Ovarian development and pteridine accumulation for age determination in the blowfly Lucilia sericata

The patterns of ovarian development and pteridine accumulation in the blowfly Lucilia sericata Meigen are described with reference to age, temperature and fly size. Formulae are presented which allow measurements of egg follicle length and pteridine fluorescence to be related to chronological age. The limitations associated with the two methods of age determination are considered. It is concluded that for L. sericata females, the techniques would be of maximal value if used in combination, with pteridine fluorescence levels being used to identify the broad age-range and the likely ovarian cycle and more exact estimates within this range obtained by ovarian dissection.