Comparison of learning in related generalist and specialist eucoilid parasitoids

Abstract

Effects of learning in two microhabitat specialists, Leptopilina boulardi Barbotin et al. and L. fimbriata Kieffer were compared to previous and new results of learning in the microhabitat generalist L. heterotoma Thomson. Females were given one or more oviposition experiences on hosts in different types of substrate. In all species oviposition experience affected the choice for a substrate, although this effect of learning was considerably less in L. fimbriata compared to the other two species. Patch times, known to be highly determined by experience in the generalist L. heterotoma, were much less flexible in the specialists. L. boulardi and L. fimbriata have fixed patch times on their natural substrate and have variable patch times on other substrates only. In all three species one oviposition affected the choice for a substrate. Additional ovipositions showed no different effect. An accumulative effect of the number of ovipositions on patch times was found in L. heterotoma only. Retention of the learning effect was only studied in L. boulardi, and was shown to be similar to that reported for L. heterotoma, i.e. two to three days. Although learning was found in both the generalist and the specialist species studied, it seems to affect their foraging behaviour differently.

An operating cost of learning in Drosophila melanogaster

“…The most widely accepted general idea is that learning allows an individual to adjust its behaviour in an adaptive way in a changing environment, where fitness consequences of a given behavioural action vary from generation to generation, or even within a lifetime (Johnston 1982;Papaj & Prokopy 1989;Stephens 1991). Evidence in support of this prediction is growing (Simons et al 1992;Prokopy et al 1993;Potting et al 1997;Geervliet et al 1998;Sol & Lefebvre 2000;Egas & Sabelis 2001;Jackson & Carter 2001;McNeely & Singer 2001;Mery & Kawecki 2002).…”

Natural variation in learning rate and memory dynamics in parasitoid wasps: opportunities for converging ecology and neuroscience

“…In the presence of its innately preferred substrate, the majority of the wasps still choose the innately preferred substrate, however. Only when testing these wasps on the learned substrate, it becomes clear that their response to this substrate has increased [32]. Thus, innate responses and learned responses should not be considered as two separate traits, but as two dynamically interacting components of insect behaviour.…”

“…For instance, if hosts can always be found on the same host plants throughout the year, the value of innate preferences is higher than under more variable conditions [1,24,43]. Indeed, both in parasitoids and in bumble-bees it was found that strong innate preferences are less likely to be changed after experience [15,32].…”

“…Some species of Leptopilina are generalist species that attack multiple drosophilid species in several habitats, whereas other species have a more restricted host and/or substrate range. Poolman Simons et al [32] compared the generalist Leptopilina heterotoma and the specialist Leptopilina boulardi parasitoids and showed that both species shifted their preference towards a learned odour after a single oviposition experience. Other studies have found that a preference shift was maintained up to 3 days in L. heterotoma [55] and approximately 1 -2 days in L. boulardi [32,56].…”

An acquired distaste: Sugar discrimination by the larval parasitoidMicroplitis croceipes(Hymenoptera: Braconidae) is affected by prior sugar exposure

“…This acquired feeding inhibition implies that in a patch containing superior sugars such as glucose, sucrose or fructose, parasitoids rapidly give up the lesser quality food in favor of foraging for the nutritionally superior sugars. Similarly, parasitoids effectively discriminate between hosts in and among patches containing different qualities of hosts, and they change host acceptance based on previous experience (Papaj and Vet, 1990;Poolman Simons et al, 1992;Geervliet et al, 1998;Duan and Messing, 1999;Fujiwara et al, 2000). Surprisingly, also in the case of fructose we see a pronounced reduction in feeding time following exposure to glucose or sucrose; this phenomenon was consistently observed in multiple experiments and with both colonies of M. croceipes.…”