575 



will check attacks. Immersion of the wood in water for some weeks 

 also prevents the attacks of Lyctids. It is hoped that the damage 

 done by these insects may be more simply obviated by the choice of 

 those varieties of timber that are immune frcm attack. 



L' Apparition du Doryphora de la Pomme de Terre [Leptinotarsa decem- 

 lineata, Say] en France. — Rev. Bot. app. & d'Agric. colon., Paris, 

 ii, Bull. 12, 3lst August 1922, pp. 430-434. 



This information has been largely drawn from a note by Dr. J. 

 Feytaud and from the work of Dr. P. Marchal, a good deal of it having 

 been already noticed from other sources [R.A.E., A, x, 536, 537]. 

 The history of previous introductions of this beetle into Europe 

 is sketched, and the legislation recently passed in France as a 

 result of its appearance is quoted. A general account of the beetle 

 and its life-history is given. The experiments of Feytaud and Monteil 

 have led to certain conclusions, which are outlined. Spraying should 

 be done under high pressure, and it is not sufficient to poison the leaves 

 only, as the larvae can survive on the stalks and stems, whence they 

 will reappear on the new growth. Both adults and larvae are repelled 

 by distasteful food and will leave it for neighbouring weeds on which 

 they subsist until fresh potato shoots have grown ; this is noticeable 

 when Bordeaux mixture alone is used, without any arsenical. The 

 addition of attractive substances, such as molasses, however, incites 

 more active feeding on the poisoned foliage ; this should be borne in 

 mind for future treatments. A dose of 5 : 1 ,000 of lead arsenate 

 obtained by the reaction of anhydrated sodium arsenate (2 : 1 ,000) 

 and of neutral lead acetate (1 : 1,000) is much less efficacious and 

 has much slower action against L. decemUneata than anhydrated 

 sodium arsenate (2:1,000) alone. Lead arsenate at this strength 

 is not efficacious, as the action of the poison is not sufficiently rapid to 

 destroy the mature larvae before their pupation, especially as they do 

 not feed much during this period. The dose must therefore be doubled 

 to about 1\ lb. per 100 gals., or 15 lb. of commercially prepared powder. 

 Strict watch is being kept for new centres of infestation, which continue 

 to appear in spite of all precautions, and meanwhile treatment with 

 arsenical sprays and other remedial measures are being rigorously 

 carried out. 



TiLLYARD (R. J). Progress of the Work of Breeding and Distribution 



of Aphelinus maJi in New Zealand.— A^Z. //. Agric, Wellington, 

 XXV, no. 1, 20th July 1922, pp. 31-34, 1 fig. 



In continuation of the work of colonising Aphelinus mali, Hald., 

 in New Zealand \R.A.E., A, ix, 534], special trees have been prepared 

 in the infested localities wherever possible for receiving the parasites, 

 and to be used as secondary distributing centres during the next 

 summer. They are enclosed "in a large cage covered with bird-proof 

 wire netting and are also covered with scrim on the roof and windward 

 side. They are kept unspraved so that the woolly aphis [Eriosoma 

 lanigeruni.'^Ua.usm.] may breed on them in sufficient numbers to allow 

 of a plentiful supply of A. mali being reared in the following summer. 

 A table records the'dates and numbers of each consignment of A. mali 

 sent out from the present distributing centre at the Cawthron 

 Institute, Nelson, showing a total of nearly 3,000, this being a great 

 advance on the previous year. 



