Comparison of biological characteristics of different geographical populations of Clanis bilineata

Author of the article:LI Xiao-Feng, CHEN Feng, DENG Pan, LI Jun-Ling, FAN Ji-Wei, GUO Ming-Ming

Author's Workplace：Lianyungang Academy of Agricultural Science, Institute of Lianyungang Agricultural Science of Xuhuai Area, Lianyungang 222000, China

Key Words：Clanis bilineata; population degradation; geographic population; hybrid; improved

Abstract：[Objectives]  To investigate the feasibility of improving the quality of captive-bred Clanis bilineata, an important edible insect in Lianyungang city and surrounding areas, by crossing individuals from this population with those from wild populations from different geographical areas. [Methods]  The size, pupation rate, emergence rate, pupal period and adult female lifespan between the captive-bred Jiangsu and wild Henan and Hubei populations collected in the field were compared. Adults from the Henan and Hubei populations were then crossed with those from the captive Jiangsu population by combining individuals from these populations at a 1: 1 sex ratio and allowing them to mate. After mating, the number of eggs laid by females, the hatching rate of eggs and the survival rate of larvae in each instar from each potential cross were compared. [Results]  The Henan and Hubei populations were superior to the Jiangsu population in all measured parameters. The Hubei population had the longest larval, pupal and adult female body lengths (7.59, 5.19 and 5.16 cm, respectively), and the Henan population had the longest adult male body length (4.44 cm). The Henan population also had the heaviest larvae and adult females (8.25 g and 3.52 g, respectively) and the Hubei population had the heaviest pupae and adult males (5.23 g and 2.23 g, respectively). The pupation rates of the Hubei, Henan and Jiangsu populations were 98.89%, 94.44% and 85.56%, respectively, and their eclosion rates were 94.44%, 97.78% and 97.78%, respectively. The progeny of Jiangsu ♀× Jiangsu ♂ pairs were the lowest among the 7 potential pairings. The progeny of Henan ♀× Jiangsu ♂ pairs had the highest female fecundity and hatching rate (139.67 and 90.67%, respectively). The survival rate of larvae decreased with instar irrespective of parentage. The progeny of Henan ♀× Jiangsu ♂ pairs had the highest 5th instar larval survival rate (74.67%), followed by the progeny of Hubei ♀× Jiangsu ♂ pairs (70.67%). The 5th instar larval survival rate of the former was significantly higher than that of the latter (P<0.05), and both were significantly higher than those of the other 5 crosses (P<0.05). [Conclusion]  Crossing Henan ♀ with Jiangsu ♂ can significantly increase the number of eggs laid by females, the larval hatching rate and the larval survival rate of each instar, thereby improving the quality of the captive Jiangsu population.