Wind turbine woes

Wind turbine near Abilene, TX.  NY Times photo.

When does urban entomology have nothing to do with houses or cities?  Perhaps no better example can be found than the recent email received by my colleague  Dr. Chris Sansone.  He was contacted concerning a wasp problem by the supervisor for a company that provides maintenance services for wind turbines.

If you haven't traveled recently to west Texas, or the corn fields of Iowa or Minnesota you may have missed the sprouting of thousands of towering wind turbines on the vast, windy plains of America.  The size and scope of these wind farms is truly amazing, providing a reported 4.5% of Texas' energy.

Apparently 2010 has been a banner year in many areas for paper wasps. Paper wasps, genus Polistes, are the most common of the social wasps around the state, with nests easily found around most homes and buildings.  Polistes wasps are predators on caterpillars and other insects, and build umbrella-shaped paper nests under tree branches, under eaves of buildings and in windows.

Paper wasps around the entrance to a wind turbine. 
Photo courtesy Aaron Foster.

Most Texans learn sooner or later to respect paper wasps for their powerful sting and their willingness to defend their nests with joint attacks on intruders.  No wonder then that maintenance crews of wind turbines get a little skittish when wasps gather at turbine doors at the ground, inside the tower and, even worse, at 300 feet around the generator housing (nacelle).  Imagine being at the top of one of those towers and getting a face full of wasps!

This phenomenon should not surprise pest management professionals who have observed paper wasp behavior over the years.  Each fall, we see paper wasps abandon their barren nests to seek shelter for the winter.  These overwintering wasps are queens, and they are especially drawn toward structures, especially tall structures in their search for overwintering quarters.  Tall buildings, chimneys and towers are common points of congregation for paper wasps during the months of October and November in Texas.

This behavior explains the high frequency of complaints by office workers (and homeowners) of wasps in buildings during late fall, winter and the early spring months.  Once inside the attic, or false ceilings, of buildings, paper wasps will move around, especially during periods of warmer weather.  These same wasps frequently find their way into living and working quarters, to the dismay of people.  The good news, however, is that without a nest to defend, these wasps have little fight in them.  Therefore, there is little risk of being stung by wasps at this time.

Wind turbine crews aren't the only high fliers worrying about wasps.  Communications tower workers, construction workers and even NASA launch pad workers have discovered the fondness of paper wasps for high places.  When encountering wasps in such locations I have no doubt that the best course of action is to keep calm, wear clothing that can be buttoned tight and try your best to ignore the critters.  Of course you're not getting me up there to test the theory.