[Odonata-l] Color change near emergence

[Richard Rowe]

Laura Elizabeth McMullen wrote:
> I have noticed in some Gomphidae larvae that there is a distinct  
> difference in coloration between individuals of the final instar,  
> especially in the eyes and wingpads.  While some individuals have eye  
> and wingpad coloration similar to all smaller instars, other  
> individuals have eyes that look "pasted over" and wingpads with very  
> distinct swirling patterns in them.  I assume to attribute this to the  
> changes in internal morphology and change to the adult form, and that  
> those individuals with the changed coloration are very near emergence.  
>   However, I did not notice a gradient of changes- only a very  
> distinct change.  Does anyone know why only the distinct change would  
> be evident, and especially does anyone know of any papers or sources  
> that discuss this coloration change?
>   
It is called a pharate (= hidden) adult. In the later stages 
metamorphosis is quite rapid so the changes will appear 'suddenly'. This 
is covered (with literature entries) in Corbet 1999 p234ff. An older 
(well it would have to be!) shorter account appeared in Corbet 1962 
(http://medusa.jcu.edu.au/corbet about p100)

Richard

-- 
Dr Richard Rowe
Zoology & Tropical Ecology
School of Marine & Tropical Biology
James Cook University
Townsville 4811
AUSTRALIA

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