Optimization the hatching and feeding of Protaetia brevitarsis larvae

Author of the article:BI Yong-Li1** LI Chun-Hui1 ZHANG Guang-Jie2,3 LI Ming1 MA De-Ying1***

Author's Workplace：1. Key Laboratory of the Pest Monitoring and Safety Control of Crops and Forests of the Xinjiang Uygur Autonomous Region, College of Agronomy, Xinjiang Agricultural University, Urumqi 830052, China; 2. Engineering Research Center of Edible and Medicinal Fungi, Ministry of Education, Jilin Agricultural University, Changchun 130118, China; 3. Manas County Golden Insect Biotechnology Co., Ltd., Changji 832205, China

Key Words：Protaetia brevitarsis; oyster mushroom spent substrate; compound feed; larval growth and development

Abstract：[Aim] To investigate the effects of mixed materials; Pleurotus ostreatus spent mushroom substrate, cow dung, and cotton straw, on the hatching, growth and development of Protaetia brevitarsis larvae, and also to determine the appropriate agricultural wastes and compound feed ratios for the optimal growth and development of 1st-instar larvae, thereby providing a basis for both the efficient, large-scale breeding of this species, and the efficient utilization of solid agricultural waste. [Methods] Treatments (M1-M4) were four different combinations of mushroom substrate, cow dung, and cotton straw, with the traditional cow dung-cotton straw combination (CK1) and pure Pleurotus ostreatus spent mushroom substrate (CK2) serving as the controls. The hatching rate, larval body length, body weight, survival rate, growth rate, feed utilization rate, feed conversion ratio, and internal juvenile hormone content of larvae in each treatment group were systematically measured and analyzed. [Results] Although there was no significant difference in hatching rate between the control and treatment groups, the M1 treatment (32% cow dung, 20% Pleurotus ostreatus spent mushroom substrate, 48% cotton straw) was superior to the other treatments in all other parameters measured. The larval body weight, obtained biomass, growth rate, and feed utilization rate of M1 (131%, 152%, 152%, and 67%, respectively) was significantly higher than that of both CK1 and CK2 (427%, 508%, 507%, and 623%, respectively) (P < 0.05). Treatment M4 (80% Pleurotus ostreatus spent mushroom substrate, 8% cow dung, 12% cotton straw) was the best in terms of promoting larval body length. Body length was 22.86% greater in this treatment group than in CK1, and 85.01% greater than in CK2 (P < 0.05). In addition, the juvenile hormone content of the M2 treatment group (24% cow dung, 40% Pleurotus ostreatus spent mushroom substrate, 36% cotton straw) was significantly higher (108.94% and 70.76%, respectively) than that of the CK1 and CK2 groups (P < 0.05). This was helpful for maintaining the stability of larval instars and also prolonged the transformation and treatment cycle of agricultural waste. [Conclusion] A combination of 32% cow dung, 20% Pleurotus ostreatus spent mushroom substrate, and 48% cotton straw can both promote the growth and development of P. brevitarsis larvae, and the transformation and utilization of cow dung and cotton straw waste.