Biological and biochemical differences between in vitro‐ and in vivo‐reared Exorista larvarum

Abstract

AbstractQuantitative and qualitative parameters of Exorista larvarum (L.) (Diptera: Tachinidae) reared on two insect‐material‐free artificial media and in the factitious host Galleria mellonella L. (Lepidoptera: Pyralidae) were compared. Significantly higher puparial yields and weights were obtained in both a milk‐based and a veal homogenate‐based medium than in the factitious host. Longevity and parasitization rates were not different between the in vitro‐ and in vivo‐reared flies. Despite the greater puparial weight of the veal medium‐reared E. larvarum females, the number of eggs laid by these females on host larvae was not higher than that of females reared under the other two rearing conditions. Moreover, in a complementary experiment, with homogeneous puparial weights of milk medium‐ and host‐reared females, the former oviposited fewer eggs. Hence, puparial weight alone is not a reliable quality parameter for E. larvarum reared on artificial media. Lower amino acid content, with a deficiency in aromatic amino acids and an excess in proline, was found for in vitro third instar parasitoid larvae reared on both media compared to the in vivo‐reared ones. These results suggest a correlation between the amino acid deficiency and imbalance of medium‐reared larvae and the lower number of eggs laid by the females obtained.