28 DESTRUCTIVE INSECTS OF VICTORIA : 



Prevention and Remedies. 



On cultivated areas, cleanliness is the mam point in 

 preventing attacks by insects of this class, as when grass 

 or weeds are permitted to grow on headlands, these places 

 are harbours for insects of all kinds. They are also covers 

 for egg-laying, so that it will be seen that without clean 

 cultivation the chances of escape from these pests will be 

 considerably lessened. Trapping in places where stock is 

 not admitted is about the best method of destroying the 

 caterpillar. It is done by growing strips of such plants as 

 appear to be most relished by the grubs, and spraying the 

 same with either Paris green or arsenate of lead. 



In some cases, fungus parasites especially prove valuable 

 auxiliaries to the grower. Mr. E. Anderson, writing of the 

 larva of a common Victorian moth {Afina callisto), says — 

 ' They are kept in check by a parasitic fungus, whose 

 spores find a suitable germinating place in the bodies of 

 the caterpillars, eventually choking up their whole system 

 with a white corky substance, and, as the year is favourable 

 to the abundance of the Ajoina, seem equally favourable to 

 the spread of the fungus." There is no doubt that fungus 

 parasites help materially to keep certain of our insect pests 

 in check, and it is a common occurrence well known to 

 observers in the Victorian bush, to see dead grasshoppers 

 in large quantities fastened on to the tops of rushes or 

 other plants, and even on dead twigs. The bodies of these 

 are found to be empty and shrivelled, but without any 

 apparent cause, which, however, a powerful lens will at 

 once disclose. It is also no uncommon sight to see cater- 

 pillars hanging limp and decomposed from twigs ; the 

 rapid action of the bacteria soon causes the death of the 

 most robust caterpillars. The question of parasites as 

 aids to destruction is as yet in its infancy, but the subject 

 is a useful and interesting one, and should be closely 

 studied, especially by those engaged in rural pursuits. 



