8 BULLETIX 886, U. S. DEPARTMENT OF AGRICfLTtTKE. 



Oviposition was observed repeatedly and the following may be 

 given as a typical example of one of the more elaborate operations 

 attending the act: About an hour before sundown a beetle was ob- 

 served to take a horizontal position across the trunk of a young apple 

 tree, about 30 inches above the ground. She began at once to force 

 her j aws their full length into the tender bark. (PL II, C.) After 

 the jaws were inserted and withdrawn, the beetle moved sidewise up 

 the trunk for a short distance and again inserted them and thus 

 continued the operation until she had a straight line of pricks about 

 2 mm. apart. When the line was about 2 inches long she joined 

 several of the pricks together with a deeper furrow and then turned 

 around, as though on a pivot, and inserted the tip of her abdomen 

 into the opening. (PL II, D.) She then spent nine minutes in 

 forcing her ovipositor forward between the bark and wood, after 

 which she withdrew her ovipositor, reversed ends, moved across to 

 the other side of the opening and then consumed an equal period of 

 time in again inserting her ovipositor. The two eggs having 

 been placed on opposite sides of the opening, the beetle then took 

 her original position and continued making the chain of pricks 

 until the line was 5 inches in length. She then crawled back among 

 the branches of the tree. 



When the oviposition scar was examined closely the two openings 

 where the ovipositor had been thrust in were visible, both being 

 fhled with a brownish, semi transparent substance resembling wax. 

 Occasionally a series of punctures is found in which there occur two 

 of the oviposition furrows, each having one or two eggs. 



LENGTH OF LIFE OF BEETLES. 



Most of the beetles kept for observation were confined in roomy 

 wire-screen cages placed over young apple trees in the field. In 

 this position their length of life was probably something near normal. 

 About one-half of the beetles died within a month after emergence, 

 but a few lived for a considerably longer period. One male attained 

 an adult age of 52 days, while a female lived 93 days. The latter 

 individual died on August 30 and continued to oviposit up to within 

 a few days of its death. 



NATURAL ENEMIES. 



By far the most effective natural check to the increase of this 

 borer seems to be the woodpeckers. The borers feed in positions 

 easily accessible to these birds and empty burrows are to be found 

 on almost every infested tree, with the marks of the birds around 

 the wounds giving unmistakable evidence of the cause of the borer's 

 disappearance. (PI. V, B.) During the present studies every 

 attempt to rear larvse in unprotected trees met with a loss of all the 

 individuals as a result of woodpecker attack. The species of bud 



V 



