In the 1st of 3 stages of cocoon spinning,Campoletis sonorensis(Cameron) spun the loosely meshed outer layer of the cocoon. The 2nd stage began when the parasitoid initiated construction of the more closely woven inner layer. During the 3rd stage of spinning, the inner layer was lined with a thin, translucent sheet of silk.C. sonorensiswere generally incapable of repeating spinning operations when removed at various stages of spinning; only those which had been removed from half completed or completed outer layers were able to spin a normal cocoon. Cocoon spinning was affected by the moisture content of the spinning substrate, but not by atmospheric moisture.