108 DESTRUCTIVE INSECTS OF VICTORIA: 



MORDIALLOC, 1ST FEB., 1908. 



" On the 4th July last, I proceeded to Leongatha to investigate 

 the ravages caused by the grass caterpillars (Oncoptera intricata) 

 commonly known throughout South Gippsland as " Take-all." I 

 selected Mr. Thomas Crighton's property on which to carry out 

 experiments, as having suffered more from the pest than any other in 

 the district. Ploughing or scarifying the land as deeply as possible 

 so as to expose the caterpillars, which live in holes of from 12 to 18 

 inches deep, to insectivorous birds, would have been the simplest 

 method of eradicating the pest; but the rough nature of the affected 

 land, covered as it was with stumps and logs, prevented this. I 

 determined, therefore, to try top-dressing small areas with various 

 chemicals, which, while being fatal to insect life, would also act as a 

 manure for the soil. I marked off five plots of a square chain each 

 and top-dressed them respectively, at the rate of 56 Ibs. per acre, 

 with the following chemicals : Chloride of Potash, Sulphate of 

 Ammonia, Sulphate of Iron, Gypsum, and Quicklime. 



No result was apparant immediately; but a fortnight later, just 

 after a heavy fall of rain, which washed all the chemicals into the 

 sub-soil, I closely examined the plots. Upon that top-dressed with 

 the Potash Chloride I noticed a marked diminution of the pest. 

 The others were less effective in the following order : Sulphate of 

 Iron, Gypsum, Quicklime, and Sulphate of Ammonia. 



The caterpillars feed at night, being rarely or never found out of 

 their holes during the day. Their favorite food appears to be 

 cocksfoot grass ; they eat this above and below the ground. (And 

 unfortunately this is the grass most generally cultivated throughout 

 South Gippsland.) They frequent only the hills; on the flats or 

 places where water would lodge in a wet season they are not to be 

 seen at all. These facts tend to prove that they would not be 

 troublesome in a wet season." 



