Feeding habits metabolism

The nutritional requirements of insect species exhibiting different feeding habits like scavengers, parasites, predators and phytophagous insects, are similar in a qualitative sense (O. Each insect species needs, however, a particular quantitative composition of nutrients in its diet to complete development ( ). The presence of toxic substances in plants, secondary plant substances as they were formerly called by phytochemists, forms a barrier which phytophagous insects have overcome by specialization. Thus, an insect can tolerate or detoxify the secondary plant substances present in its host plants, while the majority of these substances being present in other plants still acts as toxins (J ). In this way phytophagous insects are adapted to the metabolic qualities of their host plants, i.e. a particular chemical composition of nutrients and secondary plant substances. 

Diet provides the major pathway for lead exposure, and amounts in bone are indicative of estimated lead exposure and metabolism. Amounts of whole body lead and feeding habits of roadside rodents were correlated body burdens were highest in insectivores such as shrews intermediate in herbivores, and lowest in granivores. Food chain biomagnification of lead, although uncommon in terrestrial communities, may be important for carnivorous marine mammals, such as the California sea lion accumulations were highest in hard tissues, such as bone and teeth, and lowest in soft tissues, such as fat and muscle. A similar pattern was observed in the harbor seal. 

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