440 



Insect, Fungus, and other Pests. [sept., 



(Kent) specimens of rose leaves were received infested with 

 Rose Rust (Phragmidium subcorticatum, Winter), and an inquiry 

 as to the best method of combating this disease was received 

 from King's Lynn. The orange-coloured patches observed in 

 summer give place as the season advances to black spots, these 

 consisting of masses of resting spores. To prevent a recurrence 

 of the attack all affected leaves should be collected and burned 

 in the autumn. If rust spots appear on the wood, the patches 

 should be treated, as soon as noticed, with a solution consisting 

 of equal parts of methylated spirit and water. This should be 

 carefully applied with a piece of sponge. In spring, when the 

 leaves are expanding, the bushes should be sprayed with a solu- 

 tion of potassium sulphide (i oz. to 3 gallons of water). 



Specimens from Tynemouth and Heathfleld were affected 

 with Rose Mildew (Sphaerotheca pannosa, Lev.), an exceedingly 

 common parasite on almost all kinds of roses. This mildew 

 may be kept in check by spraying the bushes with a very 

 dilute solution of sulphuric acid, 1 oz. in 5 gallons of water. 

 Diseased leaves should be collected and burned in the autumn. 



Oak and clematis specimens from Heathfleld were attacked 

 by other mildews of the same family as 5. pannosa. 



Mildewed Oak Leaves. — Specimens of oak leaves from 

 Exbourne (Devon) were covered with a so-called " white 

 efflorescence," due to the presence of one of the Erysiphacece 

 or mildew fungi. The exact species could not be determined 

 until the perithecia or autumn fruits developed, but the fungus 

 was in all probability a species of Microsphaera. The mildew 

 is exceedingly abundant this season in many parts of the South 

 of England. 



" Shot-Hole Fungus." — Peach leaves from Ryde were injured 

 by the " shot-hole fungus," Cercospora circumscissa, Sacc. 

 This well-known pest attacks the leaves of peach, apricot, 

 cherry, almond and nectarine. Small circular patches of the 

 leaf, bearing conidia on one or both surfaces, become dry, con- 

 tract and drop away, leaving a hole in the leaf. Numerous 

 holes are often present on a single leaf, giving it the appearance 

 of being riddled with small shot. Such diseased leaves : all 

 early in the season, before the formation of wood has been com- 

 pleted, and there is in consequence a poor crop the following 

 season. The young branches, and even the fruit of the peach, 



