424 



80 per cent. Badly attacked seed did not mature in the pod but 

 shrivelled and became distorted. The adults seem to depend upon 

 the pod splitting to effect their escape. The danger of introduction of 

 the pest into the United States would therefore seem to he in permit- 

 ting shipment of green beans from Mexico. The author considers that 

 in the Mexico City district this is a worse pest than E. corrupta. 



CusHMAN (R. A.). U.S. Bur. Ent. The Identity o£ Hahrohracon 

 brevicornis (Wesmael) (Hym., Braconidae) .—Proc. Ent. Soc. 

 Washington, D.C., xxiv, no. 5, May 1922, pp. 122-123. 



Basing the determination of the species on the number of joints of 

 the antennae, the author, foUowing Marshall's determination, formerly 

 treated Bracon juglandis, Ashm., Hahrohracon hehetor, Johns (nee Say), 

 and B. [H.) honestor, Riley & How. (misprint for hehetor) as synonyms 

 of H. brevicornis, Wesm. The species for which this name has been 

 used is apparently invariably parasitic on Lepidopterous larvae, 

 such as Ephestia, Plodia and GaUeria, infesting stored products. 



In connection, however, with the importation into the United States 

 from Europe of parasites of Pyrausta mibilalis, Hb. (European corn- 

 borer), a species of Hahrohracon has been reared that is very closely 

 alhed to the one previously determined as brevicornis, and there seems 

 no doubt but that this European insect is the true H. brevicornis, 

 Wesm. It will therefore be necessary to call the parasite of storage 

 insects by the oldest name, which is juglandis, Ashm. The records 

 of H. brevicornis as a parasite of Dioryctria abietella and of Myelois 

 ceratoniae probably do refer to the true brevicornis. The characters 

 separating H. brevicornis, Wesm., and H. juglandis, Ashm., are given. 



Knight (H. H.). Monograph o£ the North American Species of 



i)^ra<3ocons— Heteroptera, Miridae.— t/«w. Minnesota Agric. 

 Expt Sta., Univ. Farm, St. Paul, Tech. Bull. 1, June 1921, 

 pp. 76-210, 3 plates, 44 figs. [Received 20th June 1922.] 



This monograph has previously been noticed from another source 

 [R.A.E., A, ix, 438]. 



Moore (W.). Spreading and Adherence of Arsenical Sprays.— 



Minnesota Agric. Expt. Sta., Univ. Farm, St. Paul, Tech. Bull. 2, 

 June 1921, 50 pp., 1 fig. 



The following is the author's summary of this paper: — 

 The addition of material similar in chemical constitution to the leaf 

 surface causes the spray mixture to form a film of liquid over the 

 leaf. The positive absorption of the added material at the leaf-spray 

 interface, resulting in a lowering of the interfacial tension, appears 

 to offer the best explanation of the results. Different types of leaves 

 naturally require different materials. Thus organic compounds such 

 as beechwood creosote, carvacrol, or amyl alcohol, soluble in fats 

 and waxes and but slightly soluble in water, produce good spreading 

 over waxy leaves, such as cabbage. Various proteins and plant 

 infusions give good spreading on leaves with surface of cellulose, even 

 when they are stronglv cutinised, as in the case of plum and citrus 

 leaves. Suspensions containing • small-sized particles adhere better 

 than those with larger particles. An even distribution of the spray 

 over the leaf tends to increase the adherence. The leaf surface, when 

 wet, exhibits a negative electric charge. The common compounds 



