Conclusions

● When exposed to filter papers 3 mins after they had been impregnated with lavender essential oil, 66% - 90% poultry red mite mortality occurred within 24 hrs. This suggests that lavender essential oils may hold promise as acaricides for managing this pest.

● If impregnated filter papers were left for 24 hrs prior to use, mortality rates fell to 11% or less, suggesting that if used as acaricides, the residual toxicity of these products is likely to be short-lived

Plant essential oils have been investigated as control products for poultry red mite

Investigating the residual toxicity of lavender essential oils as acaricides against the poultry red mite (Dermanyssus gallinae)

Use of synthetic acaricides is hampered by issues of pest resistance & product withdrawals

Plant essential oils contain chemicals toxic to pests, such as linalool from lavender

More research is therefore needed to assess the potential of plant essential oils as acaricides

Essential oils may be highly volatile. Any acaricidal effect might therefore be short-lived

Poultry red mite, Dermanyssus gallinae

Callaghan, K. 1,2, George, D.R. 1, Guy, J.H. 1, Sparagano, O.A.E. 1. 1 School of Agriculture, Food & Rural Development, 2 School of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK (Olivier.sparagano@ncl.ac.uk)

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Filter paper left for 3 min prior to use

Filter paper left for 24 hr prior to use

Results

Figure 1. Mean percentage mortality rate of Dermanyssus gallinae, when exposed to filter papers 3 mins & 24 hrs after being impregnated with six different lavender essential oils. Stars represent significant differences in mite mortality between different treatments using the same oil, where *** = P < 0.001. Means & 95% confidence limits have been back-transformed from arcsin square root transformed data used in ANOVA. Lavender 1 = Lavandula angustifolia, origin Australia. Lavenders 2 and 3 = Lavandula angustifolia, origin France (different regions). Lavender 4 = Lavandula angustifolia, origin Croatia. Lavender 5 = Lavandula officinalis, origin France. Lavender 6 = Lavandula dentata, origin France.

Aim

● Lavender essential oils are toxic to poultry red mite (Dermanyssus gallinae) & may thus offer an alternative to synthetic acaricides for managing this pest.

● The aim of the current work was to investigate the residual toxicity of lavender essential oils to the poultry red mite to allow further comment on the potential of these products as acaricides.

Methods

● 25 poultry red mite were placed in Petri dishes with a filter paper impregnated with 0.21 mg/cm² of essential oil from one of the selected six types of lavender.

● These filter papers had been placed in a fume cupboard for either 3 mins or 24 hrs after impregnation. Eight replicates were done for each treatment.

● Mites were left in dishes at 22°C for 24 hours, after which they were checked for mortality.

● Mortality was corrected (to account for control mortality) & differences in percentage mortality between treatments was assessed for each lavender type (see Figure 1).

24 hr

Insecticide=amazon.com; toy mite=profesoraloca.vox.com; superman symbol=comicbookcloset.com; lavender=alphazero.web.aplus.net; essential oil=thebodyshop.com; Petri-dish=laboratory-supply.com; poultry red mite=georgiasouthern.edu.

Lavender

Acknowledgements; This work was partially funded by Defra (UK) via Newcastle University’s MITEeHEN Project