Quality Control of Mass Rearing of Egg Parasitoids of Yellow Rice Stem Borer Scirpophaga Incertulas Walker

Abstract

The study was conducted to find out: suitability of eggs of Corcyra cephlalonica Stainton as a factitious host of S. incertulas egg parasitoids and techniques of parasitoid stock provision, serially conducted from February 2011 to December 2011. The researches were carried out in four laboratory experiments, consisting of the study of ultraviolet (UV) irradiation on C. cephalonica eggs; suitability of C. cephlalonica eggs as a factitious host of Telenomus rowani Gahan, Trichogramma japonicum Ashmead and Tetrastichus schoenobii Ferriere; storage method of C. cephalonica eggs; and storage method of parasitoids. The research design was suited to the research needs. The results showed that; The C. cephalonica eggs irradiated by the minimum of 28.48 minute 15 watt ultraviolet (UV) at a distance +15 cm between the lamp and the eggs could suppress the hatching eggs to zero (no emerged larvae). Among the three species of egg parasitoids of S. incertulas found in Jambi Province, only T. japonicum could be rearing on C. cephalonica eggs. The relationship between storage duration of C. cephalonica eggs irradiated by the 30 minutes 15 watts UV at 5oC and the emerged T. japonicum wasps was expressed by the equation of y = 31.04-1.151x, R²=0.865, P=0.000. The storage of T. japonicum pupae for six weeks at 5°C did not reduce the number of emerged T. japonicum wasps. The emerged wasps reduced significantly if the storage duration of T. japonicum pupae was increased to seven weeks or more.