TO Dec. T9T0.] Slugs a7id Snails. ■ 807' 



SLUGS AND SNAILS. 



Alfred J. Ewarf, D.Sc, Ph.D., F.L.S., Government Bofanisf. 



It is, perhaps, hardly necessary to mention the amount of damage that 

 slugs and snails may do, especially on moist, heavy ground and among 

 young seedlings. It is curious to note how such plants as peas, broad 

 beans, beet, parsnips and parsley, are usually left untouched, whereas 

 Aoung lettuce, tomatoes, turnips, cabbages, cauliflowers and even carrots 

 often suffer severely and may be destroyed in a single night. It can 

 hardh' be due to die presence of anything unpleasant in the flavour of the 

 leaf or to any peculiarity of a particular group of plants, since the first 

 leaves of the French bean are often badly attacked. It mav be dependent 

 upon the rapidity with which the outt-r skin of the i)lant hardens or upon 

 its developing special protfcii\e hairs, as in many weeds and in the tomato 

 when bevond the seedling stage. 



Two methods often employed of warding off their attacks are by the 

 u.se of lime, wood ashes, .Vc. The effect of these rarely lasts for more 

 than a day or two. and any heavy shower of rain renders them immediately 

 u.seless. It may therefore be of interest to record a method which I found 

 to be most effecti\"e in preventing their ravages, and which is at the same 

 time very cheap and easily applied, so much so. that it mav prove useful 

 on a larger scale than in gardens. It is, for instance, much cheaper 

 than the u.se of tobacco powder and has not the danger attaching to the 

 use of metallic poisons, while it is, at the same time, much more effective 

 and permanent in its action than the use of salt or sand, and does not 

 involve the labour needed to catch slugs and snails at night or capture 

 them Dy means of calibage leaves, &c. 



The method is, in brief, to add one or two large tea-cups of phenyle 

 to ten or twenty cups of water, and use the mixture to moisten a bucket 

 of sawdust. The sawdust is then spread round the rows of plants to be 

 protected, or around single plants ; if the area enclosed is a large one, it is 

 also sprinkled on the surface of the soil. The protective action is remark- 

 able. It persists even after a hea\ y rain if the sawdust is not wa.shed 

 away and it lasts for a considerable time. During wet weather a stronger 

 solution can be emploved, since the phenyle slowly washes out of the 

 sawdust. Xo iniurious action is exercised on the plants nor upon the soil 

 as the sawdust slowly works into it. The effect of depri\ing the animals 

 of their food is to cause a marked decrease in their numbers, c]uite apart 

 from any poisonous action. The labour and cost involved are exceedingly 

 small — a bag of sawdust at is., allowing 6d. for carriage, and is. worth 

 of phenyle at 3s. 6d. per gallon will he sufficient for a fairly large garden. 



The method is particulary effective and useful for protecting young 

 tomato plants, which, in the young seedling condition, are often destroyed 

 by slugs or snails when planted out, liy being eaten at the ba.se near the 

 ground. As .soon as the epidermis or skin of the plant thickens, and 

 acquires its proper hairy covering, the plants are immune to their attacks, 

 whereas such plants as cabbages, &c., are liable to attack so long as the 

 weather is moist and hence need longer protection. 



Mr French (/ourna/. July, 1906). mentions the use of carbolized saw- 

 dust. The carbolic acid, however, washes out more rapidly than the 

 phenvle. and is hence less iiermanent in its action. 



