112 



and grown rapidly on dandelion. Flax, beets, onions, cabbages and 

 carrots have also been recorded as food-plants. 



In trials with light-traps, from 12th August to 2nd September 

 {i.e., the whole flight season), 82,488 moths were caught, as many as 

 4,000 being captured in one night ; this method, however, is not 

 practicable for prairie conditions. 



The losses due to P. orthogonia during the last ten years are discussed 

 [R.A.E,A,ix, 584, 585, etc.]. 



Following upon the work of former years to determine the efficacy 

 of poison bran mash [R.A.E., A, iii, 620; iv, 346] experiments were 

 carried out in 1919 and 1920. The details of these are given ; the 

 results proved a failure in every case, in that, although the number 

 of cutworms was reduced, destruction of the crop was not prevented. 



A survey was undertaken in 1920 to determine the relation of 

 cultural methods to the abundance of cutworms. A high percentage 

 of injury was shown in all cases where the stubble was only disked or 

 harrowed before seeding. Fields that were ploughed either in autumn 

 or spring showed a somewhat lower percentage, while summer-fallowed 

 fields showed only the small loss of 8-5 per cent. The moths have a 

 decided preference for mellow fields in which to oviposit, and it is 

 evident that the physical condition of the soil during the oviposition 

 period has an important bearing upon the amount of injury in the 

 following spring. It seems as though the greatest injury may be 

 expected in fields in which the surface soil is loose and well-pulverised 

 during the egg-laying period. Such a condition may be due, in 

 summer-fallowed fields, to tillage in late July and August, or it may be 

 a natural condition. When a crop is removed during July or August, 

 the surface crust may become pulverised in many places. Since least 

 injury may be expected in fields where the surface soil is hard or 

 crusted during the oviposition period, it is advisable not to disturb 

 the ground between 15th July and 15th September. 



P. orthogonia is not greatly affected by insect enemies. Of 960 

 larvae collected in 1920, 13-7 per cent, were parasitised, 12-2 per 

 cent, by Diptera, and 1-5 per cent, by Hymenoptera. The parasites 

 included the .Tachinids, Bonnetia compta, Fall., and Peleteria robusta, 

 Wied. Wild birds are the most useful check, particularly the western 

 grasshopper sparrow {Antmodramus savannarum himaculatus) and the 

 horned lark {Otocoris alpestris leucolaema). The Carabid beetle, 

 Calosoma fepidum, Lee, is probably a less important predator. 

 A description of the stages of P. orthogonia is appended. 



Wade (J. S.) & Boving (A. G.). U.S. Bur. Ent. Biology of 

 Embaphion muricatum. — Jl. Agric. Res., Washington, D.C., xxii, 

 no. 6, 5th November 1921, pp. 323-334, 2 plates, 3 figs. 



The larvae of Embaphion muricatum, Say, and related species of 

 false wireworms have been for the past few years the cause of much 

 injury to growing wheat and other field crops in the semi-arid regions 

 of the middle western United States [R. A.E., A, ix, 162]. The steady 

 progress of cultivation of the grassy prairies has been an important 

 factor, the removal of native food-plants causing this and other beetles 

 to feed more and more upon cultivated grains. As the insect is a very 

 hardy one and rapidly adapts itself to changed conditions and to new 

 food-plants, it is a serious menace to grain production. Early records 

 of its occurrence and its distribution are described, as well as the 



