Conditioned taste aversion in the cricket Gryllus bimaculatus.

Conditioned taste aversion (CTA) is a form of classical conditioning in which animals associate the taste of a food with illness caused by toxin contained in the food. CTA in mammals is achieved with a long interval of up to several hours between food ingestion and illness induced by LiCl injection. Insects also exhibit CTA, but not much is known about its features. We investigated whether the cricket Gryllus bimaculatus exhibits CTA when ingestion of a sugar solution is followed by LiCl injection. Crickets that ingested sucrose solution 5-10 min before LiCl injection exhibited reduction of sucrose consumption tested 24 or 48 h after injection compared to that tested 24 h before injection. In contrast, crickets that ingested sucrose solution 5-10 min after LiCl injection or 1 h or 8 h before or after injection did not exhibit reduction of sucrose consumption, indicating that reduction of sucrose consumption by CTA training is pairing-specific. We conclude that CTA in crickets is similar to that in mammals in that one-trial pairing is sufficient to achieve memory retention for days, but it differs in that it is achieved with a relatively short interval (< 1 h) between food ingestion and toxin injection.