438 



The hot dry weather ckiring July and August materially reduced 

 the second brood of various species, especially Cirphis unipiincta. 

 Agrotis c-nignim and A. ypsilon are double-brooded in Minnesota, 

 Balsa malana was unusually abundant ; the larvae live on apple but 

 are apparently of no economic importance. There is no record of 

 the first brood of Cydia {Carpocapsa) ponwnella. 



Moore (W.). The Principles of Film-forming Sprays. — 18th Rept. 

 Minnesota State Eni., Agric. Expt. Sta., Univ. Earm, St. Paul, 

 18th June 1921, pp. 57-62. 



The forces that cause the spray to collect into drops or spread into 

 a thin film on the leaf surface are explained, and the method of making 

 the more desirable film-forming sprays is discussed. No particular 

 substance is definitely advocated as the cost and other factors must 

 be further considered. 



Oestlund (0. W.). Contribution to the Knowledge of the Group 

 Aphidina, Family Aphididae (Homoptera). — ISt/i Rept. Minnesota 

 State Ent., Agric. Expt. Sta., Univ. Farm, St. Paul, 18th June 

 1921, pp. 63-75. 



This paper supplements previous work [R.A.E., A, vii, 326] and 

 deals with the group Aphidina but without consideration of the 

 genera and species. Keys to the subtribes of the Aphidini and 

 and Macrosiphixi are given. 



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



Deraeocoris (Heteroptera, Miridae). — IStJi Rept. Minnesota State 



Ent., Agric. Expt. Sta., Univ. Farm, St. Paul, 18th June 1921, 

 pp. 76-210, 1 plate, 44 figs. 



The genus Deraeocoris now includes all the species that have been 

 described under Camptobrochis. Of the 54 species dealt with in this paper 

 37 are new, and of the 22 varieties 20 are new. The general scarcity 

 of these insects, compared with leaf-feeding species, is an indication of 

 their predatory habits. Several species live on conifers, where they 

 appear to be associated with Aphids and other soft-bodied insects. 

 D. pinicola, sp. n., feeds on Chermes pinicorticis, Fitch (pine-bark 

 Aphid), and D. nubilus, sp. n., probably has similar habits. D. larici- 

 cola, sp. n., apparently breeds only on larch (Larix laricina), and was 

 found feeding on the sap of the plant. D. aphidipliagus, sp. n., feeds 

 on Eriosoma {Schizoneura) americanum, Riley ; D. nitenatus, n. n. 

 (= nitens, Reut.) on E. (5.) lanigerum, Hausm., on elm ; and D.fasciolus, 

 sp. n., on Aphis sorhi, Kalt., on apple, E. (S.) cratacgi, Oestlund, on 

 Crataegus, and Phyllaphis fagi, L., on beech. 



Agee (H. p.). Director's Report. — Proc. 40th Ann. Meeting Hawaiian 

 Sugar Planters' Assoc, Honolulu, November 29th and 30th 1920 ; 

 1921, pp. 148-184. 



The achie\'ements of twenty-fi\e \'ears' work of the Station are 

 briefly reviewed. The parasitic control of the leaf-hopper, the 

 cane-borer and Anomala [oriental is^', and the service rendered on 

 manufacturing lines, are particularly mentioned. 



