Effects of hanging density of Clanis bilineata eggs on the larval growth and development of this species and on soybean production
Author of the article:LI Xiao-Feng；GUO Ming-Ming；LI Da-Wei；DENG Pan；LI Jun-Ling；CHEN Feng
Author's Workplace：Institute of Lianyungang Agricultural Science of Xuhuai Area of Jiangsu, Lianyungang Academy of Agricultural Science, Lianyungang 222000, China; Institute of Leisure Agriculture, Jiangsu Academy of Agricultural Science, Nanjing 210000, China; Yuntai Branch of Jiangsu Provincial Agricultural Reclamation and Development Corporation, Lianyungang 222063, China
Key Words：Clanis bilineata; hanging density of eggs; larval growth and development; production
Abstract：
[Objectives] To compare the effects of different hanging densities of Clanis
bilineata eggs on larval development and soybean production in order to
determine the optimal hanging egg density for the artificial propagation of
this species. [Methods] At a
soybean planting density of 40 cm × 20 cm (row spacing × plant spacing), the
egg hanging density was experimentally set at 10, 20, 30, 40, 50, 60, 70 or 80
eggs/m2. Eggs were hung in 20 m2 plots with 3 replicate
plots for each of the 8 treatments, plus a control plot without eggs. The
developmental period, survival rate, body length, body weight and total yield
of larvae and soybeans, were compared between treatments and the control. [Results]
Larvae were harvested at 25 days of
age. The highest larval survival rate of 58.44% was recorded at a density of 30
eggs/m2, followed by egg densities of 10, 20 and 40 eggs/m2 (58.33%, 55.56% and 52.33%, respectively). Although there was no significant
difference in larval survival rate of these four treatments (P>0.05),
they were collectively significantly higher than those of the other four
treatments (P<0.05). The body length of larvae in the 30 eggs/m2 group was the same as that of larvae in the 10 eggs/m2 group (8.09
cm), and were collectively higher than those in the other 6 treatments. The
body weight of larvae in the 30 eggs/m2 group was 9.35 g, although
less than that in the 20 eggs/m2 (9.39 g) group, was not
significantly different (P>0.05). The highest larval yield of up to
158.00 g/m2 was recorded in the 30 eggs/m2 group,
followed by the 40 and 50 eggs/m2 groups which had larval yields
were 153.00 and 140.17 g/m2, respectively. There was no significant
difference in larval yield among these three treatments (P>0.05), but
they were collectively significantly higher than those of the other five
treatments (P<0.05). The soybean yield was 142.50 g/m2,
significantly lower than the control group yield of 210.33 g/m2 (P<0.05). [Conclusion] Larvae performed
well at a density of 30 eggs/m2, which is consistent with the market
demand. The results provide a theoretical basis and technical guidance for the
artificial culture of Clanis bilineata.