Wednesday, March 23, 2011

UV light trapping

 A method of attracting moths (& many other insects including beetles, leaf-hoppers, katydids, some types of wasps & other things, too), is to use a light source (either UV or mercury-vapor) in front of a white or light blue sheet like you see below to the left.  In this case, the light is powered by a small generator.  More often, I tend to use small batteries.  You can see a battery in a black, water-proof box in the picture at the right, which shows a UV light in the center of a plastic baffle over a cone funnel.  The sheet system is good when you can monitor the light continually or periodically during the night & the advantage is that nothing need be collected or one can collect only specimens which might be of particular interest.  The funnel system over a large killing jar is often used when taking samples of sites in which all or a majority of specimens that come are being collected or when multiple sites are being sampled on a single night and attending each light is not possible.
Specimens can be sorted in the morning and either be temporarily placed in containers that can be covered & kept chilled in coolers for transport (& I've inserted a picture below showing specimens I sorted into 3 large plastic petri dishes) or they may be  "field pinned".  Field pinning is a way to help protect specimens from damage they might suffer during transport or storage before they can be properly "spread" &/or labeled.  One way to do field pinning is to get each specimen on an insect pin & then place each on a 1" foam sheet.  A method I've used is to then place these foam sheets in large, clear plastic boxes for transport.  A "head" label with location, date and other info (such as the temperature range at night or habitat characteristics) is kept with each group of specimens.  Later, specimens can be dried and given individual data labels and placed in museum drawers for data collection, record keeping, long term storage or for donation to a museum.  

The proper care of each specimen helps ensure it will be of maximum value to ecologists or taxonomists 5, 25 or a hundred years from now.  More on museum collections, another time.