QUALITY OF THE ENTOMOPATHOGENIC NEMATODE STEINERNEMA-CARPOCAPSAE PRODUCED ON DIFFERENT MEDIA

The characteristics of morphometric (body length and width), biochemic al (fatty acid content), motility, and penetration rate of infective j uveniles of Steinernema carpocapsae Beijing strain reared on four diff erent culture media [e.g., plant protein medium (I), animal protein me dium (II), plant and animal protein medium (III), and in vivo culture (TV) were systematically compared in this research. The results showed that the average lengths of infective juveniles were 497.4 +/- 0.09, 514.3 +/- 0.08, 525.7 +/- 0.09, and 556.6 +/- 0.09 mu m, the average w idths were 24.9 +/- 0.006, 25.6 +/- 0.005, 26.1 +/- 0.006, and 27.9 +/ - 0.004 mu m, and the average dry weights per million infective juveni les were 49.2 a 2.2, 58.6 +/- 2.4, 59.6 +/- 1.8, and 80.7 +/- 1.7 mg c ultured by media I, II, III, and TV, respectively. The highest relativ e content of fatty acid of infective juveniles was obtained from mediu m TV at 15.4 +/- 1.2 x 10(5) mu V/s, and the lowest one was 6.76 +/- 0 .3 x 10(5) mu V/s from medium I and 11.8 +/- 0.2 x 10(5) and 13.7 +/- 0.3 x 10(5) mu V/s from media II and III, respectively. The numbers of nematodes that moved a vertical distance of 5 cm in sand column withi n 48 h were 24 +/- 3.6, 75 +/- 11.6, 69 +/- 9.7, and 92 +/- 13.2 and t he penetration rates into the Galleria larva within 24 h were 2.8 +/- 0.45, 6.0 +/- 1.14, 6.4 +/- 0.74, and 6.0 +/- 0.7% from media I to IV, respectively. The results indicated that the quality of entomopathoge nic nematode was influenced by the cultural medium component. The anim al protein, especially from insects which were presented in media II, III, and TV, has a strong positive effect on nematode quality. (C) 199 7 Academic Press.