2019 by Amanda Whispell

What Controls Physiological Color Change in Argia apicalis?

Argia apicalis - male

I am very interested in the physiological processes that induce and control the color change that occurs in both A. apicalis males and blue-form females during MEs.  Looking more closely at the anatomy of both the male and the female, to see if there is the potential for some form of mechanical stimulation occurring at either the tandem linkage site, or during actual copulation, that could be initiating the color change.  I am currently in the process of cleaning and taking scanning electron images of A. apicalis male terminal segments and female prothoraces and mesostigmal complexes.  The goal of this work is to find sensilla in locations where the males make contact with the females during tandem linkage and locate any tactile receptors that might send a signal to the either sex to ‘change color’. 

A. apicalis  female mesostigmal complex

© Amanda Whispell

I would also like to look at the potential for a humoral, hormonal, or neural stimuli to be coordinating the physical change that occurs in the cuticle itself.  Looking at the histology of males in both DP and BP would be a good start, subsequently moving forward to look deeper into the hows and the whys.

A. apicalis  male terminal segment

© Amanda Whispell