239 



ground. If thoroughly wetted they die, but if only >« lightly wetted 

 they recover and crawl up the bush again. It is therefore advisable 

 to follow the first spraying with a second treatment of the ground 

 underneath the bushes. This fluid is only intended to replace lead 

 arsenate against this pest when there is danger of poisoning the fruit. 

 The raspberry and loganberry beetle [Bijturus tomentosus] has been 

 found very difficult to control. The usual method has been to shake 

 the canes in the spring, when the beetle appears, over tarred sheets or 

 into pans covered with tree grease. This is useless, as the beetles 

 can only be dislodged by picking them out. A trial with nicotine- 

 paraffin emulsion showed that while the insects that were thoroughly 

 wetted were killed, those slightly wetted simply moved elsewhere. It 

 was therefore found necessary to carry out a preliminary spraying 

 to draw the beetles into the open ; paraffin emulsion alone was suffi- 

 cient to do this. After five minutes this was followed by a second 

 spray with nicotine-paraffin emulsion. This double spraying was done 

 three times, once a week, and was then stopped for fear of scorching the 

 leaves. The results were satisfactory ; no damage was apparent to 

 the flowers or the set of the fruit. Fungicides containing salts of 

 ammonium, potassium or sodium may be added to this spray, but 

 not lime-sulphur, Bordeaux or Burgundy mixtures. 



It is noted that though nicotine itself is safe to use on fruit that 

 will shortly be eaten, nicotine sulphate is not volatile and remains 

 on the fruit for a considerable time. 



Mally (C. W.). Natural Enemies of the Argentine Ant, Iridomyrmex 

 humilis, Mayr. >S. African Jl. Sci., Cape Town, xiv, no. 5, 

 December 1917, pp. 245-247. [Received 2nd April 1918.] 



Iridomyrmex hiouilis (Argentine ant), of which a full account has 

 already appeared [see this Review, Ser. A, i, p. 325], is a serious insect 

 pest in S. Africa, where it is practically free from natural enemies. 

 The fact that it is not regarded as a serious pest in its native country 

 of S. America, seems to point to the existence there of other species 

 ■of ants, the absence of one or more of which in certain i^arts would 

 account for its greater abundance in those districts [see this Review, 

 Ser. A, ii, p. 252]. Although practically immune from attack, this 

 ant is very aggressive, no other species of ant except an occasional 

 colony of Dorylus helvolus having been found at the Cape in areas 

 infested by it. In view of the difference in behaviour of this ant in 

 •countries where it is native and introduced, efforts should be made 

 to arrive at the facts of the case, so that the introduction of controlling 

 agents may be undertaken, should this be deemed advisable. 



Jack (R. W.). The Maize Beetle {Heleronychus mashunus, Pering.). — 

 Rhodewi Agric. J l, Salisbury, xv, no. 1, February 1918, pp. 10-15, 

 2 plates. 



Heteronychus mashumis (maize beetle) has caused considerable loss 

 to maize growers in various parts of Mashonaland and Matabeleland 

 for some years past. The beetles become active with the first heavy 



