Azima Laili Hanafiah, Ho Tze Ming, Vishalani Vishnu Narainasamy and Ahmad Taufik Yusoff (2012). Laboratory evaluation of six crude plant extracts as repellents against larval Leptotrombidium deliensi (Acari: Trombiculidae). Asian Pacific Journal of Tropical Biomedicine Supplement 1: 257-259
Objective: To examine the repellency of crude plant extracts of onion (Allium cepa var. aggregatum (A. cepa)), garlic (Allium sativum (A. sativum)), clove (Syzygium aromaticum (S. aromaticum)), cinnamon (Cinnamomum zeylanicum (C. zeylanicum)), ginger (Zingiber officinale (Z. officinale)) and pandanus (Pandanus amaryllifolious (P. amaryllifolious)) on larval Leptotrombidium deliense (L. deliense).
Methods: The repellency assay used is a modification of the technique developed by Azima. Extracts at different concentrations (10%, 5%, 2.5%, 1%, 0.1%, and 0.01%) were evaluated.
Results: All extracts except that from ginger had similar repellencies ranging between 80%-96% at 10% concentration. At the lowest concentration (0.01%), onion extract gave the highest repellency (30%) followed by clove and cinnamon (23%).
Conclusion: Generally, the plant extracts showed various degrees of repellency against the larval mites and the repellency increased with increasing concentrations of the extracts.