Comparison of two rejuvenation methods on the virulence, fecundity and viability of Heterorhabditis megidis and Steinernema felitiae
Author of the article:DI Bin1, 2** QIAN Xiu-Juan LI Yu-Yu LIU Chang-Zhong
Author's Workplace:College of Plant Protection, Gansu Agricultural University, Biological Control Laboratory of Crop Diseases and Pests of Gansu Province, Lanzhou 730070, China; College of Plant Science and Technology, Huazhong Agricultural University, Insect Ecology Laboratory, Wuhan 430070, China; People᾽s Government of Manlu Township Linxia County, Linxia 731805, China
Key Words:entomopathogenic nematodes; rejuvenation method; pathogenicity; mortality rate
Abstract:
[Objectives] To investigate the effects of different
rejuvenation methods on the pathogenicity and fecundity of the entomopathogenic
nematodes Heterorhabditis megidis 0627M and Steinernema felitiae 0619HT. [Methods] The
pathogenicity, fecundity and mortality of H. megidis 0627M and S.
felitiae 0619HT with respect to two different host species Bradysia Odoriphaga Yang et Zhang and Galleria
mellonella was measured and compared. Changes in host behavior, body color
and time to death of both species were also observed. [Results] Different methods of rejuvenation had
different effects on nematode survival. Mortality of both strains was very low
when they had been stored for a short time (10 d) but increased with increased
duration of storage. Mortality of S.
felitiae 0619HT was higher, but not significantly so, than that of H. megidis 0627M. The pathogenicity of
both H. megidis 0627M and S. felitiae 0619HT to Mellonella mellonella was 100% after 40 h, and the infection rate was 5.67% and 2.33%, respectively.
The fecundity of H. megidis 0627M was
1.461 3×105 individuals/g whereas that of S. felitiae 0619HT was 2.395 2×105 individuals/g,
respectively, higher than that of S. mellonella. [Conclusion] It is
preferable to reinvigorate H. megidis 0627M and S. felitiae 0619HT by
reinvigorating their hosts, which significantly increased the fecundity,
pathogenicity and infection rates of both
species.