Monday, August 24, 2015

Insecticide Resistant Lice

Head lice move across a nit comb. (Kevin Dyer/iStock)
The new school year is often accompanied by increased reports of head lice. And according to a new paper delivered at the American Chemical Society and reported last week in, this year’s head lice may be a bit more problematic.

In the paper, North Carolina is among 25 states shown to have head louse populations that are resistant to the most commonly used head louse shampoo treatments, including pyrethrins and the pyrethroid insecticide permethrin. In 104 out of 109 lice populations already analyzed, the authors found high levels of gene mutations that make lice indifferent to these over-the-counter treatments. The team is still analyzing data from the other 25 states.

Researcher Kyong Sup Yoon, lead author of the study, points out that "Just one louse that manages to survive a pyrethroid treatment can live for up to a month and lay five eggs a day. Multiply that by an elementary school, a community, and soon you’ve got plenty of resistant lice.”

The good news is that there is no reason to panic. There are new, non-pyrethroid options available through your doctor. These products will likely be more expensive, however.

Regardless of what product you use, pay careful attention to head inspection and combing after treatment. Using two methods (insecticide plus combing) is almost always better than one method when it comes to controlling lice.

Monday, July 27, 2015

Why Cockroaches Die on Their Backs

Below is a link to an article featuring Dr. Coby Schal with NCSU's Department of Entomology.

Coby Schal is a professor of entomology at 
North Carolina State University

Thursday, July 2, 2015

What's That Smell? The True Odor of the Odorous House Ant

When talking to folks about the odorous house ant, you’ve probably told them that the ant smells like rotten coconut when it’s crushed, after which they inevitably give you a “look” – one that tells you they think it’s disgusting that you readily squish ants! 

While the freshly crushed odorous house ant does produce a definite odor, describing it as “rotten coconut” never said a lot to me, namely because I have never smelled a rotten coconut! I have always thought the odorous house ant produced a clean smell, almost like glass cleaner, with more of a “punch.” 
In an effort to provide more accurate information on just how the odorous house ant smells, Clint Penick and Adrian Smith conducted a recent study investigating the volatile compounds released by the odorous house ant and the items most commonly associated with their scent. 

The vast majority of online sources identify the odor of the odorous house ant as “coconut-like” (Fig. 1A). This ran counter to the results of a smell test that Penick and Smith conducted as part of their study. In the smell test, participants most identified the smell of a freshly crushed odorous house ant as “blue cheese,” followed by “other” as a close second (Fig. 1B). The most common write-in candidate for “other” was cleaning spray (very similar to way I have always described the smell of odorous house ants!).

When Penick and Smith also used gas chromatography-mass spectrometry to determine the exact chemical composition of the odorous house ant scent. They found that the major component of the odorous house ant scent was a methyl ketone (Fig. 2) that has actually been identified in other ant species as well. As in turns out, the most prominent compounds associated with blue cheese are also methyl ketones. No methyl ketones were found in fresh coconut. Once coconut turned rotten, however, it released the same methyl ketones found in blue cheese. Interestingly, the microbes that turn coconut oil rancid – Penicillium mold – are the very same microbes used to make blue cheese!

So, what exactly IS that smell? According to Penick and Smith’s results, the odorous house ant odor points to blue cheese, with a cautious nod to rotten coconut. They emphasized cautious because it’s not the “coconut” in rotten coconut that smells like the odorous house ant, but the “rotten.” To sum up, odorous house ants do not smell like coconuts. They smell like blue cheese. Or you could say that they smell like coconuts that have been colonized by Penicillium mold that causes the coconut oil to produce an odor similar to blue cheese.

Tuesday, June 23, 2015

EPA Publishes Proposal To Mitigate Exposure to Bees From Acutely Toxic Pesticide Products; Notice of Availability

On Friday May 29, the EPA published a proposal to mitigate exposure to managed bees from pesticide products from foliar applications. The EPA’s proposal would prohibit the foliar application of acutely toxic products (neonicotinoids) during bloom for locations with bees on-site and under contract. Current neonicotinoid product labels contain a 48 hour notice exception, which will be removed from the label. This proposal was detailed in the President’s National Strategy to Promote the Health of Honey Bees and Other Pollinators released last week. The proposal is very limited to foliar applications when managed pollinators are on the property under contract.
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