Subject: Please identify this insect
Location: Wallan, Victoria. Australia
December 3, 2012 4:39 am
Our gum and bottlebrush trees have been covered with tens of thousands of these green flying insects. Please help with identifying the insect and what are the dangers to our trees.
Thank you in advance.
Signature: Dean and Rose Joyce
Dear Dean and Rose,
We quickly identified your beetles as Plague Soldier Beetles, Chauliognathus lugubris or Chauliognathus pulchellus on the Brisbane Insect website. The site indicates “Sometimes we found the swarms of Plague Soldier Beetles. The aggregations are believed for the purpose of breeding. Most of them in the aggregation are mating.” Despite the common name, they are not considered a threat to the plants, though large numbers might be considered a nuisance. Soldier Beetles, according to the Brisbane Insect family page for Cantharidae: “are abundant on flowers and foliage where they feed on nectar, pollen, or other small insects.” Both Gum and Bottlebrush produce pollen, so there is an ample food source on those trees. Additionally, Soldier Beetles are beneficial as they feed on insects that are injurious to the trees like Aphids and Hoppers. The Wild World of Pests website states: “Every spring I marvel at the numbers of insects devoured by soldier beetles. They’re real troopers in the war on damaging insect in my landscape. … Between the soldier beetles and the ladybugs I don’t have much to worry about, when it comes to aphids. Soldier beetles, sometimes known as leather backs are voracious feeders. The larvae are quite efficient at dispatching aphids and other plant pests, including spider mites, grasshopper eggs, gypsy moth caterpillars, eastern tent caterpillars birch leaf miners, elm leaf beetles, oak webworms, lilac leaf miners, cucumber beetle larvae and many more garden pests. The adults devour large quantities of aphids, but also enjoy nectar and pollen, so it’s a good idea to have lots of flowers around to attract them.” Since the Brisbane Insect website indicates that these large aggregations might be related to mating behavior, we are tagging this posting as Bug Love.