VARIETY IS THE SPICE OF LIFE - FREQUENT SWITCHING BETWEEN FOODS IN THE POLYPHAGOUS GRASSHOPPER TAENIOPODA-EQUES BURMEISTER (ORTHOPTERA, ACRIDIDAE)

Successive feeds taken by the polyphagous grasshopper Taeniopoda eques generally declined when food remained the same but increased as different food became available. This led to repeated switching between food items. In the field, the switching rate was highest when feeding bouts were very short, but when feeding bouts lasted a minute or more, the switching rate stabilized at about one switch every three feeding bouts. In the laboratory, the pattern of declining feeding-bout length on one item, foolowed by an increase on a novel food was demonstrated with very acceptable food plants, and even with nutritionally balanced and identical artificial diets, differing only with respect to flavour. When the chemicals imparting the flavours were either injected into the haemolymph, or given as an oral dose in semi-micro-gelatin capsules, no effects on acceptability of the flavoured diets were observed. This highly polyphagous insect species demonstrated a predilection for novel flavours or variety, suggesting that several descriptors of processes associated with changing acceptability of food in other animals may have a common mechanism. © 1992 The Association for the Study of Animal Behaviour.