Boogie-woogie Aphids

 

Beech Blight Aphids (Grylloprociphilus imbricator) 
on American Beech (Fagus grandifolia)
Rowan County, North Carolina.

A friend contacted us about a white growth on a beech tree that wiggled when disturbed.  After a visit to view this phenomenon, some photos, videos and research, we figured out this was a group of small insects called Beech Blight Aphids (Grylloprociphilus imbricator).  These aphids were on a single branch of an American Beech tree (Fagus grandifolia).  Another common name for these odd insects is Boogie-woogie Aphids.  Unless you listen to the Andrews Sister you probably don't get a whole lot of boogie-woogie in your life. But we got a good dose with these aptly named Boogie-woogie Aphids. 

 

A single branch of American Beech with hundreds 
of Beech Blight Aphids.
Rowan County, North Carolina. 

Beech Blight Aphids.
Rowan County, North Carolina. 

Beech Blight Aphids have a dark body covered with long, white, waxy filaments.  If attacked, the predator gets a mouth full of wax and the aphid gets away.  The aphids cluster on twigs and leaves of American Beech where they feed on the tree sap.  When aphids feed, they insert their piercing mouthparts into the phloem cells in the vascular tissue of the tree.  Phloem transports organic molecules, particularly amino acids and sugars throughout the tree.  To accomplish this movement of molecules the phloem is under pressure.  When an aphid pierces a phloem cell the insect does not have to suck up the sap.  The pressure in the phloem forces the nutrients into the digestive system of the aphid.  Beech Blight Aphids absorb some of the phloem molecules but the pressure forces much of the material out the anus of the insect.  This rich exudate is called honeydew and is food for ants and nutrients for sooty mold.

 

Video of Beech Blight Aphids aka Boogie-woogie Aphids. 

 Rowan County, North Carolina.

When threatened, the massed aphids point their filament-covered abdomens into the air and wave them back and forth.   These are the boogie-woogie moves that gave Beech Blight Aphids the funny name.  This behavior is thought to provide protection from predators.  

Beech Blight Aphids.
Rowan County, North Carolina. 

Despite their large numbers, Beech Blight Aphids seem to cause little harm to the beech trees they inhabit.  So if you run across these aphids, don’t worry about beech trees and enjoy the show.