X918 ENTOMOLOGIC AL SOCIETY. 67 



Natueal Control. 

 Insect Enemies. 



Like most species of plant lice the cherry aphis is harassed by many insect 

 enemies. Amongst these enemies are numbered .the following:— 



Coccinellida— AtZdZia hipunctata Linn. (Apparently the most important 

 predator), Coccinella d-notata Herbst., C. tmnsverso guttata Fabr., C. trifascuita, 

 Linn., C. sangumea Linn., Anatis 15-panctata Oliv., Hippodamm 13-punctaiu 



and Scymnus collaris. 



Syv-phidse—Syrphus americanus Wiedemann, S. rihesvi Lmn., AUogMpta 



oiliqua Say. 



Cecidomyiida3 — Aphidoletes meridionalis Felt. 

 Chry&opidad—Chrysopa sp. (No lace-wing flies were reared). 

 Acarina— An undetermined, bright, orange red species. 



Weather Agencies. 



Undoubtedly the most effective weapons employed by Nature in checking 

 the multiplication of this, and other species of plant lice are weather agencies. 

 Heavy rains wash off large numbers of aphids, especially in spring before the 

 pseudogalls are formed. Droughts are frequently disastrous to the lice, chiefly,, 

 we think, because such weather deprives the host plants of succulency. Early 

 frosts and wind storms also may destroy countless numbers of immature sexuall 

 females by causing the foliage to drop prematurely. 



Artificial Control. 



The cherry aphis is most vulnerable early in spring just before the buds 

 break. At this time all the eggs have hatched and the young stem mothers, 

 feeding on the buds, are absolutely without protection. Thorough spraying at 

 this stage with a good aphidicide will destroy all or practically all the lice. 



Last spring, we tested this remedial measure in a Vineland orchard. One- 

 half of the orchard — the check — was given the usual treatment with lime sulpliur. 

 In the other ^lialf, lime sulphur combined with Black Leaf 40 (% pint to SO 

 gallons) was used and the application was not made until shortly before the 

 buds burst. Because of the slow multiplication of the lice on the check trees, 

 due to unfavorable meteorological conditions, the results obtained from this experi- 

 ment did not show up to advantage until early July. At that time, tlie following 

 notes were made : — - 



"Examined all the trees sprayed with Black Leaf 40 and found onlv one 

 small colony. In the check block all the trees are more or less infested and 

 some are badly attacked. By noting the condition of the foliage — normal or 

 curled — it is a simple matter to tell where the treated rows end and the unsprayed 

 section begins." 



Literature Cited. 



(1) Slingerland and Crosby: 



Manual of Fruit Insects, p. 312. 



(2) Sanderson, E. D. : ' * ^ 



Insect Pests of Farm, Garden and Orchard, p. fiOG. 



