Galling insect communities mediate the effects of fire on their associated parasitoid communities

KUZMANICH, N.; GIORGIS, M. A.; BERNASCHINI, L.; TAVELLA, J.; SALVO, A.

INSECT CONSERVATION AND DIVERSITY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 2023

1752-458X

1. Understanding fire effects on multitrophic levels is critical to the context of changesin fire regime and climate. Insects located at higher trophic levels, like parasitoids,are more vulnerable to habitat changes than insect herbivores because they needwell-established populations of their hosts to survive. Currently, fire effects on parasitoids and their interactions with their hosts are unknown.2. Our aim was to study the changes in abundance, richness and species composition,as well as the food web structure in a system involving parasitoids and gallinginsects under different fire scenarios. We asked whether potential changes in abundance, species richness and composition of parasitoid communities are explainedby galled plant abundance, species richness and composition of galling insects, andhow fire affects the structure of galling insect–parasitoid food webs.3. The highest parasitoid richness was found in the 9 years after fire scenario, whereasparasitoid abundance was not affected by fire. The parasitoid species compositionin the 9 years after fire scenario was different from that in the unburned and3 years after fire scenarios. Parasitoid communities were modulated by galled plantabundance, species richness and composition of galling insect communities. Vulnerability was significantly higher in 9 years after fire scenarios, but it increased withincreasing network size.4. Fire affects the community of parasitoids through changes in their host communities.Differences in exclusivity to fire scenarios and diet specialisation of parasitoid speciesand galling insect richness may explain the patterns found. Our study supports evidence that fire creates habitats heterogeneous in the availability of hosts shaping theparasitoid communities, with a bottom-up effect in food webs. Additionally, in burnedareas were recorded unique galling insect–parasitoid interactions.