Evaluation of four artificial diets on demography parameters of Neoseiulus barkeri

Artificial diets (ADs) facilitate cost-effective mass rearing of many natural enemies. A life table analysis was conducted to compare the performance of Neoseiulus barkeri Hughes reared on four ADs and its prey, Tetranychus urticae Koch and Aleuroglyphus ovatus (Troupeau). The ADs were enriched with Bombyx mori (L.) hemolymph (AD1), Artemia franciscana Kellogg cysts and B. mori hemolymph (AD2), A. franciscana cysts and Corcyra cephalonica (Stainton) eggs (AD3), and A. franciscana cysts and Musca domestica L. larvae (AD4). Although N. barkeri reared on the four ADs all survived to adults, they had significantly longer life cycles and lower fecundity than those reared on T. urticae and A. ovatus. N. barkeri reared on AD2 and AD3 had a significantly higher r value, and shorter mean generation time than those reared on AD1 and AD4. Among the four ADs, N. barkeri fecundity was the highest on AD3 and oviposition period was the shortest on AD2. Measurement of the nutrient compositions of T. urticae, A. ovatus and AD3 showed that saccharide content in AD3 was highest, while the total amino acids content in T. urticae and A. ovatus were 9.1% and 19.3% higher than that in AD3. Among the 33 detected fatty acids (FA), AD3 was highest in saturated and monounsaturated FA content, and in polyunsaturated FA between T. urticae and A. ovatus. These results may help improve the reproductive performance of N. barkeri on AD3, and optimized AD3 may be useful for mass rearing of this generalist predatory mites.