Blue lupines and wild bergamot were blooming near the top of
Flagstaff Mountain, attracting an assortment of butterflies. I
was enjoying the fluttering when I noticed a northwestern
fritillary, Speyeria hesperis, hanging upside down and
motionless from a bergamot. A goldenrod crab spider, Misumena
vatia, had its fangs embedded in the butterfly's body and was
sucking out its fluids. This spider was quite a hunter, for it
had killed an insect bigger than itself. Although crab spiders
spin silk for drop lines, they do not build webs to catch prey.
Instead, they find a spot where they are well camouflaged and
lie motionless, waiting for an insect to approach. When an
insect gets close, they pounce, grab and inject venom. Spiders
do not have jaws like vertebrates, but manage with two pairs of
mouthparts. Fangs impale the prey and inject venom. Pedipalps,
which look like a pair of small legs, are used to manipulate
tiny prey items and macerate and liquefy tissue. Spiders inject
enzymes to dissolve tissue and then s