Insect Repellent Band

ARS chemist Aijun Zhang has discovered that a compound from pine oil is a natural repellent for mosquitoes and ticks. Photos courtesy of Aijun Zhang, ARS.

Tick and Mosquito Repellent Can Be Made Commercially from Pine Oil

By Sharon Durham
June 23, 2008A naturally-occurring compound prepared from pine oil that seems to deter mosquito biting and repels two kinds of ticks has been found by Agricultural Research Service (ARS) scientists.

A patent (US 7,378,557 B1) was issued on May 27 for the compound, isolongifolenone, and partners are being sought to bring this technology to commercial production.

In laboratory tests, ARS chemist Aijun Zhang in theInvasive Insect Biocontrol and Behavior Laboratory, Beltsville, Md., and his colleagues discovered that the naturally occurring compound deters the biting of mosquitoes more effectively than the widely used synthetic chemical repellent DEET. The compound also repelled two kinds of ticks as effectively as DEET.

Insect repellents are used widely to prevent bites from mosquitoes, sand flies, ticks and other arthropods. For the most part, people apply repellents just to avoid discomfort, but there is a more serious side to the use of these products. Human diseases caused by blood-feeding ticks and mosquitoes represent a serious threat to public health worldwide.

Malaria is the chief threat, killing approximately two million people per year and threatening billions. Other diseases include dengue fever, chikungunya, Lyme disease and typhus. Some segments of the public perceive efficient synthetic active ingredients as somehow more dangerous than botanical compounds, giving additional importance to the discovery of plant-based isolongifolenone.

Zhang’s team also developed an easy and efficient method to prepare this repellent. Many natural-product chemicals isolated from plants and essential oils have proven to have repellent effects. Most often, such compounds never attain commercial development and their use is limited or impractical because they are expensive and not available in pure and large quantities.

In contrast, this newly-discovered repellent can be prepared inexpensively from pine oil feedstock in ton quantities for large-scale commercial applications, giving it a significant advantage over many of the other natural-product repellent chemicals.

ARS is a scientific research agency of the U.S. Department of Agriculture.

West Nile Virus

What Is West Nile Virus, and what does it mean to consumers?
West Nile virus (WNV) is a potentially serious illness. Experts believe WNV is a seasonal epidemic in North America that flares up in the summer and continues into the fall. 1 in 150 people suffer from severe illness when they contract WNV, which includes the following symptoms: high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent. Up to 20% of the people who become infected have symptoms such as fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. These can last several weeks. 80% of people can contract WNV and not even know they have it, although the virus will reside in the body for lengthy periods of time.

“The easiest and best way to avoid WNV is to prevent mosquito bites.” -Centre for the Division of Vector-Borne Infectious Diseases.

Most often, WNV is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread WNV to humans and other animals when they bite.

People over 50 at higher risk to get severe illness. People over the age of 50 are more likely to develop serious symptoms of WNV if they do get sick and should take special care to avoid mosquito bites.

Being outside means you’re at risk. The more time you’re outdoors, the more time you could be bitten by an infected mosquito. Pay attention to avoiding mosquito bites if you spend a lot of time outside, either working or playing.

There is no cure for WNV – symptoms will either pass on their own, or those with severe cases may suffer death.

Eastern Equine Encephalitis Virus (EEEV)

Eastern equine encephalitis (EEE) is a mosquito-borne viral disease. EEE virus (EEEV) occurs in the eastern half of the United States where it causes disease in humans, horses, and some bird species. Because of the high mortality rate, EEE is regarded as one of the most serious mosquito-borne diseases in the United States right now.

EEEV is transmitted to humans through the bite of an infected mosquito. It generally takes from 3 to 10 days to develop symptoms of EEE after being bitten by an infected mosquito.

Many persons infected with EEEV have no apparent illness. In those persons who do develop illness, symptoms range from mild flu-like illness to inflammation of the brain, coma and death. The mortality rate from EEE is approximately one-third, making it one of the most deadly mosquito-borne diseases in the United States. There is no specific treatment for EEE; optimal medical care includes hospitalization and supportive care.

Current cases of EEE in the United States have pushed EEE into the league of concern for which WNV was previously dominant. Mosquito bite prevention has become one of the leading concerns in health care in North America.