The Canadian Horticultun^ 



Floral Edition 



Vol. XXXVI [I 



PETERBORO, DECEMBER, 1915 



No. 12 



The Green Apple Bug on Apples and Pears 



W. H. Brittain, Provincial Entomologist for Nova Scotia 



FOR a number of years fruit growers 

 in the Annapolis Valley of Nova 

 Scotia have complained of the 

 non-bearing of certain varieties of 

 apples, especially the Nonpareil. Such 



The Green Apple Bug: and an injured pear. 



trees would bloom heavily every year, 

 but would invariably fail to set a crop 

 of anything but a few gnarled, twisted 

 apples. At the same time there came 

 frequent reports of pears that "grew 

 woody" and were covered with corky, 

 disfiguring scars. 



No one appears to have suspected 

 the connection between the trouble in 

 the apple and pears or that either of 

 them was due to an insect. Examina- 

 tion of affected orchards about blos- 

 soming time showed them to be swarm- 

 ing with small yellowish or green suck- 

 ing insects, which, in appearance re- 

 sembled long-legged plant lice. These 

 insects moved with extraordinary ra- 

 pidity and had a wonderful ability to 

 hide. They later developed wings and 

 became a delicate brownish insect about 

 one quarter of an inch long. This in- 

 sect proved to be an insect known as a 

 pear pest in New York State under the 

 name False Tarnished Plant Bug (Ly- 

 gus invitus). Lately it has gained an 



unenviable reputation in Nova Scotia 

 as the "Green Bug" or the "Green 

 Apple Bug." 



The pest is well distributed through 

 the main fruit producing centres of 

 Hants, Kings, Annapolis and Digby 

 counties, but, though the adult is a 

 fairly strong flier, it does not seem to 

 spread very fast. It is one of the most 

 serious pests in the Annapolis Valley. 

 In fact, where it once becomes estab- 

 lished there is no pest to compare with 

 it, either in amount of damage done oi- 

 in the difficulty of controlling it. That 

 such a pest should have gone so long 

 unnoticed is rather surprising and can 

 only be attributed to the very elusive 

 habits of the insect. 



Injury of the Oreen .\pple Bug: to apple.s. 



As far as we have determined the iii- 

 sect breeds only on the apple and pear. 

 It has been found feeding on plums in 

 the adult stage, but has not been known 

 to lay its eggs in that plant. When 

 shaken from the tree, the young in- 

 sects have been observed to feed on 

 various plants growing on the ground, 

 but when it reaches the winged state 

 it always- seeks the apple and pear tree 

 to feed and deposit its eggs. 



Life History. 



The eggs, which are laid beneath the 

 bark of the twigs, begin to hatch a few 

 days before the blossoms open. The 

 height of the emergence coincides with 



the opening of the blossoms and prac- 

 tically all are out by the time the last 

 blossoms fall. From thirty-one to 

 thirty-four days elapses from the time 

 the insect hatches until it gets its 

 wings. Soon after hatching the eggs 

 are laid, after which the adult insects 

 begin to die off, few remaining after a 

 month has passed. 



The young bugs are very active and 

 when disturbed run rapidly, hiding in 

 the axils of the leaves or any place 

 that affords concealment. When sud- 

 denly disturbed thej' frequently drop, 

 hut generally alight on another branch 

 liefore reaching the ground. When 

 ' forced to drop by heavy rains, winds, 

 sprays, etc., they may reascend the tree 

 or they may feed on the herbage at its 

 base until their wings are obtained, 

 when they will fly up into the trees 

 again. 



Experiments have shown that insects 

 that fall to the ground are capable of 

 feeding on, completing their transfor- 

 mations on timothy, red clover, couch 

 grass, dandelion and a great variety of 

 other plants. 



In feeding, the young insects prefer 

 the young leaves of apnle and pear, but 

 also puncture the tender twigs. Later 

 on they attack blossoms, but when the 

 fruit is set, -they feed on it to the ex- 

 clusion of other food. The later stages 

 will not feed on the leaves if other 

 food can be obtained. 



Injury of the Green .Vpple Bug to pears. 



