Growth energetics in relation to temperature for larvae of four species of necrophagous flies (Diptera: Calliphoridae)

The growth characteristics of the larvae of the major members of a necrophagous fly guild in Tasmania (Lucilia cuprina, Calliphora stygia, Calliphora vicina and Calliphora hilli) were measured to assess their competitive ability. The measurements were made at temperatures between 10 and 45°C, to cover the range of temperatures that would be encountered by larvae in carrion or myiasis under field conditions. The characteristics measured were net production and respiration. The indices K2i (instantaneous growth efficiency), K2c (cumulated growth efficiency) and Mi (instantaneous cost of maintenance) were calculated. Generally K2c and K2i are highest and Mi lowest at 25°C for all the species. A sinusoidal response in K2c, K2i and Mi against temperature is seen for L. cuprina, C. stygia and C. vicina. This response is‘cold’adapted in the Calliphora species and‘warm’adapted in L. cuprina. Egg size, egg caloric density and the energy content of the eggs are discussed in relation to the‘fitness’and reproductive strategies of the four species. The thermal tolerance range of L. cuprina determined here suggests that carrion may provide a significant number of this fly particularly in areas where Chrysomya spp. do not occur, and in large carcasses where temperatures are elevated.