Onset of immobilization in the slug Deroceras reticulatum (Muller) parasitized by the nematode Phasmarhabditis hermaprodita Schneider

摘要

The onset of immobilization in Deroceras reticulatum after drenching with inoculum of the nematode Phasmarhabditis hermaphrodita, at the recommended application rate was observed by infra-red time-lapse videorecording. Small slugs died within two daysof inoculation, but larger individuals were still observed active up to 10 days later, although their activity was markedly reduced after three days, and feeding and copulation ceased two days after treatment. In addition, parasitized slugs moved more slowly, with shorter and possibly more circuitous tracks. Parasitized slugs no longer confined the bulk of their activity to the night phase. There was a slight initial increase in activity in the first two days. The rapid immobilization suggests that the possibility of infected slugs transmitting the nematode to new sites is poor.