792 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Practically 50 per cent, of the fruit picked from unsprayed trees 

 with a good crop is injured by the codlin moth. As a rule spraying 

 tends to reduce the number of windfalls. Over 90 per cent, of the 

 windfalls from unsprayed trees are wormy. 



From the experiments one would be led to believe that during years 

 of small crops one may expect poor results from spraying, except, 

 perhaps, in the case where the spraying is done every week. When there 

 is a good crop, the trees sprayed oftenest in each series show the largest 

 percentage of sound fruit, while the trees receiving the least number of 

 sprayings show the smallest percentage of sound fruit. 



Early Apples appear to be less attacked by codlin moth caterpillars 

 than late varieties. — C. H. H. 



Squash Bug". By C. M. Weed and A. F. Conradi (U.S.A. Ayr. 



Exp. Stn., New Hampshire, Bull. 89; 2/1902; 2 figs.).— This bug 

 (Anasa tristis, De G.) attacks Squash, Cucumber, Pumpkin, Marrow, and 

 Melon. The best account of the insect is that given in the U.S. Div. of 

 Entomology, Bull. 19, by Mr. F. H. Chittenden, but the present paper 

 gives an account of the life-hiscory. The eggs are laid in clusters on the 

 leaves in June and July, and hatch out within a fortnight. The bugs 

 injure the leaves by sucking the sap, causing the leaves to dry up in 

 patches. The bug is one-brooded, and hibernates in the adult stage 

 among fallen leaves, &c. Its natural enemies in New Hampshire are a 

 two-winged fly, Trichopoda pennipes, perhaps toads (which, however, are 

 killed by the odour given off by the insects in a confined space), and a 

 fungus which could not be determined. The chief remedies recom- 

 mended are handpicking, clean, good culture, and spraying the ground 

 with kerosene as soon as the first frost kills the vines.— F. J. C. 



Sterilisation of Soil in Greenhouses for Fungous Diseases. 



By G. E. Stone (U.S.A. Exp. Stn. Mass.; Pub. Doc. 33; 1/1902; 

 pp. 74-85). — Sterilisation of the soil has been recommended for the 

 extermination of such fungous pests in the soil as cause drop in Lettuce, 

 &C, " timber-rot " in Cucumbers, Bhizoctonia, and Pythium De Bary- 

 a/n/um, and in part for stem-rot in Carnations ; nematode worms which 

 cause disease in Cucumbers, &c, aphis, red spider, and seeds of weeds 

 are also killed. 



Market growers are practising sterilisation of the soil in whole ranges 

 of greenhouses, and find that not only does it rid the soil of certain 

 disease germs, but also increases the crops. An experiment is detailed 

 showing that Lettuce gained 33 per cent, in weight when grown in 

 sterilised as compared with unsterilised soil, and 2*2 per cent, of this 

 increase was water. 



The sterilisation was effected either by hot water or by steam. The hot 

 water method requires the treatment of the soil previous to the putting 

 in of each crop, and only a few inches of surface soil are sufficiently 

 heated by this method to kill the mycelium of the drop fungus. 



The application of steam seems to be the most effective method of 

 sterilisation. The best means of applying the steam to the soil seems to 

 be through a system of perforated iron or galvanised-iron pipes. The 



