Salivary gland structure of Ctenarytaina eucalypti (Maskell, 1890) (Hemiptera) and phloem exudate in Eucalyptus globulus Labillardiere, 1799 (Myrtaceae)

摘要

The structure of the salivary glands of the free-living aphalarid Ctenarytaina eucalypti, which infests multiple species of Eucalyptus in Australasia and has been introduced into many other regions of the world, is described and illustrated. The principal salivary gland is multi-lobed whereas the accessory gland is tubular. 1-D electrophoresis revealed proteins of approximately 58 and 64 kDa in the salivary gland extracts and proteins of similar molecular weights in the extracted plant exudates, including phloem, from infested leaves and tender shoots of E. globulus. Proteins that could fall within this range include, but are not limited to, glucose-methanol-choline-oxidoreductase (53-66 kDa), Zn-binding dehydrogenase (67 kDa) and esterase (65-96 kDa), in addition to cytochrome P-450 (50-55 kDa), trehalase (56 kDa), amylase (50-75 kDa) and lipase (48-52 kDa). Previous studies indicate that glucose-methanol-choline-oxidoreductase, Zn-binding dehydrogenase, cytochrome P-450 and trehalase suppress plant-defence mechanisms, whereas the cell-degrading enzymes such as amylase, lipase and esterase have a possible role in enabling C. eucalypti to insert its stylet into leaf and shoot tissues of E. globulus.