270 



This is to be expected, as at the higher altitudes the moths could not 

 emerge at such a time as November owing to the covering of snow. 

 Even were the flights to occur at the same time, the pupal stage 

 would still be shorter in the mountains, owing to the later spring 

 delaying pupation. Reports on C. brumota are very conflicting. In 

 the Zurich district, for instance, the author has never seen adults 

 between New Year and spring, nor has he observed pupation to be 

 prolonged until autumn. 



From the experiments described in this connection, it appeared 

 that the egg-stage, which lasts about 5^ months in the Zurich 

 district, takes longer in the mountains, but may be reduced to 

 about one-fifth if the eggs are subjected to a high temperature. The 

 larval stage, which averages six weeks near Zurich, is also greatly 

 reduced in length at artificially raised temperatures ; at 77° F. 

 only a fortnight is necessary. The pupal stage, usually lasting 

 about 5 months, could not he shortened in anything like the same 

 proportion. In one experiment only, in which the moths emerged 

 in mid-July, did this stage average 4| months. The removal of pupae 

 from the valleys to a point about 6,500 feet higher up, or to artificially 

 cooled chambers, repeatedly caused a distinct, though unimportant, 

 delay in the emergence of the adults. It is however probable that 

 pupation only lasts 3| months at the highest altitudes in Switzerland 

 where this moth occurs. These experiments show that the emergence 

 of the adults depends on the rate at which the pupae mature and is 

 not accelerated by the action of cold. 



Schneider- Orelli (0.). Die Frostspannerbekampfung im Fruhjahr. 



[The Control of Cheimalobia bi-umata in Spring.] — Schweiz. Zeitschr. 

 Obst- u. Weinbau, Fratienfeld, xxvi, no. 7, 31st March 1917, 

 pp. 97-101. 



If the banding is in comparatively good condition after the winter, 

 it should not be removed from fruit trees until May in order that the 

 larvae of Cheimatobia brumata that hatch from eggs deposited on the 

 trunk may be prevented from ascending. All that is necessary is 

 to remove a strip of the hardened upper layer of adhesive from f to | of 

 an inch Avide, or to place a strip of fresh material of this width over 

 the old band. As the newly hatched larvae are only 2 millimetres 

 long, they are held fast by very small quantities of adhesive. If the 

 bands are in such a condition as to be useless, or if they have have 

 been removed during the winter, it is advisable to scrub the trunk up 

 to the point where the banding had been applied w^th a 10-15 per 

 cent, solution of soft soap, with lime-sulphur mixture diluted with 

 three times its bulk of water, or wdth a 2 per cent, tobacco extract. 

 This must be done not later than early in April in order to kill the 

 eggs, and is cheaper than applying new bands. A 15 per cent, 

 strong milk of lime may also be used. This spring treatment is 

 useless in cases where banding has not been applied in the preceding 

 autumn. In the case of small trees neglect in banding may be remedied 

 to some extent by spraying wdth a home-made 2-3 per cent, soft-soap 

 solution. The spray must be a very fine one at high pressure if the 

 larvae are to be killed. 



