30 



Herrick (G. W.). Field Experiments for the Control of the Apple 

 Maggot. — ■//. Econ. Ii)i/iiiii., Coiiconi, N.IL, xiii, no. 5, October 

 1920, pp. 384-388. 



The ap])lo maggot [Rhagoletis pomonella] is very destructive in the 

 Hudson Ki\'er N'alley and in Cohmibia county, New York, wlierc it is 

 one of the major apple pests. Spraying wi t h 3 lb. jxnvdered lead arsenate 

 to 100 U.S. gals, water about tlu' 3()tli June and again about the 17th 

 July has proved a successful remedial measure. The results of experi- 

 ments show that all apple trees liable to infestation should be sprayed 

 to prevent any migration of the flies from untreated varieties. All 

 derelict trees should be thoroughl}^ sprayed, or cut down and burned. 



Wellhouse (W. H). Wild Hawthorns as Hosts of Apple, Pear and 



Quince Pests. — Jl. Econ. Entom., Concunl, N.H., xiii, no. 5, 

 October 1920, pp. 388-391. 



The necessity for treating or destroying wild hawthorns {Crataegus) 

 in the vicinity of orchards is emphasised. Owing to the almost identical 

 habitat and botanical relationship between hawthorn and the 

 cultivated apple, pear and quince, many insects infesting it migrate 

 to the cultivated hosts. 



The most important species in this respect include Anihgnomns 

 nebulosus, Lee. (hawthorn blossom weevil), the habits and life-history 

 of which are identical with those of the apple blossom weevil of Europe 

 [A. pomontm] ; the Cosmopterygid, Blastodacna airvilineclla, Chamb. 

 (hawthorn fruit-miner) ; the leaf bug, Lygus univittatus, Knight ; 

 MacrosipJnim crataegi, Mon. ; Argyresthia oreasella, Clem. ; and the 

 leafhoppers, Empoa qiterci, Lamenia vulgaris, Erythroneura ohliqua 

 and Idiocerus provanchcri. 



The popular belief that the round-headed apple-tree borer, Saperda 

 Candida, and the codling moth, Cydia pomonella, are common feeders on 

 Crataegus has not been confirmed. 



Peterson (A). Some Studies on the Effect of Arsenical and other 

 Insecticides on the Larvae of the Oriental Peach Moth. //. Econ. 

 Entom., Concord, N.H., xiii, no. 5, October 1920, pp. 391-398. 



A series of experiments has been conducted under laboratory 

 conditions to ascertain the effect of arsenicals on the larvae of Cydia 

 {Laspeyresia) molesta, Busck. The technique employed is described, and 

 the results show that dusts are superior to sprays for combating this 

 moth, though in no case was there a complete control. Siuall larvae 

 were killed by applying to the fruit a dust consisting of 1 part lead 

 arsenate, and 5 parts hydrated lime or 1 part of finely ground sulphur. 

 The latter mixture is the more effective of the two. Calcium and 

 magnesium arsenates alone or in combinaticm with hydrated lime 

 killed almost the same percentage of larvae as the lead arsenate. Dust 

 of hellebore, tobacco and pyrethrum did not keep the larvae out of even 

 thoroughly coated fruit, although pyrethrum ai)parently has a shghtly 

 repellent effect. It was thought that spraying the twigs might poison 

 the larvae as they eat their way out, but the results of these tests were 

 not promising. Owing to lack of material the effect of sprays on newly- 

 hatched larvae could not be ascertained, but they are probably more 

 susceptible than the larger ones ; in this case it may be possible to kill 

 them all as they enter the fruit or twigs by thoroughly dusting them. 



