Alternative methods to separate preingestive and postingestive effects

Alternative Methods to Separate Preingestive and Postingestive Effects 

In addition to separate analyses of consumption and growth efficiency, several other techniques have been used to quantify the relative importance of semiochem-icals on feeding behavior and postingestive physiology with varying levels of success. Some of these methods are summarized below. Because many of these methods are quite invasive and manipulative (i.e., direct injection of semio-chemicals, removal of taste receptors), they may alter the behavior or physiology of subjects substantially in their own right. 

This method has been used several times to identify deleterious effects that do not result in acute toxicity (e.g., Berenbaum Feeny 1981 Rauscher 1981  

Miller Feeny 1983 Usher Feeny 1983). The fact that the application of the method utilizes standard ratio-based variables for relative consumption rate and relative growth rate, however, introduces the problems of the use of ratios, as described earlier. 

After the microcapsules are made, they can be administered to subjects after incorporation into an artificial diet. Alternatively, the subjects can ingest the microcapsules after the microcapsules have been spread on the surface of an acceptable substrate for ingestion by normal feeding (Usher et al. 1989). After ingestion, the capsules break down, releasing the chemical, and the effect of the chemical on aspects of performance (Table 5.2) can be measured as for most other postingestive bioassays. 

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Alternative methods to separate preingestive and postingestive effects 257... 

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