Feeding repellent

Feeding repellents for pest birds are the most important application of chemical stimuli to manipulate bird behavior. Methyl anthranilate (Fig. 13.1) and dimethyl anthranilate, esters of benzoic acid, are found in concord grapes and are used as artificial flavorings. Starlings, Sturnus vulgaris, have an aversion to methyl anthranilate, which irritates the trigeminal nerve, and they feed less on food flavored with a variety of anthranilates. They avoid the more volatile anthranilates most. The odor is partly responsible for the effect contact is not necessary. In one particular experiment, only volatile compounds were aversive (Mason and Clark, 1987). If only anthranilate-treated food is offered, the birds will accept more of the flavored food than they do if they offered a choice between... 

Harada, K. (1989). Role of carboxylic group on feeding repellence of acidic amino acids and organic acids for oriental weatherfish. BulletinoftheJapaneseSocietyofScientijicFish-eries 55,927. 

Plant toxins have been known for many centuries. Rotenoids (rotenone), alkaloids (nicotine, coniine, strychnine), terpenoids (ovabin and hymenovin) are among the classes of natural products which provide numerous toxins (3-12). Toxins in plants often have the role of feeding repellents. They appear to be synthesized by plants as a defense against insects and other animals. 

Sour Grapes Methyl Anthranilate as Feeding Repellent for Birds... 

This real-world exercise tests the efficacy of a feeding repellent in free-ranging mammals. It constitutes the counterpart to the repellent effect of methyl anthranilate on feeding by birds (see Chap. 3). The experiment works at any place with wild squirrels and in any season. The many mammal repellents on the market are aimed against deer, predators such as raccoons, foxes and coyotes, and rodents such as voles, mice, squirrels, woodchucks, and others. Mammal repellents are known under names such as copper naphthenate, trimethacarb, zinc naphthenate, and ziram. 

In barley (Hordeum vulgare, Poaceae), phenylalanine is converted to tyrosine and then to tyramine. Tyramine (1) is subsequently methylated and converted to hordenine (7) (Fig. 28.13). A related species, Hordeum distichum, converts labeled phenylalanine into A(-methyltyramine (31), a reaction that is believed to procede via the intermediacy of the so-called NIH shift (32) (Fig. 28.13). The half-life of hordenine in barley is about 42 h (Waller and Nowacki, 1978). Hordenine has been suggested to play a role in allelopathy in cultivated barley fields and is a feeding repellent for grasshoppers (Smith, 1977b). 

Steroid alkaloids are poisonous to animals. Demissine, a demissidine glycoside, occurring in the green parts of the potato plant, acts, for instance as feeding repellent for the Colorado beetle Leptinotarsa decemlineata (E 5.5.3). Solasodine is an important raw material in the production of steroid hormones (F 4). 

Juglone is involved in the allelopathic interactions between higher plants (E 5.3) and is a feeding repellent for insects (E 5.5.3). 

The biological importance of these substances is not really elucidated. They are discussed to reveal antimicrobial or antiviral activity [51], and some of them are astringent and slightly bitter [50]. They may act as feed repellents, but they act also as antioxidants. 

A. Structure-Effect Relations between Calystegines and Glycosidases Mechanism of Inhibition Toxicology of Calystegines Possible Medicinal Applications Activity of Calystegines in Plants A. Plant Rhizosphere Allelopathic Activity Insect Feeding Repellent Activity Anti-Nematode Activity Plant-Fungi Interactions... 

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