Silk Production in the Cheyletidae (Acarina: Arachnida)

Abstract

WHILE examining some grain infected with tyroglyphid mites, I found a specimen of Cheletomorpha lepidoptorum Shaw (=venustissima Berlese), which had just finished laying eggs. About six eggs were scattered on the ground, and the Cheletomorpha was moving backwards and forwards, covering them with a sparse network of silk. In this mite, the mouth is at the end of a gnathosoma, which is shaped like a cone and completely encircles the cheliceral stylets. The silk was coming from the mouth in the form of a very fine thread, which was stretched from side to side over the eggs, the pedipalpal claw being used for manipulating it at times. Unlike Cheyletus eruditus Schrank, which remains crouched over its eggs until the larvæ emerge, the Cheletomorpha took no further interest in the welfare of its young, but wandered away to lay a few more eggs in another place.