The head of a Green Grocer cicada,Cyclochila australasiae (Hemiptera). C. australasiae is widely found in coastal regions of Australia from South Australia to Queensland. The insect spends 6 or 7 years as a nymph underground,feeding on the sap of plant roots. Eventually,in early summer,the mature nymph digs its way out of the ground and climbs a nearby vertical surface. Clasping this substrate,the nymph's exoskeleton splits,allowing the adult insect to emerge. This picture,taken in Warrandyte Victoria in early December,is of an adult insect on the bark of a eucalyptus tree. It shows two compound eyes and three simple eyes (orange),known as ocelli. Compound eyes consist of many small individual units called ommatidia which produce a mosaic-like image. The function of ocelli is uncertain,but may be related to rapid perception of changes in light levels,assisting stable flight |