Herbivore repellent

Pine oil is a by-product of the pulp industry. This oily liquid contains a mixture of terpene alcohols and monoterpenes and is available under the trade name Norpine-65. Snowshoe hare, L. americanus, and voles,M. townsendii, consume less laboratory chow, apples, or carrots if they are treated with pine oil. This response did not habituate within the time of the experiment. When considering the use of pine oil as a herbivore repellent, we have to keep in mind that it is phytotoxic to seedlings if applied topically (Bell and Harestad, 1987). Red deer, C. 

Signal pollinator attractants geographic variation multiple pollinators conditioning stimulus (T floral constancy) synergist pollinator attractants conditioning stimulus (T floral constancy) anti-microbial agents herbivore repellent synergist... 

Noise biosynthetic by-products phylogenetic artifacts neutral genetic variation herbivore repellent anti-microbial agents environmental plasticity methodological artifact biosynthetic by-products phylogenetic artifacts neutral genetic variation environmental plasticity methodological artifact... 

The repellent a commercial herbivore repellent, a plant extract, or known aversive plant compounds. 

Any herbivore repellent can be tested. Good choices are commercially available deer or rabbit repellents. 

Alkaloids are compounds that contain nitrogen in a heterocyclic ring and are commonly found in about 15-20% of all vascular plants. Alkaloids are subclassified on the basis of the chemical type of their nitrogen-containing ring. They are formed as secondary metabolites from amino acids and usually present a bitter taste accompanied by toxicity that should help to repel insects and herbivores. Alkaloids are found in seeds, leaves, and roots of plants such as coffee beans, guarana seeds, cocoa beans, mate tea leaves, peppermint leaves, coca leaves, and many other plant sources. The most common alkaloids are caffeine, theophylline, nicotine, codeine, and indole... 

Allelopathic compounds act as repellents for herbivorous pests, so the same strategy used in weed control could be effective against pests and pathogens. Only allelopathy is not possible to use the complete control of weeds, pests or diseases it is necessary to combine it with other methods of plant protection. 

Sullivan, T. P., Nordstrom, L. O. and Sullivan, D. S. (1985) Use of predator odors as repellents to reduce feeding damage by herbivores. I. Snowshoe hares (Lepus americanus). J. Chem. Ecol. 11,903-919. 

Before delving into ways the living world uses its special chemicals, we should note that these compounds touch our own lives in important ways. For millennia, humans have been borrowing natural chemicals for their own purposes, most often as drugs. Our oldest medicine is opium, which we prepare from the opium poppy (Papaver somniferum) today much as Mediterranean peoples did four thousand years ago. Just as we do, these early communities valued opium for its ability to kill pain and impart a sense of well-being. The principal constituent responsible for these effects is a chemical compound called morphine, which remains unsurpassed in its ability to control severe pain. In poppies, morphine s toxicity and bitterness presumably repel herbivores looking for a tasty meal. 

Not surprisingly, much research in sharks, skates and rays has focused on the responses of sharks to human body odors. Human blood attracts sharks, while sweat does not, and urine was even slightly repellent (Tester, 1963). Practitioners use whale meat and mixtures of fish meal and fish oils as shark attrac-tants. In both carnivorous and herbivorous bony fish (Osteichthyes) smell deals with prey odors, social odors, and chemical stimuli in homing, and it is mediated by the first cranial nerve, the olfactory nerve. By contrast, taste serves in detection and selection of food and avoidance of toxic food, and it employs the facial, glossopharyngeal, vagal, and hypoglossal nerves. 

Control of rodent and other herbivore damage Area repellents Predator odors... 

The trans-chrysanthemic acid 88 is an essential component of naturally occurring pyrethrin esters which are present in the flower of Chrysanthenum cinera-riaefolium and has a defense function in these plants [122]. Very effective as an antifeedant for herbivores, it presents a broad spectrum as an insect repellent. 

Most insect herbivores appear to be rather effectively repelled by furanocoumarin-containing plants (21-24). A notable exception to this generalization occurs among some butterflies of the family Paplllonldae, whose caterpillars are adapted to feed successfully and in fact preferentially on plants that contain linear, but not angular, furanocoumarlns (22). These circumstances prompted us to undertake studies with the black swallowtail butterfly (Papilio polyxenes) and radiolabeled furanocoumarlns in attempts to elucidate the nature of the Insect/furanocoumarln Interactions Involved. 

In medieval times, cities commonly erected walls as a protective barrier to invasion. Plants have evolved similar protective mechanisms. Thorns and nettles which repel most herbivores are two examples of protective barriers. To ward off Insect attack, plants have evolved non-glandular trichomes which act in a similar fashion. Thus, in some plants, the density, length, or branching of trichomes have been negatively correlated with insect survival (10). 

Leaf cutter ants, abundant from Texas to Argentina are polyphagous herbivores, but will not attack several plants. The ant, Atta cephalotes, for example, does not feed on Lasianthaea fruticosa (Asteraceae). The active repellent substance has been demonstrated to be lasidiol angelate (8p. 

Many triterpenes also have anti herbivore activity. In general, those which are highly oxygenated seem to be more active in this regard M). The role of cardiac glycosides, insects and their predators has been reviewed (91-94). A number of metabolically altered triterpenes from the Rutaceae, Meliaceae and Simaroubaceae are antifeedants. Extracts of neem tree seeds (Azadirachta indica. Meliaceae) were shown to be repellent to a number of insects when applied to various crop plants at low concentrations. The probable active compound is tetranortriter-pene, azadirachtin (9 ). This compound from the leaves and fruits... 

Attraction or repellence of herbivores by induced plant odors... 

Bernasconi, M. L., Turlings, T. C. J., Ambrosetti, L., Bassetti, P. and Dorn, S. (1998). Herbivore-induced emissions of maize volatiles repel the corn leaf aphid, Rhopalosiphum maidis. Entomologia Experimentalis etApplicata 87 133-142. 

Plant terpenes may deter herbivores and attract pollinators. They may participate in competition among plants and may act as antibiotics, called phytoalexins, to protect plants from bacteria and fungi.84 In invertebrate animals terpenes serve as hormones, pheromones, and defensive repellants (Figs. 22-3,22-4). The terpene squalene is the precursor to sterols. Some terpenes are toxic. For example, thujone (Fig. 22-3), which is present in the liqueur absinthe, causes serious chronic poison-... 

Quinolizidine alkaloids are mainly found in plants of the Leguminosae/Fabaceae family. They deter or repel feeding of herbivores, and are toxic to them by a variety of mechanisms. A number of plants (Laburnum, Cytisus, Lupinus) containing significant quantities of these alkaloids must be regarded as potentially toxic to humans, and are known to be responsible for human poisoning. 

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