'Natural' alternative to DEET insect repellent

I happened to come across this article about a potential alternative to DEET that is found in the South American Tauroniro tree (Humiria balsamifera). The compound, which is called "(-)-isolongifolenone," can be synthesized from cheap turpentine oil feedstock, and researchers from the U.S. Department of Agriculture have also patented a more cost effective method to produce isolongifolenone analogs. The researchers found that isolongifolenone worked better than DEET at repelling mosquitoes and works just as well against ticks.

Apparently, isolongifolenone derivatives have been used "safely" as fragrances in cosmetics, perfumes, deodorants, and paper products, so, I guess they're claiming that isolongifolenone is safe? Maybe. Benzene is carcinogenic, but toluene (a "benzene derivative") is not. I'd like to see more chemical evaluation data... Oh, yeah, and just because something is "natural" doesn't mean it isn't toxic...

The article doesn't discuss how the new repellent works, but one could assume that it works in a similar way to DEET. Ever since DEET was developed by the USDA and patented by the U.S. Army in 1946, scientists have believed that DEET worked by masking the smell of the host or by blocking the insect's ability to locate a host. Last year, researchers from University of California, Davis, reported groundbreaking research indicating that mosquitoes are repelled by DEET because they simply don't like its smell! If it's that simple, then surely we could find something less toxic that's odorless/pleasing to humans but stinky to mosquitoes?