BP Shiel, CDH Sherman, MA Elgar, TL Johnson, MRE Symonds (2015) Investment in sensory structures, testis size and wing coloration in males of a diurnal moth species: trade-offs or correlated growth? Ecology and Evolution 5: 1601-1608 LINK
What’s it about?
We investigated whether male painted-apple moths trade-off investment in sensory structures. The theory being that these structures are costly to produce and hence some individuals may choose to invest more in antennae (to find mates) at the expense of eyes of testes. We didn’t find any such trade-offs, in fact investment in eyes and antennae are correlated (even independent of body size). Even more surprisingly we found an unexpected correlation between testis size and wing coloration, which raises questions as to what is going on there. We speculate a bit about that.
What’s the story behind it?
Brett was an honours student in the lab back in 2012 (one of my first at Deakin), and the idea of his project was original to look at relationships between antennal size and sperm morphology. However, we really struggled to get a lab population of painted apple moths going, partly because there just weren’t many around that we could find, and also partly because, well those moths are not actually violently easy to culture. Consequently it became apparent we’d have to change the focus of the project and look more at already caught specimens (which PhD student Tamara had caught some years previous). Consequently we focussed on a correlational morphological analysis. I think in the end Brett did a great job in turning something of a sow’s ear into, if not a silk purse, than an acceptable leather wallet.