Memory duration is positively correlated with host fruit preference and offspring performance in a polyphagous frugivore

Abstract

AbstractUnderstanding how polyphagous herbivores optimise foraging for multiple hosts remains unclear: prior experiences with hosts and the modification of subsequent behaviours (referred to in the broad sense as learning) have been proposed as one potential mechanism. A critical feature of learning is the effect of reward value, with learning and memory positively linked with reward quality. However, the links between host plant quality for offspring, prior experience and memory have not been researched in herbivorous insects. No‐choice and dual‐choice olfactometer assays were conducted to determine how prior oviposition experience on nine different fruits affected host preference, response times and the duration of altered response times (over subsequent days) in the polyphagous frugivore, Bactrocera tryoni (Froggatt). In no‐choice tests, the average time naïve B. tryoni took to respond to the different fruit odours differed and was directly correlated to larval host quality; for example, naïve females responded fastest to guava, a high‐quality larval host, and slowest to blueberry, a poor host. However, B. tryoni experienced on fruits for 24 h responded significantly faster to all fruits equally, regardless of fruit type. The duration of the experience‐based responses was directly correlated with fruit quality, with females displaying the longest response retention when experienced on high‐quality fruits and the shortest on low‐quality fruits. For B. tryoni, we demonstrate that the host responses following prior experience are influenced by the quality of a host plant for offspring survival.