309 



A shallow pan, constructed large enough to cover the ground under 

 one-half of a plum tree, of the Mariana variety, was placed in position 

 on April 24, and kept continually filled with water until August 10. 

 Now, not only were females observed in the act of ovipositing in plums 

 hanging directly over the pan, but the latter contained from time to 

 time quite large numbers of punctured fruit ; nevertheless, the only 

 plums on the tree reaching maturity were among those hanging directly 

 over the water. 



Explanation. — a=Blackman Plum ; b=Wild Plum ; c=Wild Goose Plum ; d=Bogg8' 

 Plum; e=Crab Apple; f=Late Cherry; g=May Cherry; o=Seedling Apple; 

 h=Moore'8 Arctic Plum ; i = Qumce; j=Pear. 



A single experiment was made to determine the duration of life, and 

 the probability of the female ovipositing, after having partaken of 

 poison. Twelve females taken from the plum tree on May 17, where 

 they were evidently ovipositing, were kept for 24 hours without food, 

 some eggs having in the meantime been deposited in the box where 

 they were confined. At 5 p. m. they were removed and placed separ- 



