Keeping leeches at bay: Field evaluation of plant-derived extracts against terrestrial blood-sucking leeches (Haemadipsidae) in Lao PDR

► Leeches are common in the damp forests of the Indo-Pacific region. ► Traditional use of plant-derived repellents have been used by Lao ethnic groups for generations. ► Leech repellent activities of aqueous extracts of Sapindus rarak DC., Catunaregam spathulifolia Tirv. and Vernonia elaeagnifolia DC. were evaluated. ► All exhibited high leech repellent activity, C. spathulifolia (62.6%), V. elaeagnifolia (63.0%), and S. rarak (82.6%). ► S. rarak is both highly effective, and commonly available at limited or no cost.