP list of approved substances Citronella Pennyroyal Garlic Rosemary oil With peppermint oil in EcoTec AG Hot pepper wax Cedar oil??

14 Botanicals Neem Citrus oil components From all parts of Azadirachta and Melia spp. Ecdysone (molting hormone) )promoters / mimics & molting disruptors Low toxicity to mammals; used medicinally Very short persistence Labeled on many crops and landscape plants, especially against soft- bodied insects Limonene and linalool From citrus oils Very short persistence Low acute toxicity to mammals, but some evidence of chronic toxicity Less toxic than crude citrus extracts Mostly in pet shampoos, etc.

15 Synergists MGK 264 Block metabolism by mixed function oxidases and other detoxifying enzymes, thereby making the insecticide more effective Examples include piperonyl butoxide, sulfoxide, and MGK 264 Most not OMRI-listed Piperonyl butoxide

16 Oils may be vegetable oils or highly hl refined petroleum oils Dormant oils for fruit and landscape trees Against overwintering i aphid eggs, mite eggs, scales Stylet oils reduce virus transmission, may suppress powdery mildew Summer oils Against mites, aphids, other soft-bodied pests Coverage is essential (upper and lower leaf surfaces); oils kill by suffocating pests that are sprayed directly (or by disrupting membrane functions)

17 Insecticidal soaps Salts of fatty acids Kill insects by disrupting membranes (including tracheal linings) Work only against those insects that are wetted by the spray... no residual action Effective against aphids, whiteflies, mites, and other soft-bodied, not-too-mobile pests Best-known brand names are Safer s and M- Pede Make your own? Generally... NO!!!

18 Absorbents & abrasives Clays, diatomaceous earth, silica aerogels disrupt the insect s cuticle and kill by dehydration Kaolin... Surround

19 New Investigations Pea flour Paw paws Calotropis (milk weed) Sesqueterpene carboxylic acids from tomato Piperaceae Piper nigrum (Many others) /EEB271/Piperaceae/

20 Piper spp. (Piperaceae) extracts t against European chafer in turf grass Scott (Univ. of Ottawa) et al., 2005, J. Econ. Entomol. 98: Extracted principal piperamide (piperine) from seeds and other tissues Determined LC 50 s and conducted filed trials Effective against European chafer larvae in field trials Half-life in soil = days More toxic to earthworms than diazinon

21 Future integration of botanical insecticides into pest management programs Effectiveness Need for funded studies of efficacy Not always part of small company s plans Consistent and economical production Different standards for high-value versus low-value crops and settings Different standards for developed versus developing countries Regulatory approval Reduced d risk track in the U.S. Registration still required in nearly all instances Appropriateness to scale and value of target crop

22 Insect pathogens Viruses Bacteria Bacillus thuringiensis (various subspecies) Fungi Beauveria, Entomophthora, and Metarrhizium spp. Protozoa Nosema spp. Nematodes Steinernema & Heterorhabditis

23 Microbials Bacillus thuringiensis kurstaki and aizawai Toxic only to Lepidopteran larvae (caterpillars) Must be ingested to be effective Degraded by ultraviolet light... short residual activity on treated t foliage Good targets: Leps on cabbage, hornworms and fruitworm on tomatoes, European corn borer on sweet corn, etc. Not effective against: larvae that bore or tunnel into plants without much feeding on the surface Dipel, Agree, XenTari, and many others

24 Microbials Bacillus thuringiensis tenebrionis effective against Colorado potato t beetle larvae Bacillus thuringiensis israelensis effective against larvae of black flies, fungus gnats, and some mosquitoes Bacillus popilliae and Bacillus lentimorbus effective against larvae of Japanese beetles (but not very effective against other white grubs) Trade Names include Doom, Japidemic, Milky- spore

25 Microbials Viruses Commercial products that target codling moth, corn earworm, and gypsy moth are available Fungi Beauveria, Entomophthora, and Metarrhizium spp. Mycotrol and Botanigard Protozoa Nosema spp. NOLO bait for rangeland grasshopper suppression Nematodes Steinernema & Heterorhabditis Biosafe, Bio Vector, Nemasys

26 Microbials more or less Spinosads including SpinTor and Entrust by Dow Derived from a soil actinomycete Effective against a range of insects, including corn earworm, Colorado potato beetle, the worms on cabbage and related cole crops, apple maggot, and (less so) codling moth At least a portion of the activity of the spinosyns results from their functioning as mimics of acetylcholine.

27 Microbials more or less Avermectins From Streptomyces t avermitilis, a Grampositive soil bacterium Block nerve transmission that is mediated by GABA... more common in insects and mites than in other animals. These compounds are GABA "agonists"... promoters. Commercially available as Ivomec, Agri-Mek, others. None are OMRI-listed

28 Pheromones for direct control Removal trapping Mating disruption Sustained release dispensers, sprayable formulations, aerosol puffers

29 Organic insecticides: id Botanicals, microbials, and other alternatives Appropriate IF... they are low in toxicity it to non-target t organisms ( selective ) they do not persist in the environment (and are not moved to unwanted destinations) Selectivity and short persistence are weaknesses as well as strengths

30 Elemental and naturally occurring chemicals Sulfur effective miticide (may cause plant injury) Copper Arsenic

31 Alternatives in Insect Management Biological and Biorational Approaches / i t / t t / l

Natural Insecticides. Eileen Buss, Ph.D. Entomology & Nematology Dept., UF/IFAS ;

Natural Insecticides. Eileen Buss, Ph.D. Entomology & Nematology Dept., UF/IFAS ; Natural Insecticides Eileen Buss, Ph.D. Entomology & Nematology Dept., UF/IFAS 352-273-3976; eabuss@ufl.edu Learning Objectives Know the major categories of natural products and microbial insecticides;