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Giant Green Slantface - Acrida conica
This rather strange looking insect is a grasshopper from the Acrididae family, only these have very long gangly legs that hang down as they fly, so once seen are easy to recognise again in flight. There is only one species in the Acrida genus, but it is very widespread in the Eastern States, although not in Tasmania and southern Victoria. It is also found across most of Central Australia and into northern WA, then down most of the West Coast. However it has not been recorded east of the Albany district (across the Nullarbor) to Port Augusta in SA, a distance of 1800 km or 1120 miles, so finding Acrida conica at Esperance has reduced that gap by 400 km or 250 miles.
The common name of Giant Green Slantface comes from the elongated slanting face, plus it is mostly green, with a much less common brown morph as shown above. The giant part is because they are quite large with the female being to 8.5 cm (nearly 31/2 “) in head/body length (males to 5.5 cm or 21/4” in length), but both appearing much larger due to their broad sword-shaped antennae and very long legs.
Whether these grasshoppers are green or brown, they are well camouflaged when on a similar coloured background. If disturbed they will take off and slowly flutter 5-10 metres before dropping down and if disturbed again, will again fly off until they locate a similar coloured background, where they will remain motionless and can be approached more closely.
This year 2012, I have seen several of these Giant Green Slantface grasshoppers just east of Esperance, generally in moist low-lying areas, possibly as this habitat offers a variety of different coloured backgrounds on which they can rest and feel safe. However, I do not recall seeing them in previous years or not that I noticed, so it will be interesting to see what happens in future.
Further Reading: A Guide to Australian Grasshoppers and Locusts by Rentz, Lewis, Su and Upton.