472 



of A])Jiis pomi were killed at a strength of 1 to 800 and over, but 

 even the weakest solution used, 1 to 1,500, was effective, the fact that 

 a few individuals escaped being probably due to lack of thoroughness 

 in application ; to avoid this, soap at the rate of 3 lb. to 100 gals, of 

 solution was added to ensure more even distribution. This addition 

 proved to be of considerable benefit in aiding the liquid to penetrate 

 the curled leaves. The same solutions were used against the mealy 

 plum aphis, Hyalopterus arundinis, F., but the results were less 

 satisfactory, though its numbers were sufficiently reduced to prevent 

 injury to plum and prune trees before the migration of the Aphids 

 to other food-plants. Sprays of lime-sulphur (1 to 40 or 45) proved 

 effective in checking Paratrioza cockerelli, Sulc, on tomatoes. 

 Although the growth of the plant was temporarily checked, no vital 

 injury was caused by this appHcation and the insects were reduced to 

 a neghgible number. Nicotine sulphate, even at a strength of 1 to 

 200, proved useless against this Psyllid. 



Campbell (E. E.). U. S. Bur. Entom. A Suggestion of a possible 

 Control of Pea and Bean Weevils. — JL Econ. Entom., Concord, 

 N.H., xii, no. 4, August 1919, pp. 284-288. 



Observations show that late planting is an efficient measure against 

 infestation by the horse-bean Bruchid, Bruchus rufimanus, in 

 California. Provided there is plenty of moisture in the soil and water 

 for irrigation and the spring weather is not too hot and dry, this 

 method of planting after the oviposition period is over will prove 

 successful. It is suggested that owing to the similarity of the life- 

 history this measure might also be applicable against the pea weevil, 

 Bruchus pisorum, and possibly other allied Bruchids. 



The eggs of Bruchus rufimanus are laid from the middle of March 

 to the middle of May on the surface of green pods. They hatch 

 in 9 to 18 days and the larvae at once bore into the pod where they feed 

 for about 10 to 15 weeks. Pupation occurs in the eaten out cell of 

 the bean and lasts from 7 to 16 days. The adults live from 1 to 8 

 months. They may leave the bean at once or remain in it for several 

 months. They may be seen as early as August, but in storage 90 per 

 cent, are dead by the first of April. 



Smith (H. S.). On some Phases of Insect Control by the Biological 

 Method.— J/. Econ. Entom., Concord, N.H., xii, no. 4, August 

 1919, pp. 288-292. 



The biological control of insect pests, involving the increase by 

 artificial manipulation of already existing entomophagous insects 

 in infested regions is discussed. The chief points to be considered in 

 work undertaken on these fines are : the comparative reproductive 

 capacity of the host and the available entomophagous insects ; the 

 powers of locomotion both of the pests and their natural enemies ; 

 the sequence of available entomophagous insects ; the possibifity of 

 rearing or obtaining these insects in sufficient quantities ; the cost of 

 producing natural enemies in comparison with the value of the crop 

 and any known artificial control ; the presence of secondary parasites 



