1911] Notes on the Pear-Sing 185 



The second egg parasite, Closterocerns cinctipennis Ashmead, 

 also determined by Girault, was reared equally abundant in 

 1909 and 1910, from eggs collected at Ames. This species 

 also affected both broods of eggs, emerging from first brood 

 eggs June 28 to July 22, and from second brood eggs August 4 

 to August 21. 



This parasite was always reared singly from the eggs. The 

 black form of the parasitic pupa could often be distinguished 

 within the parasitized eggs. It is presumably a primary 

 parasite. 



Predaceous Enemies. In 1910 nymphs and adults of 

 Podisiis maculiventris Say were found to be very active against 

 the slugs. Most frequently the slugs themselves were attacked, 

 but the Podisus also captured the adults, according to observa- 

 tions made by Mr. T. M. McCall. 



One Podisus nymph was kept 47 days in an insectary cage, 

 during which time it ate 66 slugs; 1.4 slugs a day. The great- 

 est activity was immediately after the insect became an adult, 

 when it ate 6 and 7 slugs a day. 



A species of Chrysopa and an undetermined Reduviid were 

 also observed to prey on the slugs. 



experiments with insecticides. 



Paris green, 1 pound to 150 gallons of water, was effective. 

 A home-made arsenate of lead, single strength, was not effect- 

 ive. Used against the older slugs this spray was very ineffi- 

 cient. I could not see that any slugs at all were killed by it. 

 When used against the very young slugs, about half of them 

 were killed. 



A 10% solution of kerosene emulsion appeared to be quite 

 effective. 



Several simple soap solutions were found effective, at con- 

 centrated strengths. Whale oil soap, 1 pound in 2 gallons of 

 water; Ivory soap, 1 bar in 2 gallons and White Laundry soap, 

 1 bar in 2 gallons of water, were all satisfactory treatments. 

 These soap solutions may be quite convenient for use on a few 

 cherry trees when the fruit is present. 



