Bees, Hornets, Yellowjackets, etc.
1. Bugs of Washington & Oregon by John Acorn and Ian Sheldon, Lone Pine Publishing, Vancouver, B.C., Canada, 2001.
2. Insects of the Pacific Northwest by Peter Haggard & Judy Haggard, Timber Press Field Guide, Portland, OR, USA, 2006.
3. The Butterflies of Cascadia by Robert Michael Pyle, Seattle Audubon Society, Seattle,WA, USA, 2002.
4. The Guide to Butterflies of Oregon and Washington by William Neill, Westcliffe Publishers, Englewood, CO, USA, 2001.