PROCEEDINGS, 1915. 31 



to be sure of this point, it would be necessary to secure the adults before, 

 or just after, they left their winter quarters. 



Of the total number of eggs laid, 25 hatched, nine of which were 

 reared to the pupal stage and data taken of their aphid consuming capac- 

 ity. 



Table No. 9 gives details of their life history and number of aphids 

 consumed. 



Adults were kept in the cages and fed in the same manner as the 

 larvae. In the period kept they ate on an average of 4 aphids a day, but 

 this does not probably represent the normal number, as they do not thrive 

 in confinement and ultimately die. At the approach of cold weather the 

 adults in the orchard seek some shelter in which to pass the winter. 



During the past season the Adalias were very numerous in most 

 orchards and in many cases prevented the aphids from doing any great 

 amount of damage. 



Control by Spraying. Certain investigators have reported excellent 

 results from dormant sprays applied to the egg. This is possibly due to 

 the fact that only a small proportion of the eggs hatch under ordinary 

 conditions. According to our results secured by counting 23,000 eggs of 

 aphis pomi, the number which hatch normally was 11.5 per cent. Others 

 have secured a much higher figure than this and still others as low as 3 

 per cent. In order to secure accurate results in our experiments, we de- 

 termined the number that hatched from an equal number of sprayed and 

 unsprayed eggs, in each case the difference between the two totals giv- 

 ing the approximate number killed. 



Lime Sulphur solution 1-10, Lime sulphur solution and lye, Sulphur 

 rf sin solution and Blackleaf 40, 1-500 were used in the dormant sprays. 

 Though a large proportion of eggs were killed by the treatment in no 

 case was the number sufficient to make any of these sprays a commercial 

 success. 



The control of the pest by dormant sprays was accordingly aband- 

 oned and various summer sprays were experimented with at several dif- 

 ferent dates. To sum up the results obtained, the most satisfactory 

 treatment for both species was Blackleaf 40 in the strength of 1 pint to 

 900 gallons of water, applied when the leaves about the blossom clusters 

 began to show green. This may be used in conjunction with lime sulphur 

 and arsenate of lead. Flour paste considerably improves this mixture as 

 an insecticide. When used alone 1 lb. of soap added to the mixture im- 

 proves Black leaf 40 as a spray, but of course, soap cannot be added to 

 a mixture containing lime sulphur. 



With the green aphis this spray may be deferred if necessary until 

 the spray just before the blossoms open, provided the trees are not too 



