Ecological characterisation of Steinernema australe (Panagrolaimomorpha: Steinernematidae) an entomopathogenic nematode from Chile

摘要

This paper reports on studies of a recently described species of entomopathogenic nematode, Steinernema australe, from Chile. Under laboratory conditions S. australe had a fast life-cycle, with new infective juveniles (IJ) observed after 6 d at 20 degrees C; however, adults and non-infective juveniles also emerged from cadavers and migrated away. The thermal and moisture profiles for infectivity were wide and significant infection occurred at cool, humid conditions, 7 degrees C and 15.8% moisture content (MC). Five days at ca - 1 degrees C had no effect on IJ survival, but subsequent host infection was substantially reduced, a possible chilling-injury or phase-switching of the symbiotic bacteria. Steinernema australe infected a wide range of insect pests from Chile, including mobile and sedentary hosts, appearing most effective against Lepidoptera. No nictating or jumping behaviour of IJ was observed.