525 



RoDDA(T. E.). Spray-testing at Arataki. Summer Control of Woolly 

 Aphis. — J I. Agric, Wellington, N.Z., xv, no. 1, 20tli July 1917. 

 pp. 23-24. 



As a result of spraying tests with different compounds, consisting 

 chiefly of Black-leaf 40 in varying strengths or of resin-soda, the latter 

 substance Avas found to scorch foliage more or less wherever used. 

 The woolly aphis [Eriosotna lanigenmi] was killed by the spray 

 wherever it had touched it with any force, but w^here this had not 

 occurred, the insects were still active. Black-leaf 40 appeared to have 

 greater penetrating power than resin-soda, probably owing to the 

 soft-soap added to the mixture. Resin-soda proved the cheaper 

 mixture, but takes a considerable time to prepare. 



Miller (D.). The Makerua and Moutoa Flax Areas in Relation to 

 Larval Attack. — Jl. Agric, Wellington, N.Z., xv, no. 1, 20th July 

 1917, pp. 25-29. 



This paper contains notes supplementing a previous article [see this 

 Revieiv, Ser. A, v, p. 453]. The topography of the Makerua and 

 Moutoa flax areas on the Manawatu River is described in detail. 

 On certain areas that have been overdrained there is a good growth of 

 New Zealand flax [Phormium tencix], but owing to the comparative 

 dryness produced by draining, the conditions are exceptionally favour- 

 able for the propagation of the caterpillars. Apparently more leaf- 

 tubes form under these conditions than where there is a moderate 

 amount of moisture. If moisture affects the age of the leaf, the 

 advantage of not having the swamps over-dry would be twofold ; there 

 would be more leaf at the time of cutting and less larval attack owing 

 to the lack of leaf-tube shelters. In moister localities fewer leaf-tubes 

 appear and larval attacks cause no aiDpreciable damage. 



Recent investigations have shown that the larvae of the flax-grub 

 [Xanthorhoe praefectata] winter in the soil, indicating the possibility 

 that winter flooding will prove an effective method of control. The 

 ground should be flooded just before pupation. Investigations are 

 being made to determine the minimum saturation of soil necessary to 

 kill the larvae. The flax-grubs first appeared as a bad infestation 

 where flax was being milled along the river bank just after draining, 

 in 1902. As a result, 11 tons of leaf were required to produce 1 ton 

 of fibre, in place of the normal 8 tons. On the east side of the river 

 the grub did not appear until eight years after draining, becoming 

 serious in 1910 and 1911, and gradually decreasing in numbers until 

 the present time. 



Orchard-Spraying Experiments in the Stoke District. — Jl. Agric, 

 Wellington, N.Z., xv, no. 1, 20th July 1917, pp. 30-36. 



This paper deals chiefly with spraying experiments against mildew 

 and other fungus diseases. Trials showed that a dormant spray of 

 hme-sulphur followed by the usual summer sprays was a satisfactory 

 remedy for red mite [Tetranychus] on apple trees. 



