ON PESTS GENERALLY. lilt 



Lichen is met with on orchard and other trees, particularly 

 those upon poor soils and upon which not much attention has 

 been bestowed. It is objectionable chiefly because of the 

 harbourage it affords to many very destructive species of insects. 

 Winter dressings of ordinary commercial potash and caustic soda 

 (in the proportion of ^lb. of each to 6gals. of water) is the best 

 remedy to apply, first having scraped the trunks, but taking care 

 not to penetrate the bark. The dressing recommended will not 

 only destroy the Lichen, but will kill many kinds of insects found 

 thereon. This must be used as a winter dressing only, and the 

 operator should wear thick gloves. In the case of Peach- and 

 Apricot-trees, which push their buds early, the greatest care 

 must be taken, as the mixture is likely to prove injurious to 

 forward buds. It should be applied hot. Bordeaux Mixture, 

 sprayed on in winter, may also be employed in the case of 

 Lichen-grown trees. Errors in cultivation" or poor soils must, of 

 course, be attended to, or the trees will be again speedily 

 attacked. 



Mildews. — By this name are popularly designated a number 

 of fungi affecting various plants and substances. Scientifically 

 the true Mildews are known as Erysiphece, to distinguish them 

 from the Peronosporecz. The chief characteristic is that the mycelium 

 is white, and is found on the outer surface of leaves, fruits, 

 and stems. Mildews appear year after year if measures are 

 not taken in summer to prevent the conidia from germinating. 

 They are tided over the winter by means of ascospores. Sulphur 

 in some form is the best fungicide with which to combat 

 Mildews, sulphide of potassium and flowers of sulphur both being 

 employed. The work must be thoroughly done, and often 

 repeated. Hot water should also be tried. 



Polyporus. — To this genus belong several species with which the 

 gardener, and especially the landscape gardener, and fruit cultivator, 

 should be acquainted. Many are very destructive, and occur on 

 a very large number of trees — P. sulphureus, for instance, whose 

 yellow sporophores are common upon Oak, Apple, Pear, and 

 many other trees. The spores gain access through a wound, the 

 internal parts of the tree are involved, the wood assuming 

 a reddish tint, and finally rotting ensues. The sporophores 

 should be removed and burned as soon as possible, otherwise 

 multitudes of spores will be released and disseminated. Trees 

 which are accidentally injured should at least have a dressing 

 of tar applied to the wounds. It is useless attempting to deal 

 with the mycelium. 



Another destructive species is P. hispidus, found upon fruit- 

 trees generally, as well as upon Ash, &c. The sporophores are 

 dark brown, and rough on the upper surface, and with smooth 

 yellowish pores. They are of large size, and are common 

 objects on the trunks of their host-plants. Like the preceding 



