126 DESTRUCTIVE INSECTS OF VICTORIA: 



October on peach trees. They were apparently eating 

 some of the peach aphis, but this did not last long, as 

 they commenced to attack pumpkins, marrows, etc., 

 about the end of October, and the raspberries later on. 

 These insects are peculiarly gregarious in their habits, 

 as they only associate while feeding and copulating; 

 and at no other time do they show any inclination to go 

 together. When a pumpkin, for instance, has been 

 singled out for attack, its leaves are invariably destroyed 

 one at a time. One of the beetles begins to eat the edge 

 of the leaf ; soon the beetle will be joined by another, and 

 so on. Then the insects may increase in numbers, 

 flying from all directions, and taking up positions on 

 the leaf alongside those which have commenced to feed. 

 They work outward from the centre in the form of a 

 semi-circle, and in a short space of time according to 

 the number attacking the leaf it will be destroyed, 

 nothing remaining but the stem and the hardened 

 tissues of the leaf. Another leaf is then attacked in a 

 similar way, and so on, until the plant is riddled (see 

 plate), the young leaves in the centre escaping until the 

 last. The beetles are more drowsy in the early morning 

 and evening ; and, if disturbed while feeding, some will fly 

 away, whilst others hide among the leaves and flowers ; 

 but at midday they are over-active, and, if feeding, they 

 fly away in different directions on being approached. 

 In order to combat this pest, I first used arsenate of 

 lead (Swift's), which was fairly successful, as I after- 

 wards found a number of the beetles dead on the ground. 

 I subsequently used the arsenate, but the beetles came 

 in such numbers that they devoured all the leaves on 

 which the poison had been placed. From this I 

 concluded that, to deal effectually with this pest, some 

 material should be put on the leaves to prevent the 

 beetles from attacking them. I found a strong solution 

 of quassia to be fairly good for the purpose, also phenyle, 

 and dusting the leaves with finely-powdered sulphur. ' ' 

 Field Inspector Pescott, of Bendigo, writes: "I beg 



