Age-Related Changes in Foraging in the German-Cockroach (dictyoptera, Blattellidae)

WOS:A1991GC72700009International audienceThe dynamics of exploitation of standard experimental food sources by the German cockroach, Blattella germanica L. (Blattellidae), were analyzed in an urban habitat in relation to developmental stage. The data presented here stress differences in foraging capacities between small (first- and second-instar) larvae and animals of other developmental stages. The first animals to arrive in a food patch presented a developmental-stage distribution significantly different from that of the general population. Adults and large larvae (fifth and sixth instars) were the first to find food sources and, in particular, before small larvae. Significant differences appeared between developmental stages concerning giving-up time and the time animals left a patch. Small larvae were significantly under-represented in a patch just before food exhaustion but they were significantly more numerous than expected just after depletion. Small larvae remained in the vicinity of a depleted food dish longer than animals of other developmental stages. Adults left patches as soon as these were depleted, long before small larvae did. Developmental stage influenced rate of departure. These observations indicate that cockroaches improve their foraging performance as they grow larger