A Few More Beetles
Longicornes or Long-horned Wood-borers, Cerambycidae
The larvae of cerambycids live is wood, mostly dead or dying wood. Of course, a rainforest provides ample habitat and this group is represented by dozens of species some small and others very large. The natural histories of most species are as yet unknown. And it is surprising that a group of such economic importance, and of appeal to collectors, Australian as well as foreign, that comprehensive guide to species exists.
Meet Rosenbergia megalocephala van der Poll, quite a mouthful but a large an impressive longicorne that infrequently comes to our lights.
Platymopsis nigrovirens is an attractive species that sits on twigs during the daytime in a cryptic position. Other members of the Lamiinae, like the one below, do the same.
This is one of many lamiine cerambycids. It is a good example of protective coloration.
This species of Phoracantha has a most peculiar resting stance. On a tree trunk it looks like anything other than a beetle.
One of many unidentified species that frequents the Kuranda rainforests.
This prionine will be familiar to northern readers as both Prionus and Ergates are commonly found in coniferous forests where the larvae bore in dead wood. In Australia also there are a number of species but their taxonomy is still to be done. They always attract attention when the buzz into lights. They have powerful mandibles and only the most adept of the Black Butcherbirds can make a catch without being injured. They seem to prefer these beetles over others at the lights. This may be just a reaction to the large size of the beetles but it may be something more. These beetles may be more nourishing than may of the others.
In the first volume of his monumental 5 volume series on the Australian Weevils, EC Zimmerman states that “... the Australian weevil fauna contains more species than all of the Australian mammals, birds, reptiles, fishes and amphibians combined plus various invertebrate groups.” He felt the Australian fauna probably contained 1000 genera and up to 8000 species. Weevils are almost everywhere, in almost all terrestrial habitats.
There is a nice selection of species in the rainforests but you have to look for them. Many are in decaying timber, others in the leaf litter and in developing seeds and fruits. Most are very small and go unnoticed. A nice sampling comes to the lights and a few are presented here. While the majority of species are in the weevil family proper, the Curculionidae, there are many in related families. Like the Brentidae and the Anthribidae.
Anthribidae The Fungus Weevils
If cryptic coloration fascinates you, try to find the Dendropemon weevil in this shot. The family is best developed in areas of high rainfall. This is because they may feed on fungus. as Zimmie points out we really don’t know because the observations just haven’t been made.
These odd weevils are represented in Australia by a few genera and not too many species. They seem to be primary wood-borers, boring in freshly felled timber where they probably feed on fungi. However, some are known to bore in living tissue and there is a cadre of species that live with ants. Ithystenus hollandiae (Boisduval) comes to lights in the wet season. Males joust with one another on logs. They guard egg-laying females as well.
Curculionidae True Weevils or Broad-nosed Weevils
The majority of species reside in this family and range in size from the small species you find in birdseed or cereal products to some real giants in Australian woodland and heaths.
The long-nosed Weevil, Sipalinus gigas granulatus (Fabricius) is a large and rock-like species that flies to the lights occasionally. It has long legs used to grip bark and twigs. In nature it often occurs in groups on suitable logs. the larvae can cause considerable damage to harvested logs awaiting processing.
The New Guinea Sugarcane Weevil, Rhabdoscelus obscurus (Boisduval) is a pest of sugarcane and was probably introduced into Australia. Unfortunately for those who like to breathe clean air, the burning of the sugarcane prior to harvest probably helps to destroy the weevils. This weevil also attacks and kills palms. It is of concern to homeowners and horticulturists because of the devastating effects it can have on ornamental palms. By the time growers notice the problem, it is too late. The larvae tunnel in the tissues and eventually kill the palm.
Leptopis malefictus (Lea) flies to the lights on the odd occasion. It is in a large genus with species all over the country. It is often associated with acacias.
Zimmerman, E. C. 1993. Australian Weevils (Coleoptera: Curculionoidea) Volume III Nanophyidae, Rhychophoridae, Erirhinidae, Curculionidae; Amycterinae, Literature Consulted. CSIRO, American Entomological Society, pp 1-854.
Zimmerman, E. C. 1994. Australian Weevils (Coleoptera: Curculionoidea) Volume I Orthoceri Anthribidae to Attelabidae The Primitive Weevils. CSIRO, American Entomological Society, pp 1-741.