Corralitas Drive: Wasp Gall Snatched Quickly By Predators

Photo: Diane Edwardson, August 4, 2014.  A huge, tennis ball-sized gall (a woody growth containing wasp larvae) appeared, seeming overnight, on the Blue Elderberry Tree in our backyard.  The next day, it was gone.  (Click on photo to enlarge.)

Galls are formed by trees in reaction to a gall wasp laying eggs in the branch.  The larvae grow in the gall (which does not harm the tree) until they break out of the gall as mature adult wasps.  According to Bug Guide, there are more than 750 species of gall wasps in North America.  In this area, you usually find galls on Coast Live Oaks.  I'd never seen a gall on Blue Elderberry.

Photo: Diane Edwardson, August 4, 2014.  Since this gall was so large, I noticed it immediately.  The next day,  it was completely missing.  I suspect the marauding raccoons found an good source of protein in the larvae.  (Raccoons stripped the fruit trees in our yard this summer.)

Semi Tropic Spiritualists' Tract: Coast Live Oak Gall Wasp, Stuff You Missed This Year

Photo: Diane Edwardson, February 10, 2012.  I'd always wondered about those mutant golf ball sized fruits you occasionally see on the native Coast Live Oak in the area.  (Click on photo to enlarge.)

 

Last week's Christmas Fungus Frenzy had me wrongly thinking puffball mushroom, but they're always on the sunny, east facing side of the tree. 

 

Gall Wasps lay their eggs in the buds of native Coast Live Oak Trees.  The tree reacts by creating the protective casing or "gall" around the growing larvae.  When holes appear in the gall, the larvae has matured and left the gall.  Another mystery solved.

 

"Stuff You Missed This Year" is our annual wrap-up of interesting photos we didn't get a chance to run in a timely manner.