Effect of cold storage on survival and parasitic activity ofHetero Rhabditis SP.

Heterorhabditis sp. (HW79) was stored in its culture substrate in Erlenmeyer flasks at a temperature of 6,0±0,4°C. Surviving infective juveniles were counted after 1, 22, 42 and 63 days of storage respectively. No significant decrease in surviving juveniles was found even after 63 days, nor was there any increase in numbers of dead juveniles after this same time. No reduction in parasitic activity againstO. sulcatus-larvae could be observed of juveniles stored at 6°C for up to 66 days. These experiments demonstrate thatHeterorhabditis sp. survives well under the mentioned conditions and fully maintains its infectivity. This is an important aspect in planning mass production of nematodes for commercialization.