Is there an organic control for ticks?

R.L.New YorkAnswer:Ticks feed on the blood of vertebrate animals, particularly (but not exclusively) mammals. Ticks are also vectors of diseases such as Rocky Mountain Spotted Fever, Lyme’s Disease and others. As with any pest, management should focus on why the pest exists in such numbers. The obvious answer to this question is “habitat.” That is, what animals on your farm (or yard), both wild and domesticated, provide food and shelter to ticks? Ticks have relatively few natural enemies, but the use of predators, parasites, and pathogens has been examined for tick control. Tick predation is difficult to document and observations are sporadic. Most arthropod predators are non-specific, opportunistic feeders and probably have little impact on ticks. Anecdotal reports suggested that guinea-fowl or chickens may consume ticks and impact local tick abundance. A minute parasitic wasp, Ixodiphogus hookeri, parasitizes blacklegged ticks, Ixodes scapularis, in a few areas of New England with superabundant deer and tick populations. However, studies indicated that the usefulness of this wasp to control I. scapularis is very limited. Farmscaping to Manage TicksThere are two aspects of managing ticks on your farm. One aspect is reducing the numbers of ticks through predation or treatment. The second is reducing the number of tick hosts. You may wish to consider keeping a flock of chickens or guinea fowl, as these animals will feed on ticks and tend to keep tick populations in check. They will be most effective in the area immediately around your house and orchard. Other than chickens and guinea fowl, I know of no other effective predators or biological controls of ticks. The Resources section lists two articles about guinea fowl.A long-term approach to the abundance of rodents and small mammals on your farm is to increase the number of small mammal predators, such as hawks and owls. This can be done by providing owl nesting boxes as well as raptor perching poles. Information about owl nesting boxes is enclosed. Keep in mind that increasing hawk populations will affect chicken and guinea fowl populations. Animal populations (e.g. rabbits and deer) will fluctuate year to year, also affecting tick populations.Treatment OptionsThe Resources section provides a source of information about a passive topical treatment device for ticks on animals such as deer. It is essentially a bait station in which the animal’s head and neck is dusted with a pesticide every time the animal attempts to feed. This is not an organic control, although it’s relatively environmentally benign if used with amitraz.Treatment options for domestic animals, such as dogs and cats, can be obtained from your local veterinarian and might include Permaguard (a formulation of diatomaceous that is organically acceptable), or citrus oil (d-limonene) extract.Insect parasitic nematodes have been studied as possible biological control agents. Engorged female black legged ticks are susceptible to certain types of nematodes, but these nematodes are too sensitive to the colder autumn temperatures when the ticks are present. The application of entomopathogenic fungi, however, is a promising approach for controlling tricks. Several fungi have been shown pathogenic to I. scapularis. A perimeter treatment of existing commercial formulations of the fungus Beauveria bassiana and with Metarhizium anisopliae at residential sites has been shown to control I. scapularis in small experimental trials. The EPA has approved M. anisopliae for residential outdoor grub and tick control (Tick-Ex?, an oil formulation, and Taenure?, a granular formulation; Earth BioSciences, Fairfield, CT). At this time, additional trials and commercial development are in progress. Entomopathogenic fungi, applied like a traditional pesticide, may be an option in tick management programs, and an oil-free formulation could meet organic standards. Mycotrol O and Naturalis are commercial formulation of Beauveria bassiana. Tick-Ex? and Taenure?Earth BioSciencesP.O. Box 76426 Sherman Ct.Fairfield CT 06430Fax: 203-256-0464Tel: 203-256-0460erb@taensa.comwww.taensa.comNaturalis-LTroy BiosciencesP.O. Box 7012Chandler AZ 88246Fax: 602-278-0462Tel: 480-940-1745Mycotrol OEmerald BioAgriculture Corp.P.O. Box 275193125 Sovereign Dr., Siute BLansing, MI 48909-0519Fax 517-882-7521Tel: 517-882-7536 Additional products are listed in the IPM Practitioner article listed in the Resources section.Resources:Damerow, Gail. 1992. Gardening with Guinea Fowl. Mother Earth News. August/September. p. 46-51., William. 2004. 2005 Directory of Least-Toxic Pest Control Products. The IPM Practitioner. November/December. p. 19.Sabean, J. 1998. Guinea fowl for tick control. Countryside and Small Stock Journal. May/June. Vol. 82. No. 3. p. 36