Dear Scientist, We have some mail ordered caterpillars
in our classroom that came from Insect Lore in CA. They appear healthy,
but seem to be producing a web like material. My students are wondering
how it is that caterpillars make webs? And why? Do you know the answers
to this question?
Caterpillars have spinnerets which produce a silky material. This silk drys
when it is exposed to the air. The caterpillars use it to make webs and
cocoons. This can be for food, protection, and eventually a safe place to
change into a butterfly!
I work with Pieris rapae which is the Cabbage White ("Brassica") butterfly.
I don't know what kind of caterpillars you are working with, but brassica
butterflies have silk glands in their feet. This helps them to hang on to
surfaces. They also use the silk glands to anchor themselves to the spot
they will make their crysallis (cocoon, pupa) on.
Click here to return to the Zoology Archives
Update: June 2012