# Efficacy of citronella and ginger essential oil combinations against chicken lice (Menopon gallinae) and mites (Ornithonyssus bursa): Chemical characterization, contact toxicity, and in vivo validation

## TL;DR

Citronella and ginger essential oil blends effectively kill chicken lice and mites, offering a safe, natural alternative to harmful pesticides.

## Contribution

The study introduces a novel plant-based pesticide using citronella and ginger oil combinations with proven efficacy against poultry ectoparasites.

## Key findings

- Citronella and ginger essential oil combinations achieved 100% in vitro mortality of lice and mites within 24 hours.
- The CT30:G70 blend significantly reduced mite infestation (40.97%) in vivo with no adverse effects on chickens.
- The CT70:G30 formulation showed the greatest lice reduction (22.67%) by day 14 in naturally infested chickens.

## Abstract

Ectoparasites, such as Menopon gallinae (chicken lice) and Ornithonyssus bursa (chicken mites), have a significant impact on poultry health and productivity, resulting in substantial economic losses and potential zoonotic risks. Conventional synthetic pesticides, though effective, pose health and environmental concerns. Hence, plant-based alternatives such as essential oils are gaining attention for their insecticidal properties. This study aimed to characterize the physical and chemical properties of citronella (Cymbopogon nardus) and ginger (Zingiber officinale) essential oils and to evaluate their acaricidal and insecticidal efficacy, both in vitro and in vivo, against M. gallinae and O. bursa.

Essential oils were extracted through steam distillation and characterized using specific gravity, refractive index, and optical rotation. Gas chromatography-mass spectrometry (GC-MS) was used to identify major chemical constituents. Contact toxicity assays were conducted on adult lice and mites exposed to essential oil combinations (Citronella [CT]: Ginger [G] in ratios of 70:30, 50:50, and 30:70). In vivo trials were performed on naturally infested chickens and mite-contaminated nests, with efficacy assessed at days 1, 7, and 14 post-treatment. Statistical analyses employed general linear mixed models and Tukey’s post hoc tests.

GC-MS revealed citral, neral, and limonene as key constituents of citronella oil, and zingiberene and sesquiphellandrene in ginger oil. All essential oil combinations showed 100% in vitro mortality of lice and mites by 24 h. In vivo, the CT70:G30 formulation achieved the greatest reduction in lice incidence by day 14 (22.67%), followed by trichlorfon (31.33%). For mites, trichlorfon exhibited the highest efficacy (3.33% incidence on day 14), while CT30:G70 also showed notable reduction (40.97%) with no adverse effects observed in treated birds.

Combinations of citronella and ginger essential oils, particularly CT30:G70, offer a promising natural alternative to chemical pesticides for managing poultry ectoparasites. Their high efficacy, rapid action, and safety profile support their use in organic and sustainable poultry farming.