SCIENTIFIC COMMITTEE, JULY 21. 



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caterpillars. The simplest way of effecting this is to fasten grease bands 

 round the stems, which the female moths are unable to cross. As this 

 might injure the tree if the grease came in contact with it, a strip of 

 grease-proof paper, 7 or 8 inches wide, and long enough to overlap an 

 inch or more, should be tied round the trees, say 3 three feet from the 

 ground, and fastened top and bottom with bast matting or soft string 

 that will not cut the paper. Over this should be tied a strip of calico 

 about the same width, also tied top and bottom ; this must be well 

 smeared with cart-grease, soft soap, and train-oil mixed, so that a soft 

 sticky compound is formed in which the moths' legs will be caught. 

 These bands should be put into position as early as the middle of October, 

 and kept in working order until well after Christmas. To do this the 

 bands should be re-greased every now and then, or whenever it is found 

 that the grease is losing its stickiness, or, as is sometimes the case, that 

 it is clogged up with the number of moths caught in it. Notwithstand- 

 ing these precautions, some of the females may find their way into the 

 young shoots. Some are no doubt carried by the males (who fly well) 

 when coupled, so that it is useful, when it can be carried out, to spray 

 the trees before the buds show any signs of opening with a caustic alkali 

 wash, made by dissolving 1 lb. of caustic soda in half a bucket of water, 

 add | lb. of pearlash, and stir until all is dissolved, then add enough soft 

 water to make 10 gallons, and finally stir in 10 oz. of soft soap which has 

 been melted in a little hot water. This mixture is very caustic, and must 

 not be allowed to touch the skin or clothes, or if it does it should be wiped 

 off as soon as possible. A still day should be chosen, so that the wind 

 will not blow it on to the operators ; this spraying should kill the eggs if 

 any are laid on the tree. To destroy the caterpillars the trees should be 

 sprayed, as soon as the fruit has set, with paraffin emulsion, or J lb. of 

 Paris-green and ^ lb. of lime mixed in 50 gallons of water. This mixture 

 must be kept well stirred, as the Paris-green is very heavy and soon sinks 

 to the bottom, in which case some of the mixture will be too weak to kill 

 the caterpillars, and the rest so strong that the foliage will be injured." 



Lilac Shoots and Frost.— Mr. Massee, V.M.H., showed a curious and • 

 important effect of frost on the leaves of the Lilac. The apex was frost- 

 bitten, then, after a thaw, the leaf became attacked by Botrytis cinerea, 

 which travelled down the region of the midrib and petiole, till it attacked 

 the terminal bud between the leaves. As thousands of flower buds were 

 thus destroyed in consequence of the late frost, great pecuniary loss 

 accrued to the growers for the flower markets. 



Scientific Committee, July 21, 1903. 



Dr. M. T. Masters, F.R.S., in the Chair, with eight members present, 

 and Mr. Hunt from New Zealand, visitor. 



Verbascum leaves diseased. — Dr. Cooke, V.M.H., reported on leaves 

 brought by Mr. Holmes : — " The white mould on the under surface of 

 the leaves of Verbascum is a well-known British species called Oidium 

 Balsamii. It occurs not only on leaves of Verbascum, but also on the 



