INVESTIGATIONS ON THE PRESENCE OF AN INFECTIOUS PROPORTION AMONGST POPULATIONS OF STEINERNEMA-FELTIAE (SITE-76 STRAIN) INFECTIVE STAGES

Experimental studies were conducted on the proportion of Steinernema f eltiae Filipjev (Site 76 strain) infective stages that infected Galler ia mellonella L larvae, in sand tube assays. A full statistical analys is of the sand assay tubes was also undertaken. The analysis showed th at the sand tubes were not a significant source of variation. Conseque ntly the observed behaviour of the infective stages was considered to be due to a biological effect. The study shows that the proportion of infective stages that became parasitic did not increase with increases in the density of applied infective stages, nor did the proportion in crease with an increase in the number of hosts. It is argued that thes e findings are consistent with the presence of a proportion of individ ual infective stages that are capable of causing infection.