The regulation of feeding: locusts and blowflies are not so different from mammals.
The regulation of feeding in two insect groups, the locusts and the blowflies, is reviewed. The patterning of feeding is discussed first, and then the underlying mechanisms are considered in detail. The concept of "central excitability" is the key to understanding the controls of feeding. It represents a central nervous mechanism for tuning the sensitivity of the insect to food-related stimuli. The level of central excitation is influenced positively by food and also non-food stimuli, both from within and outside the animal, and negatively by deterrent stimuli and by feedbacks from peripheral systems such as stretch receptors on the gut wall, hormones and blood composition. Sustained gustatory input is required if feeding is to continue, once initiated. The level of central excitation present as a meal begins influences ingestion rate and the amounts of negative feedback tolerated before feeding stops. The duration of intervals between meals is then a function of a number of excitatory stimuli and of feeding-induced changes which reduce the likelihood of further feeding, e.g., hormone release, changes in nutrient composition or osmotic pressure of the blood, and gut distension. Other areas reviewed include changes in the regulation of feeding during the life history and the control of drinking.
D000818:Animals; D001069:Appetite Regulation; D002490:Central Nervous System / Q000378:metabolism / Q000502:physiology; D002940:Circadian Rhythm; D004063:Digestion; D004175:Diptera / Q000378:metabolism / Q000502:physiology*; D004327:Drinking Behavior / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D006110:Grasshoppers / Q000378:metabolism / Q000502:physiology*; D007408:Intestinal Absorption; D010507:Periodicity