Preliminary results on the evolution of egg-powdering behavior will be posted soon. You can look for me in the upcoming Willi Hennig Society Meeting in Paris and International Congress of Entomology in Brisbane, where I will be presenting talks on this.
While you wait, you can visit Roman Rakitov's WEBSITE for more information of leafhopper behaviors or read his recent paper:
Rakitov, R. A. 2004. Powdering of egg nests with brochosomes and related sexual dimorphism in leafhoppers (Hemiptera: Cicadellidae). Zoological Journal of the Linnean Society 140: 353-381. You can follow this LINK.