52 



the distinguishing features between the injuries caused by 

 Sawfly and those due to Codling Moth. The Sawfiy ]arva 

 enters through the side of the apple and eats out a large 

 irregular cavity. The Codling Moth larva enters through the 

 *' eye " and tunnels down through the core, feeding mainly 

 on that portion of the apple ; it then mines a hole to the exterior 

 through the side of the fruit. The large irregular cavity is, 

 therefore, characteristic of the Sawfly, while the tunnel down 

 the core is usually the work of the Codling Moth. A further 

 form of injury attributed to the Sawfly consists in curious 

 ribbon-like scars sometimes found on the skin of the apple. 

 These scars are said to be made by the Sawfly larvae in their 

 efforts to bite a way in through the skin. 



Methods of Control. No practical measures for the 



control of this insect have yet been discovered. Spraying with 

 lead arsenate or Paris green have been tried without success, 

 the failure being probably due to the fact that the larva enters 

 through the side of the fruitlet and not through the " eye." 

 In the case of the Codling Moth sufficient poison is retained in 

 the eye to poison the young larva. Deterrent sprays against 

 the adult Sawfly have not proved of much use. The measures 

 which have been found of service are as follows, but they 

 are suited to small gardens rather than to fruit-growing on a 

 commercial scale: 



(1) All attacked fruits should be picked off the tree and 

 destroyed before the larvae have left them. 



J2) Poultry allowed to run under the trees during June 

 1 destroy the larvae as they go to the soil to pupate. 

 (3) By thoroughly working the soil under attacked trees 

 some of the pupae may be exposed to the attacks of birds while 

 others may be injured in the process or prevented from 

 emerging. 



BARK BEETLES AND SHOT BORERS. 



Fruit trees such as apples and plums frequently suffer from 

 the attacks of beetles which bore into their trunks, branches 

 and twigs, causing in the case of serious infestations the death 

 of part of or even the whole of the tree. The most common 

 species is the Bark Beetle (Scolytus rugulosus), but the Shot 

 Borer Beetles (Xyleborns dispar and X. saxeseni), though less 

 common, cause a more serious form of injury. 



I. BARK BEETLES (Scolytus rugulosus, Eatz.), 



Trees Attacked and Nature of Damage. The fruit tree 



most often damn^ed is the plum, but the beetles are also found 



on apple, pear, cherry, apricot, peach and quince, and among 



wild plants on Imwthoni, bird cherry and mountain ash. In 



