In vitro Evaluation of Acaricidal Efficacy of Selected Essential Oils against Dermanyssus gallinae

Abstract

Intensification of poultry production has been associated with an increase in parasite prevalence and adaptation of an invasive external parasitic species, such as the poultry red mite (Dermanyssus gallinae). The studies of biological efficacy (contact and fumigant) and level of toxicity to mites indicated that the external application of essential oils (EOs) can be an alternative to acaricides. In this study, the results of acaricidal efficacy of eight selected EOs - Lavandula angustifolia Mill., Laurus nobilus L., Mentha x piperita L., Mentha spicata L., Ocimum basilicum L., Salvia officinalis L., Satureja montana L. and Thymus vulgaris L. are presented. Their chemical profiles were analyzed by gas chromatography coupled with mass spectrometry (GC–MS). The acaricidal efficacy of EOs (6% concentration) was tested on adult mites over 10 days in laboratory conditions using the Petri-dish method, through direct exposure for 1 min (contact toxicity) and subsequent exposure for 1 h (residual toxicity). The most effective EO in direct exposure-contact, after 48 h of observation, was S. montana (100% toxicity), while the greatest residual effect was observed in T. vulgaris (11% toxicity). The obtained results showed high efficacy of the EOs against the mites through direct contact and thus their great acaricidal potential. However, the activity was lost with subsequent exposure, indicating the absence of prolonged effect. Possible ways to overcome this problem are discussed further in this paper. In any case, the present study confirmed the acaricidal potential of herbal medicines that can be used in the integrated control of poultry red mite.