Extraction of Lipids from the Precursor of the Stylet-Sheath Material of a Pentatomid

Abstract

IT has been reported¹ that the stylet-sheath material of the American milkweed bug, Oncopeltus fasciatus (Dall.), yields oily sudanophil droplets when warmed in chlorated nitric acid. In the three-lobed principal salivary glands, the contents of the anterior and lateral lobes have been identified as the precursors of the sheath material, and the contents of the lateral lobe show stronger sudanophilia than the contents of the other lobes². On this evidence, it was suggested that lipid is present in the sheath material and is elaborated in the lateral lobe ; and on the basis of the reaction of Oncopeltus sheath material to the Liebermann–Burchardt test for sterols, it was concluded that a steroid might be present. The following concerns the presence of lipids in the sheath material and its precursor in the salivary glands of an Australian pentatomid, Eumecopus sp., which feeds on eucalypts.