Why does wormwood repel fleas? - briefly
Wormwood contains thujone, sesquiterpene lactones, and other bitter essential oils that disrupt flea nervous function and cause irritation, leading the insects to avoid treated areas. Its potent odor also masks host scents, further deterring fleas.
Why does wormwood repel fleas? - in detail
Wormwood (Artemisia absinthium) contains a complex mixture of volatile oils and bitter sesquiterpene lactones that act on fleas through several biochemical pathways.
The primary repellent agents are thujone, camphor, and 1,8‑cineole. Thujone interferes with the insect nervous system by binding to γ‑aminobutyric acid (GABA) receptors, causing hyperexcitation and loss of coordination. Camphor and 1,8‑cineole act as strong olfactory disruptors; fleas rely on scent cues to locate hosts, and these compounds mask or overwhelm those cues, reducing host‑finding efficiency.
In addition to neurotoxic effects, the bitter lactones provoke feeding deterrence. When a flea contacts treated surfaces, the lactones bind to gustatory receptors, producing an aversive taste that discourages further movement.
Environmental factors enhance efficacy. The volatile nature of the oils ensures rapid dispersion in the air, creating a protective plume around treated animals or bedding. Persistence is limited by evaporation, so repeated application maintains a concentration above the behavioral threshold for flea avoidance.
Practical considerations for use include:
- Dilution of essential oil in a carrier (e.g., water or oil) at 0.5–2 % concentration for topical sprays.
- Application to fur, bedding, or surrounding area, allowing evaporation before contact with the animal.
- Monitoring for skin irritation; some individuals may react to thujone at high doses.
Overall, wormwood repels fleas by combining neurotoxic, olfactory, and gustatory mechanisms, with volatile compounds delivering a short‑term barrier that deters host‑seeking behavior.