THE SPINNING BEHAVIOUR AND THE SIGNIFICANCE OF SPINNING IN THE EMBIIDS WITH SPECIAL REFERENCE TO PSEUDEMBIA FLAVA ROSS.

The unique feature of the order Embioptera is the presence of gland packed fore-tarsi used for spinning webs or tunnels. The structure of the tarsal glands is well suited to its spinning function. The significance of spinning is a problem much discussed by several authors, and it is generally contended that the web provides protection against predators, besides providing an atmosphere of optimum temperature and humidity. In the present paper the structure of the tarsal glands, the mechanism of ejection of the secretion and the characteristic movements of the foretarsi in the construction of webs or tunnels are explained with reference to a common South Indian species, P. flava. The present study leads to the conclusion that the web undoubtedly gives protection against predators though not to parasites. Protection against the extremes of atmospheric physical factors like temperature may not be effectively accomplished by the web.