Monday, September 17, 2012

Springtail Invasion

Springtails hit the wall
Our friend Georgia saw thousands of tiny insects crawling up the side of her house.  They seemed to be emerging from the wet soil during a rain storm, covering a wide area.  They were a gray color,  less than 1/16 of an inch long and they tended to hop.  Her questions were what are they, could they become a problem by invading the house and should they be sprayed?

She happened to have her old dissecting microscope left from her days as a biological microscopist and was able to get some magnified pictures.  We sent the pictures to Dr. Chris Barnhart who identified them as springtails, a harmless horde.  With this information, she spared thousands of lives.

High magnification- Georgia P.
Springtails (Collembola) are hexapods (six legs) but are no longer considered insects by some researchers based on DNA studies and anatomical variations.  Insects have external mouth parts while springtails' mouth parts are internal.  These authors argue that springtails and their 6-legged insect cousins evolved from separate lines.

Although a few species are found up in trees or on the edges and surface of ponds,  many species are found in damp soil and leaf litter.  They consume dead plant and animal matter, eventually contributing to the creation of soil.  They also consume fungal mycelia and transport mycorrhizal fungi which contribute to
the growth of plants.
 
Furcula set to spring- Wikimedia
They get their name from an escape mechanism that allows them to "jump."  A structure called a furcula is attached to the abdominal tip.  It folds under the body, held under tension like a spring.  When danger approaches it snaps, with the springtail sailing quickly in the air.  They can jump as high as two inches, 30 times their body length,  the equivalent of a 5'10" man jumping 175 feet straight up...from a standing start!  While not quite in the league with fleas, it is
still pretty impressive considering they aren't using their legs.

End-to end, 16 per inch
Springtails commonly emerge in massive numbers in homes or other human structures such as Georgia reported.  Although they don't bite like fleas or carry disease, their migrations can be alarming and lead to calls for help by homeowners.  They usually die off in a week.  Prevention includes eliminating damp places for them to gather.  The ucdavis.edu website has advice on management.

Thanks to the ever observant Georgia Pozycinski for the pictures and the call.