1916 ENTOMOLOGICAL SOCIETY. 65 



Db. Glasgow: About the last of May or early in June, or whenever the 

 beetle becomes abundant to warrant treatment. 



The President: If there is no further discussion we will proceed to the 

 next gaper, which is of great interest, by Professor Brittain, on "Lygus vnvitus 

 and its control in 1915." 



THE GEEEN APPLE BUG {Lygus invitus Say.) IN NOVA SCOTIA. 

 ' W. H. Brittain^ Provincial Entomologist for Nova Scotia. 



History. 



For a number of years past certain fruit-growers in the Annapolis Valley have 

 complained of the non-bearing of their Nonpareil trees. These trees would 

 bloom heavily each year, but would never bear anything like a full crop, yielding^ 

 only a few gnarled apples; or, in many cases, none at all. This trouble was not 

 entirely confined to Nonpareils, but was more pronounced and by far the most 

 common in this variety. Others complained that their pears " grew woody " and 

 were covered with corky, disfiguring scars. This latter trouble was commonly 

 ascribed to lack of iron in the soil, and liberal applications of iron filings were 

 frequently applied to correct this condition. Driving nails or spikes into trees was 

 also practised. 



No one appears to have suspected that there was any connection between the 

 apple and pear trouble, or that either was caused by an insect. In June, 1914, the 

 writer visited an orchard consii^tin.c: of mature Nonpareils, Kibstons, Gravensteins, 

 Golden Eussets and several varieties of pears. The owner stated that the Non- 

 pareils had not had a crop for at least six years, and that the trouble was gradu- 

 ally spreading to the other varieties. Furthermore, the pears were so badly 

 affected that a number of them had been cut down. The affected trees were 

 swarming with the green nymphs of Lygus invitus, and it took very little observa- 

 tion to show that they were the culprits. Following this, many reports of similar 

 damage to apples and pears were followed up with a like result, and further in- 

 vestigations have only tended to confirm our early observations. 



Distribution and Spread. 



The pest seems to be well distributed throughout the fruit-growing centres 

 of Nova Scotia, including the counties of Hants, Kings, Annapolis and Digby. 

 It seems to be more widely distributed on the pears than on the apples, the phrase 

 " injury to pears only " occurring with considerable frequency in the reports of 

 the entomological inspectors. 



Though experiment has shown that the adults are capable of flying consider- 

 able distances, as a matter of fact, the pest spreads only slowly from orchard to 

 orchard. One orchard immediately across the road from a very heavily infested 

 one, showed few signs of injury. The amount of damage to pears does not seem to 

 vary much from year to year, but the injury to apples appears to be on the 

 increase in many localities and spreading from the more susceptible to the less 

 susceptible varieties. 



