| The polyphagous predator Menochilus sexmaculata (Fabricius) (Coleoptera: Coccinellidae) is widely distributed and has a promising prospect in exploitation and utilization as potential biological control agent with its long life, eating prowess and high fecundity. Mass rearing of M. sexmaculata is of great importance to accelerate the industrialization of predatory natural enemy insect and pesticide reduction. Extensive studies have been done focused on its biology and ecology at home and abroad, but there were still no cost-effective artificial diets designed for mass propagation. In this present experiments, the composition of natural prey——Aphis craccivora (Koch) was analyzed and then artificial diets of M. sexmaculata was designed using animal or insect protein as the exogenous protein according to the results. Durations of different development stages, mortality, newly emerged adult’s weight and fecundity of M. sexmaculatawere considered to evaluate the value of the diets. In addition, suitable laboratory conditions, preparation formulations and preservatives were screened out. The main results were as follows:1. The growth and development of M. sexmaculata were compared at different environmental conditions. The results showed that 29℃,65% RH and photoperiods of L:D=18:6 was most suitable. Temperature was the main factors that affected the larval development rate, and photoperiods influenced the newly emerged adult’s weight, while high humidity caused some larve death.2. Oviposition period of M. sexmaculata lasted 68.43 d with 2011.00 eggs laid. Egg hatching rate was more than 86% within the first 40 days of oviposition period, then remained stable at about 60%.3. The impacts of different preservatives with different proportion composition of Nisin, Potassium sorbate, Sodium Methylp-hydroxybenzote and Sodium Ethyl p-hydroxybenzote on the development of larve were determined, the results showed that 0.02% Nisin+0.04% Potassium sorbate was the best. Two preparation formulations (liquid and gelatin) were compared for the development of larve and adult obtained rate, and the gelatin type was indentified as the best form of artificial diet.4. The contents of water, amino acid, fatty acid and mineral elements of A. craccivora were analyzed to clarify the nutrient requirements of M. sexmaculata. The results showed that the highest content was water; the following were protein and fat. In addition, N, P and K were the main mineral elements. It also revealed that the amino acid, fatty acid and mineral elements composition of A. craccivora was unique to some extent compared with other insects.5. Based on the nutrition constituent of A. craccivora, two feasible artificial diets were formulated with insect protein and animal protein, and then the rearing effect evaluation was conducted according to the development duration, larve mortality, newly emerged adult’s weight, fecundity and adult longevity. The results showed that M. sexmaculata can completed the whole generation development and laid a small number of eggs fed on both of the two diets AD1 and AD2. The adult obtained rate was 29.32% and 83.05%, the egg number per female was 24.53 and 142.46, and the adult longevity was 23.10 and 34.58 days, respectively. However, the rearing results of artificial diets were no better than the control group, thus the fumulas need to be optimized further. |
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