Entomology definition of Diurnal September 7, 2014 Raj Entomology Dictionary 0 Please Like Us!!! DesiGoogly.com > Education News > Entomology Dictionary > Entomology definition of Diurnal Entomology definition of Diurnal: such insects as are active or habitually fly by day only. Diurnal Entomology explanationDiurnal Entomology meaningEntomology Diurnal definitionReviews & Comments