Chemical Ecology of Black Widow Spiders

• Applicant: Andreas Fischer, Ph.D.
• Subject Area: Sensory and Behavioural Biology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 568156178

Chemical communication is the only modality shared by all animals. Yet, chemical signals are inconspicuous to us researchers and remain less investigated than readily observable communication modalities. Pheromones mediate fundamental behaviors between- and within sexes of a species, including mating, competition among females, and competition among males. To advance our understanding of chemical communication, this project will comprehensively explore the pheromonal signals of a widow spider. These sexually cannibalistic spiders are particularly intriguing to study pheromones between and within the sexes. Specifically, Latrodectus tredecimguttatus (European Black Widow spider) females utilize pheromones to attract males and elicit their courtship. Males respond to females with putative pheromone that increases their chances for copulation and survival. Simultaneously, males deter competing males from courted upon webs and females upon mating, presumably with pheromonal marks. Observed female clustering in natural habitats suggests a role for female-produced conspecific pheromones in habitat selection of females. We hypothesize: i. Female sex pheromone production coincides with female fecundity. (Female to male signal) ii. Male courtship silk contains aphrodisiac and appeasing pheromone (Male to female signal) iii. Males manipulate the attractiveness of females and their webs. (Male to male signal) iv. Female sex pheromone guides habitat selection of females. (Female to female signal) Employing state-of-the-art non-targeted metabolomics, coupled with multiple chemo-analytical techniques (LC-MS/MS, GC/MS, NMR), and diverse behavioral assays, we will characterize the putative pheromones and their functions. This proposal is based on previous studies, our own preliminary data and our demonstrated ability to characterize pheromones. This project will provide nuanced and comprehensive insights into how pheromones mediate mate choice, competition, and sexual conflict.

• DFG Programme: Research Grants