Deterring ticks with citrus and millipedes

Mar 11, 2013 by Sandra Avant
Deterring ticks with citrus and millipedes
In a lab test, this lone star tick nymph (Amblyomma americanum) was exposed to a citrus rind chemical, placed upside down inside an untreated filter paper cylinder, and observed to see whether it could right itself. Credit: Stephen Ausmus

Why do birds, monkeys and other animals rub themselves with citrus and creatures like millipedes? One likely reason is because certain plants and arthropods contain natural repellents.

Scientists with the U.S. Department of Agriculture (USDA) and the Smithsonian Conservation Biology Institute (SCBI) at the National Zoological Park in Front Royal, Va., examined compounds and for effectiveness against ticks. John Carroll, an entomologist with the Agricultural Research Service (ARS) at the Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md., and SCBI researcher Paul Weldon tested the responses of ticks to more than 20 different compounds in citrus extracts. ARS is the chief intramural scientific research agency of USDA.

Ticks were allowed to climb on vertical containing lemon rind exudates and other citrus chemicals. Repellency evaluation was based on whether ticks crawled into treated areas, continued to move, turned around, crawled back down or fell. Experiments also involved putting ticks inside treated filter-paper packets. After one hour, the ticks were removed, placed on their backs and timed to see if and when they could right themselves and climb out of a low enclosure and onto a fingertip.

Carroll, who works in BARC's Invasive Insect and Behavior Laboratory, found that some ticks were unable to crawl out of enclosures or even right themselves. Of 24 ticks exposed to one citrus chemical, only one righted itself. Of the chemicals tested, one killed or disabled ticks exposed to it for an hour. Several other chemicals kept ticks from climbing onto a fingertip.

To get to the bottom of why some animals anoint themselves with crushed millipedes, scientists used similar techniques to test ticks' responses to three benzoquinone chemicals found in millipedes. One benzoquinone killed ticks, one repelled them and all three benzoquinones hampered efforts of ticks to right themselves and climb. Higher concentrations of these chemicals were able to impair ' ability to climb for several months.

Explore further: Research challenges understanding of biodiversity crisis

More information: Read more about this research in the March 2013 issue of Agricultural Research magazine.

add to favorites email to friend print save as pdf

Related Stories

Getting rid of cattle fever ticks

Nov 02, 2010

Scientists at the U.S. Department of Agriculture (USDA) have developed two strategies to ward off cattle fever ticks that are crossing the border from Mexico into the United States. These ticks transmit bovine babesiosis, ...

Counting the cost of pesticide resistance

Sep 15, 2008

(PhysOrg.com) -- Researchers from the Beef CRC have developed a new test which could help producers minimise acaricide resistance in cattle ticks (Rhipicephalus (Boophilus) microplus).

A natural, alternative insect repellent to DEET

Feb 05, 2009

Isolongifolenone, a natural compound found in the Tauroniro tree (Humiria balsamifera) of South America, has been found to effectively deter biting of mosquitoes and to repel ticks, both of which are known spreaders of diseases ...

Recommended for you

Plants with dormant seeds give rise to more species

Apr 18, 2014

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Scientists tether lionfish to Cayman reefs

Apr 18, 2014

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

User comments : 0

More news stories

Meth mouth menace

Something was up in Idaho. While visiting a friend in Athol, a small town north of Coeur d'Alene, Jennifer Towers, director of research affairs at the Tufts University School of Dental Medicine, noticed ...