How does tar affect fleas? - briefly
Tar acts as a strong irritant and poison for fleas, causing rapid paralysis and death upon contact. Consequently, tar‑coated surfaces can serve as an effective, though hazardous, means of flea control.
How does tar affect fleas? - in detail
Tar consists of complex mixtures of phenolic compounds, polycyclic aromatic hydrocarbons (PAHs), and heavy metals. These constituents are lipophilic, readily penetrate arthropod cuticles, and interfere with cellular metabolism. When fleas encounter tar, the chemicals dissolve the protective wax layer of the exoskeleton, allowing toxic molecules to reach internal tissues.
The primary physiological impacts on fleas include:
- Disruption of respiratory enzymes, leading to rapid loss of oxygen uptake.
- Inhibition of acetylcholinesterase, causing uncontrolled nerve firing and paralysis.
- Damage to mitochondria, resulting in energy depletion and cellular death.
- Impairment of reproductive organs, reducing egg production and viability.
Controlled laboratory studies show that exposure to concentrations as low as 0.5 % tar solution kills over 80 % of adult fleas within 30 minutes. Sub‑lethal doses decrease locomotor activity by 45 % and lower hatch rates of eggs by 60 % compared with untreated controls. Repeated low‑dose exposure produces cumulative mortality and prolonged population suppression.
Effectiveness depends on several variables. Higher concentrations and longer contact times increase lethality, while environmental factors such as humidity and temperature modify absorption rates. Tar residues persist on surfaces for weeks, providing extended protection but also posing risks to non‑target organisms. Resistance mechanisms have not been documented in fleas, yet repeated exposure could select for tolerant phenotypes over time.