Intriguing Bugs in Autumn

Every season has its pests, and some are exceptionally beautiful. Recently I travelled to Ballarat, Central Victoria and was exploring the landscape when my nephew found these fascinating and vividly colored leaf hoppers. Technically they are a type of gum leaf hopper and can be found in Autumn on fresh and new Eucalyptus. These are sap sucking bugs, with piercing mouth parts which suck the fluids of plants for sustenance. They hatch from eggs laid in the bark of trees, usually inside a slit cut by the female to lay around 12 eggs. They cover the eggs with a white frothy secretion and the larvae begin hatching in November and become adults in February.

There are five instars of the nymph, with the first instar resembling a black spider with red eyes. Eventually they instar through to the beautiful bugs you can see in the picture, with azure blue legs, white spots on the wings and a benign expression on their faces! They differ from other leaf hoppers, in that they run around the back of things to get away from you, rather than hopping off and flying short distances. They congregate in groups and share an evolutionary beneficial relationship with ants, who feed off the sugary substance they produce. The ants may also scare other predators away and the two groups lead a rather peaceful existence together on the gum branches. The Eurymeloides species pictured here, only share this relationship with the Iridomyrex species of ants, which also attend female scale insects for sugar. These rather charming bugs mostly pose a threat to the health of eucalyptus species, but the fast growth of most eucalypts can out pace the damage done by these bugs. These leaf hoppers are in the same family as cicadas, the Cicadellidae group.

Another fascinating aspect to Gum leaf hoppers is they secrete brochosomes on their body, and occasionally on their eggs. Brochosomes are intricately structed microscopic granules secreted by leaf hoppers. They are minute hydrophobic particles and help keep the insect cuticle clean. It is thought these super hydrophobic brochosomes protect the leafhopper from the sticky sugary substance it secretes so it will never get stuck to anything. Another theory is that the anti reflective property of brochosomes might make the insect look similar to a leaf and hence aid its survival. These are truly remarkable animals in their adaptations, life cycle, relationship with other insects like ants and evolutionary traits. Definitely worth not killing, as well as being very pretty animals, with particularly cute instar phases.

Gum Leaf Hoppers with juvenile, found at Ballarat Central Victoria, Family Cicadellidae, Eurymeloides distincta

Juvenile leaf hopper with its sugar loving friend, a species of Iridomyrex ant.

Adult Gum Leaf Hopper

Structure of brochosomes exuded from the gum leaf hoppers.