382 



Severin (H. C.) & GiLBERTsoN (G. I.)- Grasshoppeis and their Con- 

 trol. — South Dakota Agric. Expt. Sta., Brookings. Bull. no. 172, 

 February 1917, 36 pp., 15 figs. [Received 28th June 1917.] 



The grasshoppers that do so much injury to lucerne crops in 

 S. Dakota are Melanoplus differentialis, Thorn, (differential locust), 

 M.fenmr-rubrum, De G. (red-legged locust) and M. bivittatus, Say. (two- 

 lined locust), which are all non-migratory forms, and to a less extent 

 M. atlantis, Riley (lesser migratory locust). Their natural enemies 

 are chiefly birds, especially plovers, hawks, blackbirds, crows, owls, 

 robins and several kinds of sparrows. Toads, lizards, ground squirrels 

 and mice also destroy large numbers of young and adult insects. At 

 times, certain parasitic flies exert a complete control. Under favour- 

 able conditions of high temperature and great humidity, two fungus 

 diseases attack and destroy large numbers. Grasshopper eggs are 

 destroyed by the larvae of the Meloidae (blister beetles), as well as 

 by both larval and adult ground-beetles. Control measures directed 

 against the eggs consist in deep winter ploughing followed by harrow- 

 ing and, if necessary, rolling to prevent the emergence of any young 

 that may hatch out. The adults may be destroyed by means of 

 poisoned bran bait consisting of coarse flaked bran 25 lb., white arsenic 

 or Paris green 1 lb., lemons or oranges 6, cheap molasses 2 quarts, 

 water 4 U.S. gals., or by the less effective but far cheaper Griddle 

 mixture, composed of : — fresh horse- droppings free from straw 50 lb., 

 white arsenic or Paris green 1 lb., lemons or oranges 6-8. Mechanical 

 methods, such as the use of the hopper- catching machine and of the 

 hopperdozer and the burning of weed patches in spring, have also 

 proved effective in reducing grasshopper outbreaks. 



Faurot (W. F.). Spraying Machinery. — Missmiri State Bd. Hortic, 

 Columbia, Qrtly. Bull. no. 65, vi, no. 1, January 1914, 99 pp., 

 14 plates. [Received 28th June 1917.] 



The author lays stress on the fact that time is the most important 

 element in spraying. Hence, an efficient spraying outfit should include 

 a supply tank and storage tank, and, unless the one can be loaded 

 from the other by gravity, it should be equipped with a tank-filler, 

 which also can be used for transferring the load to the spray tanl^. 

 Three kinds of tank-fillers are described and illustrated. 



Petherbridge (F. R ). Spraying for Apple Sucker {Psylla mali). — 



Ann. App. Biol.. London, ii, no. 4, April 1916, pp. 230-234. 



[Received 28th July 1917.] 



The experiments detailed in this paper, w^hich are a continuation of 



the work described in a previous publication [see this Review, Ser. A, 



iii, p. 278], indicate that lime and salt may be effective in preventing 



a large proportion of the eggs of Psylla mali from hatching. Lime 



wash was fairly effective. For spraying after the suckers had hatched, 



soft soap 10 lb., and nicotine (98 per cent.) 8 oz., to 100 gals, water, 



proved effective in killing the insects. Treacle 6 lb., nicotine 8 oz., to 



100 gals, water also formed a wash which penetrated well and was 



effective. Spraying to prevent the eggs from hatching was found 



insufficient to keep the insect under control and should be followed by 



the second spraying to kill those which have hatched. 



