Talk:Pachnoda sinuata

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If this article is to be expanded, the German article can be used as basis. FrancoisJordaan (talk) 00:07, 2 January 2010 (UTC)

Rah! I'm a monstah

This photo over at scarabaeidae shows the insect mimicking something, judging by the name; this isn't mentioned in the text. What is it mimicking? -Ashley Pomeroy (talk) 12:47, 13 November 2010 (UTC)

I was careful in my description not to inject original research, so I didn't want to speculate. But I'm hoping viewers find its resemblance to a dangerous animal with eyes and gaping mouth indisputable! I have received the following comment from a Professor at the School of Biological & Conservation Sciences, University of KwaZulu-Natal:

What you have noticed is something that only a few of us are very familiar with, particularly those regularly observing and collecting fruit chafers (Scarabaeidae, Cetoniinae), the group in which your beetle, Pachnoda sinuata flaviventris (not simply the nominal P. sinuata) belongs. Most of these beetles feed on nectar, fermenting fruit and sap flows, but do not have a long feeding apparatus like the proboscis of butterflies and moths, which would allow them to stay vigilant at the surface of the flower/fruit while sucking the juices using an extensible device. They have to dig in, in order to access the target food and this generally results in them having to stick out the tip of the abdomen, known to the professional as "pygidium". Essentially they feed with their "bum in the air". Because it is at this stage the most vulnerable part of the animal's body, the pygidium of fruit chafers has undergone special adaptation to minimize losses from predators. As part of these are the sclerotization of its surface with multiple layers of chitin and the appearance of warning/deterring ornaments, such as eyes and teeth - of the kind exhibited by your specimen of P. sinuata flaviventris. Most fruit chafers species indeed have spots and lines (generally white) on the pygidium, often combined with elytral decoration, to avoid becoming "somebody's else dinner".

Although your specific example has not been reported in the literature, as far as I know, there are many similar cases discussed in popular books, such as: 1) "Evans & Bellamy, 1996, An Inordinate Fondness for Beetles, Henry Holt Publ. (see section "How to Avoid Becoming Dinner", pp.118-129); 2) Holm E, 2008, Insectlopedia of Southern Africa, Lapa Publ. (see sections on "Colour Vision" and "Camouflage" , pp. 146-166).

I have neither of the books he mentions. So it would still seem that, for me to make any specific claims of animal mimicry, would be disallowed as original research. FrancoisJordaan (talk) 13:58, 30 March 2011 (UTC)