New Approaches For Extracting And Mass Rearing of Entomopathogenic Nematodes In Vivo

Abstract

The dual-purpose of spongy traps for extracting and storage of EPNs was validated in this investigation. The spongy traps proved to be the most efficient method for recovering IJs from the insect cadavers (Galleria mellonella) comparing with the traditional white traps. Also, the spongy trap kept the viability of IJs for prolonged time (12 weeks). Based on these results, duplications of insect cadavers in spongy traps will be rather encouraging for nematode mass production. A linked study was continued for detection an artificial diet for G. mellonella larvae. This step is necessary towards the mass production of EPNs in vivo. The recommended artificial media divided into two parts: the first part is supplemented with old beewax used for feeding 1st and 2nd instars of insect larvae. The second part is supplemented with paraffin oil used for feeding the other instars of insect larvae. The present results demonstrated that, the insect larvae could live and develop on this artificial diet. Moreover, both nematodes of Heterorhabditis bacteriophora (Hb) and Steinernema carocapcae (Sc) have proven to propagate perfectly in insects fed on the artificial media. Full death of all treated insects by Sc or Hb occurred (mortality=100%). The pathogenicity and reproduction of Hb nematodes produced from insect larvae fed on artificial diet gave initial population (Pi), final population (Pf), Rate of reproduction (Rr) and Efficiency of conversion (Ec) values superior than those fed on beewax checks at 100 IJs/insect larva. Similary, the pathogenicity and reproduction of Sc nematodes produced from insect larval fed on artificial diet were equivalent to or superior than those produced from insects fed on beewax in all inoculum levels. These new methods require minimal expertise and capital investments for extracting, storage and mass production of the beneficial Entomopathogenic nematodes (EPNs).