larvae of two closely-related blowfly species of the genus Chrysomya (Diptera, Calliphoridae)

The third instar larvae of two closely-related blowfly species, Chrysomya megacephala (Fabricius) and Chrysomya regalis Robineau-Desvoidy (=marginalis Wiedemann) are described and illustrated, and a simple key is given to separate them. As with some other blowfly larvae, it was found that the structure of the spines was a most useful diagnostic feature. Although the natural ranges of these two species do not overlap to any extent, the recent introduction of Ch. megacephala into Africa (part of the range of Ch. regalis) makes it desirable to separate these two species in the larval stage.