Personalities are not specific to humans but occur as well in non-human animals, ranging from
primates over rodents, birds, fishes to flies and spiders. Animals are said to possess personalities
if they consistently display certain behavioral traits in ways that consistently differ among
individuals within a given population across times and/or contexts. Animal personalities are well
documented in vertebrates, whereas comparatively little is known about personalities in
arthropods, the vast majority of animals. This proposal links animal personality formation in six
species of plant-inhabiting predatory mites to individual specialization in social niche and diet use,
as affected by early life experiences and parental effects. The hypothesis of individual niche
specialization postulates that individuals occupy different portions of the total niche of their
population to reduce inter-individual within-population competition. Animal personalities and
individual niche specialization have been traditionally viewed in isolation but may be causally
linked. This proposal pursues three intertwined hypotheses: (i) parental effects and early life
experiences shape personalities of predatory mites via experience- and state-dependent feedback
loops; (ii) parental effects and early life experiences shape individual specializations in diet and
social niche use, which co-vary with their personality traits; (iii) the predatory mites potential to
form personalities by parental effects and early life experiences is linked to species-specific
adaptations in social life style and diet specialization. Study animals are six species of predatory
mites ranging from group-living narrow diet specialists to mostly solitary living broad diet
generalists. All six species are important natural enemies of herbivorous mites and insects and
also used in biological control. Manipulative experiments, direct observations and visual and/or
automated analyses of video-taped behaviors are used to identify and characterize (i) the mites
specialization in diet and social niche use, and (ii) their behavioral tendencies in the five canonical
categories of animal personalities, i.e. activity, exploration, aggressiveness, shy/boldness and
sociability, as affected by diet, predation risk and social conditions during the parental generation
and early life of the experimental animals. This proposal breaks new ground by linking individual
niche specialization to animal personalities in mites, as shaped by two non-genetic pathways,
parental effects and early life experiences. Most innovative and original is assessment of both
maternal and paternal effects. Due to the study animals being important players in natural and
biological pest control, the outcome may also pave the way for development of novel pest control
strategies.