by Pat Jaquith
pat@westvalleynaturalists.org
Click on photos to enlarge them.
Spiders can be called creatures of one summer that hatch or emerge from diapause as the weather warms and reach maturity in late summer. These predatory insects employ various means to capture their prey.
Read more: Some Spiders in West Valley
The large Banded garden Spider lays in wait at the edge of the web; when it senses an insect in their web, it attacks with a bite that stuns the prey and liquifies their inner parts. It encases the stunned insect cocoon-like before devouring the liquid nutrients.
All of the above Orb weavers catch their prey in a trap they spin.
Funnel-web Spider Clear-wing Grasshopper in funnel web
The Funnel-web spider spins a sheet-like web shaped like a funnel on the ground. The spider usually lies in wait at the end of the tube; when an insect becomes entangled, it pulls the prey down into the ground where it devours it.
Crab spiders, sometimes called ambush bugs, lie on a flower in wait for an insect to visit the plant. When the visitor becomes engrossed in its work, the Crab spider dashes in and paralyzes the insect with venom in its bite.
Goldenrod Crab spiders are able to change color to match the flower it chooses. It takes a few hours after it arrives at the flower where it will spend time in wait. Most of the Goldenrod Crab spiders I have seen were colored like the one on the Spotted Knapweed, regardless the color of the flower.
The Cat-faced spider at right was gone the next time we checked this web site under a window sill. In its place was an egg sac. These spiders die after laying their eggs, just before a hard frost. The eggs will hatch in spring and live to predate on other insects around the house.
This Fierce Orbweaver (identified with help of iNaturalist), was climbing up the door to my house. Not recognizing it, nor wanting to invite it inside, I very cautiously lured it away with a stiff plant stem. If I got too close, it reared back and waved its front legs as if boxing. While it moved across the driveway, it left a string of silk from the hole visible in the right photo; it seemed to use it as an anchor to help flip onto its back. The Fierce Orbweaver is listed as a native species in Montana.
Wolf Spider with spiderlings on her back
Female Wolf Spiders carry their egg sac on their back; when they hatch, the babies ride there. They will fall off in leaf litter where they go into diapause until spring. This spider was crossing a sun-warmed driveway in early evening in September.
Nest of spiderlings on May 23. While I watched, the babies would crawl up a blade of grass and float off on a spinneret in the wind. I did not wait long; only a few had dispersed over the nearby wetland.
