Yellow-green caterpillars varying in size from .5 inches to 1.5 inches eating my wisteria. They have what appear to be stripes around the girth giving them a closed accordion like look. The large one has orange-yellow eyes. I discovered that they ‘glue’ together 2 leaves to form a leaf- cocoon or leaf- cave.
Your caterpillar will turn into the silver-spotted skipper butterfly.
These skippers are found throughout most of North America along roadsides, meadows, gardens and other plant filled open areas. This is one of the largest and most common of the skippers. The silver spot does make it easy to recognize.
The caterpillar feeds on foliage of the legume family (bean family) including your wisteria…other plants include kudzu,false indigobush, alfalfa, locust trees, stick-tights, beans. These caterpillars are not a garden pest.
Interesting fact from the Univ of FL entm dept: Insect frass (droppings) may provide chemical cues for parasitic wasps to the location of prey insects. Many caterpillars that live in leaf nests, including the silver-spotted skipper, forcibly eject their frass for considerable distances to eliminate these chemical cues. Silver-spotted skipper larvae utilize their anal comb to throw their frass a distance up to 38 body lengths.
Bugguide website says that the caterpillars hide during the day in silken nests among foliage, emerging at night to feed. There is one generation in the north and two in the south. They do overwinter in the pupa stage.
This insect does not bite or sting.
Moni has an ebook “Garden Insect Pests of North America – Pictures for Identifying and Organic Controls” Check it out!