The Physiological Division of Labour in the Salivary Glands of Oncopeltus F Asciatus (Dall.) (Heteroptera: Lygaeidae)

Abstract

The physical and chemical characteristics of the contents of the different lobes of the salivary glands of O. fasciatu8 are compared with the characteristics of the two types of salivary secretion: namely the solid "stylet sheath" and the liquid "watery saliva". It is concluded that the anterior lobe contributes most of the sulphydryl groups that form the disulphide bonds in the sheath material, but that the lateral lobe provides most of the bulk of the sheath; that the posterior lobe contributes the digestive enzymes found in the watery saliva; that the accessory gland secretes water that can dilute the watery saliva; and that the accessory gland also provides the polyphenol oxidase that is sometimes found in the watery saliva and is always secreted along with the sheath material. Surgical isolation of the accessory gland gave no positive information on the function of the polyphenol oxidase.