Yellowjacket wasps - you'll be surprised what the adults eat.

Wasps building a nest inside the sign at Mission Recreation Park by the H2O Center, Kelowna.

Wasps like holes.  The voids in dirt, soffit, siding, and even metal structures like the sign housing in the above photo all lure a recently emerged queen wasp in.  Her goal is to find a small entrance, easily guarded, into a cavity large enough to build her coming empire.  She, without any help, forages for nest materials (chewed wood fiber that she mixes with her saliva) and builds the first cells that will eventually house her brood.  

Once the initial few cells are formed, she lays an egg in each and then hunts for food.  The developing larvae require protein-rich food consisting of whatever invertebrates are available.  The prey is chewed into a paste and fed to the young.  Now, here is the weird thing.  The larvae emit a sweet secretion called "larval nectar" that is the primary food of the adults.  The adults will also take sugary secretions from flowers or other sources.  

Wasp hunting for sources of protein.

The larval nectar is produced from the salivary glands of the developing larvae.  It contains sugars, free amino acids, and water.  In the fall, the larvae produce less of this and the hungry adults have to find other sources of energy, which is why they become more aggressive.  

The wasps in the top image left me alone as I photographed them only a few days ago.  But you can bet that when the fall comes, they will be less benevolent.  

Thanks for reading.    

Eric Svendsen     www.ericspix.com