Repellent effect of selected essential oils against the wolf spider Pardosa hortensis (Araneae: Lycosidae)

Abstract

Spiders play a vital role in ecosystem balance, contributing to insect population control and biodiversity maintenance. However, their presence can cause fear and anxiety in humans, particularly those affected with arachnophobia. As spiders increasingly appear in human environments due to global climatic changes, even non synanthropic species, there is a growing need for effective and natural repellents - not only to reduce human discomfort but also to protect spiders by encouraging them to avoid urban areas and reducing unnecessary fatalities. In this study, we investigated the potential repellent properties of ten essential oils against female wolf spiders Pardosa hortensis (Araneae: Lycosidae), a very common grass species from the second-largest spider genus in the world that may occasionally venture into human surroundings. Through chemical analysis and binary choice behavioral tests, we identified five oils - catnip, cedarwood, cinnamon, citronella, and clove - that significantly deterred spider activity. Chemical constituents such as eugenol, β-caryophyllene, and geraniol likely contribute to these repellent effects. While further research is needed to validate these findings across diverse spider species, our study highlights the potential of essential oils and essential oil yielding plants as natural spider repellents, either at the entrances of houses or as natural garden defenses with specific plants. Altogether, it gives promise for arachnid management strategies and for mitigating conflicts between humans and spiders.