Monday, 21 April 2014

A Thing of Beauty

Lindsay Fisher  took this photo of a rare yellow morph of the Serrated Bush Katydid, Paracaedicia serrata Brunner. Odd colour morphs of this and other katydids appear from time to time. In fact, a pinkish morph, photographed by Jack Hasenpusch, was on the cover of the Guide to Australian Katydids.
P. serrata is normally a green katydid.
This katydid lives in the coastal rainforests of northern Queensland. It probably lives well off the ground in dense foliage. It, like many others of its subfamily, probably feeds on foliage. It frequently comes to lights after dark.
It gets its specific name from the serrated appearance of the hind femur. The serrations are actually stout spines. It is a robust species and large (approximately 60-70 mm in length) and would present formidable opposition to a bird or lizard that attempted to subdue it.
The structure of the thorax with its expanded musculature is responsible for its hump-backed appearance. This results in its strong flying capabilites.
Eye colour and patterns on the head of katydids are generally species-distinctive but taxonomists studying dead bugs are usually unaware of the colours because they are not preserved with most preservation methods and they also fade with time. This is a disadvantage because they are not only beautiful but add sets of characters that can be used in classification.
The morphology of the male clasping organs provide one of the most distinctive features of katydids. The teeth fit into equally distinctive pockets on the abdomen of the female. This has been called the "Lock and Key" theory in the distant past. If the key is not of the structure to fit the pocket, then there is no successful copulation. This is probably true most of the time but it is the odd occasion when a mating takes place between members of different species that hybrids can result.

Of interest to a limited number of readers is a recent proposed name change to the classification of katydids. Formerly the family to which this and the greater majority of katydids belong is the Tettigoniidae. This family has been divided into many subfamilies and from time to time these subfamilies have been raised to family status. In general, these escalations have been ignored by taxonomists.

This katydid is a member of the subfamily Phaneropterinae and has been once again elevated to family status, now the Phaneropteridae. This changes the status of hundreds of genera. This change was based on a suite of morphological characters borne on extant and fossil species and DNA analysis. Four subfamilies are included in the new Phaneropteridae: Mecopodinae, Phyllophorinae, Pseudophyllinae and the Phaneropterinae. Only time will tell if taxonomists accept these changes but the evidence seems overwhelming at this point.

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