852 EXPERIMENT STATION RECOBD. [Vol.41 



"Another interesting fact with regard to the extrinsic life of this organism is 

 that it can multiply steadily at a temperature from 18 to 37° C. [64.4 to 98.6 F.l 

 The optimum temperatui'e at which it remains viable for many months is 26°. 

 The climate in most of tlie tropical countries offers optimum conditions both 

 for L. ictcroidcs and for the mosquito, which carries and nourishes it." 



Notes on Allcgrapta fracta (Diptera: Syrphidae), W. IM. Davidson {Canad. 

 Ent., 51 (1919), No. W, pp. 235-239, fiij. i).— These notes relate to the habits of 

 a predaceous syrphus fly observed in tlie Imperial Valley in California in the 

 spring and early summer of 1918. 



The larvfe were specially beneficial to barley from March 1.5 to April 30, 

 at which date most of the grain had ripened, and to corn during May and 

 June. In fields in which they were specially abundant 25 per cent of the in- 

 fested heads had larvfe working on the aphids. Experiments showed that 

 a larva could, during its lifetime, eat all the aphids on from three to four heads 

 of grain of average infestation. In one field of 20 acres, examined on a num- 

 ber of occasions, it appeared that A. fracta was responsible for an almost total 

 destruction of baidey aphids. 



Larvfe of Eupodes volucris, SyrphUH americnnun, A. obliqua, and Catahomha 

 f)irrast7'i were present in the barley and corn fields, but in mucli smaller num- 

 bers than those of A. fracta. 



In the Los Angeles district of southern California, ^l obliqua is very abun- 

 dant and A. fracta comparatively scarce, whereas in the Imperial Valley the 

 reverse holds true. In 1918 A. fracta was not reared from any other host than 

 Aphis maidis, except that a single larva was taken attacking A. pseiidobrassico'. 



A contribution to the knowledge of Brazilian CEstridae, A. Ltjtz (Mem. 

 Inst. Oswaldo Cruz, 10 (191S), No. 2, Trans., pp. 118-137). — A translation of the 

 paper previously noted (E. S. R., 40, p. 458). 



The prevention of blow-fly attacks on sheep by spraying, A. H. E. Mc- 

 Donald (Afjr. Gas. N. S. Wales, 30 {1919), No. 6, pp. 403-JtOo, firjs. 3).— This is 

 a brief statement of tests of dips, consisting of sheep-dip powder, a carboli<? 

 liquid dip, and a mixture containing arsenate of soda. While treated sheep 

 were not absolutely protected from attacks by the sprays, the percentage of 

 affected sheep was only 33 per cent against 54 per cent in the untreated group. 



Experiments for the control of the grape root- worm, F. Z. Hartzell {Neio 

 Yorl; State Sta. Bnl. A53 (1918), pp. 257-332, pis. 10, figs. 8).— This buUetiu 

 gives a brief account of the life history, habits, and economic importance of 

 Eidia viticida (pp. 261-269) followed by a detailed account of control experi- 

 ments conducted over a period of six seasons, much of wliich data is presented 

 in tabular form. 



The experiments have led the author to recommend two methods of control : 

 (1) The application of molasses 2 gal., arsenate of lead 6 lbs., and water 100 

 gal., followed in about one week with an application of Bordeaux mixture 

 (8:8:100) and arsenate of lead 6 lbs.; (2) two applications of Bordeaux 

 mixture (8:8: 100) and arsenate of lead 6 lbs., at an interval of about 10 days. 

 The first system of treatment is specially recommended when the beetles are 

 present in excessive numbers, while the second is advised for general vine- 

 yard spraying when beetles are not abundant. "The addition of molasses 

 destroys the adhesiveness of the arsenate of lead [E. S. R., 38, p. 858], thus 

 necessitating the precaution of applying the material at a time when the 

 weather conditions indicate that no rain is to be expected for several days. 

 A supplementary treatment should be made in about one week with Bor- 

 deaux mixture and poison to protect vines from invading beetles. Two gal. 

 of molasses in each 100 gal. of spray produced better results than 1 gal." 



Two sprayings with Bordeaux mixture and arsenate of lead, thoroughly 



