Testing and comparing the effectiveness of different leech repellents.

Abstract

We studied the difference in effectiveness among different leech repellents, including eucalyptus oil, insect repellent with DEET, household vinegar, and tobacco leaves. Specifically, we analyzed the differences in percentage of individual Erpobdella ocura attachment and the time distribution of attachments. We recorded the number of attachments to a food source covered in a deterrent and categorized attachments by three equal time intervals for 30 minutes. There was a significant difference in percent attachment between the control and three of the deterrents: eucalyptus oil, tobacco leaves, and insect repellent with DEET (p<0.0001). There was no significant difference in deterrence among these three effective treatments. There was a difference in time distribution of attachments among ineffective and effective treatments. These results show a significant difference in the effectiveness of E. obscura deterrence of suggested repellents. The knowledge obtained from these results could be used to draw conclusions on the mechanisms this species uses to hunt prey and could be useful for future ecological studies.