Understanding Pesticides: Types, Usage, and Environmental Impact

1. The other “–icides” Rodenticides Molluscicides Predacides Avicides Animal Repellants Fungicides Piscicides

2. Rodenticides • Coumarin (Warfarin and Ratoxin) • Primary target rats and mice • Anticoagulant • Require repeated feeding to work • Broad spectrum – can affect cats, dogs and people – care must be taken to preclude exposure of non-target species • Degrade is slow in the environment • Generally in bait stations or other self-contained medium so, despite persistence, environmental contamination is improbable

3. Rodenticides • Brodifacoum (Talon & d-con) • Primary target rats and mice • Anticoagulant • Requires only a single feeding to work • Broad spectrum – can affect cats, dogs and people – care must be taken to preclude exposure of non-target species • Degrade is slow in the environment • Generally in bait stations or other self-contained medium so, despite persistence, environmental contamination is improbable

4. Rodenticides • Chlorophacinone (Rozol) • Not targeted specifically for rats & mice • Anticoagulant • Requires only a single feeding to work • Broad spectrum – can affect cats, dogs and people – care must be taken to preclude exposure of non-target species • Degrade is slow in the environment • Generally in bait stations or other self-contained medium so, despite persistence, environmental contamination is improbable

5. Rodenticide, Predacide, & Avicide • Strychnine (natural alkaloid extracted from Strychnos nux vomica) • Used in FS western regions to control plague vectors • Requires only a single feeding to work • Broad spectrum – can affect many non-target species – care must be taken to preclude exposure of non-target species • Degrade is slow in the environment • Generally in bait stations or other self-contained medium so, despite persistence, environmental contamination is improbable • RESTRICTED-USE – may be legally applied only by certified professionals

6. Molluscicides & Avicide • None currently in use in forestry. • Slug control (molluscicide) or bird control • Methiocarb (Mesurol) • Has some insecticidal capacity also • Slow degrade

7. Animal Repellants • Thiram • Effective rodent repellant • Only one known to have been used by the FS in the southeast • Use rare – generally associated with rabbit dispersal in regeneration areas

8. Animal Repellants • Complex polysaccharide mix (Ro-Pel) • Effective against birds, rodents and mammals • Low impact on target species • Low negative impacts on non-targets • Relatively rapid and complete degrade

9. Animal Repellants • Putrescent egg solids (BGR [Big Game Repellant]) • Effective at preventing grazing by deer and elk • Bloodmeal (Plantskyyd) • Deer, rabbit and elk are specifically noted – regeneration, primary used as a protectant of the seedlings • Bloodmeal and putrescent egg solids are on the EPA list of minimum risk pesticides

10. Animal Repellants • Capsacian (various Hot Sauce…; Active ingredient derived from tobasco peppers) • Effective against many large mammals

11. Fungicide and Rodent Repellant • Thiram • Used primarily in nurseries to prevent needle diseases and also to dissuade rodent feeding on seedlings

12. Fungicides • Borax (Sporax) • Primary use is to prevent colonization of pine stumps by Heterobasidion annosum, cause of annosus root disease • Little activity against non-targets other than other fungi • Barrier or preventive only, not therapeutic if infection already exists

13. Fungicides • Captan and Ferbam • Used primarily in nurseries to prevent damping-off of seedlings (root and root collar fungal attack) • Sometimes ferbam is used over-the-top on seedlings as a preventive treatment against fusiform rust infection

14. Fungicides • Triadimefon (Bayleton) • Used in nurseries to prevent needle blights • Primary use in the Southeast has been to prevent fusiform rust infection of pine seedlings • Also used as an additive in root dip slurries to confer anti-rust protection to pine seedlings being outplanted

15. Fungicides • Propaconizole (Alamo) • Primarily used as a therapeutant for trees affected by oak wilt • Application is by injectioin which can cause damage to the tree • About a 75% effectiveness on treated trees, but only effective against current infection, no prevention/protectant benefit

16. Fungicides • Phlebia gigantea • Fungus effective in reducing the future effect of annosus root rot in stands infected by Heterobasidion annosum prior to harvest • NOT REGISTERED • Previously used under permissive 1970’s letter from the EPA as an augmentive treatment (Pg is common in the woods) • Letter revoked in late 1990s and only low probability of registration

17. Fungicides • Copper sulfate (Bordeaux Mixture & others) • Oldest of the fungicides, this classic is effective against many mildews and other needle blights • Use in nurseries has been relatively minor

18. Fungicides • Benomyl (Benlate) • Used in nurseries as a seedling protectant • Last of the forestry registrations for this product were cancelled in 2001 • May use existing stocks, but no new product will become available

19. Piscicide • Rotenone • Previously discussed See… Rotenone in the aquatic pesticide section