Effect of recycling temperature on the infectivity of entomopathogenic nematodes

Four strains of entomopathogenic nematodes were recycled in vivo for 2 years at temperatures ranging from 10 to 25 degrees C before the infectivity of their juveniles was compared. Infectivity was examined by measuring LC50 values for Galleria mellonella larvae at bioassay temperatures ranging from 5 to 25 degrees C. Of the 4 strains examined, only the Umea and NF strains of Steinernema feltiae that had been recycled at 10 degrees C infected and killed the insects at a bioassay temperature of 5 degrees C. The S. carpocapsae All and S. riobravis [Steinernema riobravae] TX strains were infective at 10 degrees C only when the recycling temperature was <=20 degrees C. The infectivity of the 2 strains of S. feltiae at 10 or 15 degrees C was compromised by propagating them at higher temperatures (20-25 degrees C). The Umea strain of S. feltiae displayed an impaired capacity to infect hosts at higher temperatures (20-25 degrees C) when recycled at lower (<= 15 degrees C) temperatures. The capacity of these nematodes to adjust to different recycling temperatures is discussed in relation to their infectivity in different field situations..RE: 17 ref.; SC: VE; CA; PE; 0T; 0E; 7ESource type: Electronic(1