Autotoxicity and its prevention

There is some evidence that the monarch butterfly suffers physiological cost as a result of sequestering cardiac glycosides. For example melanic larvae, in addition to other aberrations have been observed in the monarch (L. Brower et al., 1972 L. Brower and Glazier, 1975 Seiberetc/., 1980). Dixon etc/. (1978) 

There may be an unexpected side benefit arising from possession of toxins in the body. D. Smith (1978a) has found that larvae of Danaus chrysippus, an African relative of the monarch, are less susceptible to attack by endoparasitic Diptera if they have fed on cardiac glycoside-containing plants. 

The ultimate in avoiding autotoxicity is for the wamingly colored prey to forego a toxin altogether. This seems to contradict what was said earlier about toxins vj. distastefulness. Indeed, we should probably not find it common, but Gibson (1980) has shown that birds can be taught to avoid models when the only stimulus is complete frustration, i.e., the models escape . This concept may be applicable to certain brightly colored leafhoppers, but it has received little attention. 

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