EXPERIMENT STATION BULLETINS. 303 



crushing the living, yellowish lice beneath the scales. " During winter the 

 insect is to be found in the half- grown or nearly full-grown condition. The 

 young begin to hatch and to crawl from under the female scales shortly 

 after the trees leaf out, and from this time through the summer there is a 

 constant succession of generations." 



The species is known to feed on such trees as the plum, cherry, pear, 

 apple, peach, quince, and rose, and is sure death to a tree within a very few 

 years. Its spread into an orchard and into neighboring orchards is accomp- 

 lished before people are aware of its presence and then it is very difficult 

 to exterminate. 



Remedies. — Mr. J. B. Smith of New Jersey has probably had a wider 

 experience in treating this scale in the east than any other person and the 

 following recommendations are condensed from his own: 



1. The treatment should be made in the winter or while the trees are 

 dormant, if possible, as the remedies can be used stronger and made more 

 effectual without injury to the tree at this time. 



2. If there is loose bark on the tree, under which the scales can hide, 

 scrape it off. If the trees are large and difficult to reach, prune them back 

 all they will bear and cart the brush away from the orchard. 



3. Scrub or spray the tree thoroughly in every part with either a satu- 

 rated solution of caustic potash or half and half of commercial potash and 

 caustic soda, using about five quarts of water to each pound. This should 

 be applied only when the trees are dormant. At any other time of the year 

 whale oil soap, at the rate of two pounds to each gallon of water, should be 

 used. 



4. Follow the first application a month later by an application of kerosene 

 emulsion, nearly full strength, as given by the formulae under insecticidea 

 The emulsion at this strength will do the dormant trees no harm and ought 

 to kill every scale that escaped the potash solution. 



DISEASES OF THE CHERRY. 

 BROWN ROT [Oidium. fructigena, Kze. and Schm). 



The leaves, flowers, fruits, and sometimes the young stems of the cherry 

 are attacked by this disease. The injury to the leaves or stems is seldom 

 very severe, but, if the flowers or young fruits are attacked, the entire crop 

 may be lost. It is most troublesome when wet weather occurs at, or soon 

 after, the time of flowering. The germinating spores enter the tissues and 

 piercing the cells rob them of their contents. The germs of decay being 

 admitted, the so-called rot ensues. Whenever warm weather follows 

 periods of extended rainfall, we may look for the rot, and if the flowers or 

 small fruits are attacked we may expect that the fruit will be considerably 

 cut short. 



The brown rot can be distinguished from ordinary decay by the fact that 

 it produces immense numbers of yellowish-brown spores which appear in 

 large clusters, often covering the fruit or stem. The diseased fruits gradu- 

 ally shrivel and often hang for a long time upon the trees (Fig, 23a). 



In combatting this disease, it is particularly desirable that the early 

 spraying with copper sulphate solution should be thorough, that no spores 

 escape to spread the disease to the young leaves and flowers. As the dis- 



