260 EXPERIMENT STATION KECORD. IVol. 43 



sary to invert over the sealed cell a large watch glass and over this In turn a 

 tumbler. Six or 7 days are required for incubation of the egg. 



There appear to be 5 larval instars, about 60 days being required for the 

 larval development. When mature, the larva always seeks the extreme base 

 of the stem where it soon begins Its preparation for hibernation. It first cuts 

 a V-shaped groove entirely around and inside the stem, usually at or a little 

 above ground level. This groove never severs the root completely, but so 

 weakens it that the upper stalk, swayed by the wind, will break off completely 

 when dry, leaving a stub that is very characteristic of the work of this insect. 

 In this way the larva provides for the easy escape of the adult in the follow- 

 ing summer. The length of the stub thus formed varies greatly ; in Elyrnus 

 condensatus, It sometimes will project as much as 3 or 4 in. above the ground, 

 while in other grasses, and especially in wheat, stubs easily can be found less 

 than an inch in length in all. The longevity of the lar^je is quite remarkable, 

 at least one lai'va having lived 3 years and 5 months in stubs set in sand 

 indoor. The duration of the pupa period is not more than a week at the most. 

 By splitting stubs of grass or grain in June, the author has repeatedly liberated 

 adults, which, when free, were able to take instantly to wing. A life history 

 diagram is given ; also a key by S. A. Rohwer for the separation of C. cinctus 

 and C. pygmwus. 



Pleurotropis utahensis Cwfd., which kills the larva after it has formed Its 

 hibernation cell, is the most common parasite. It is gregarious, as many as 12 

 of its larvae having been taken from a single cell, but 5 or 6 is a more common 

 number. It is estimated that possibly 10 per cent of the Cephus larvae in native 

 grasses in Utah, are destroyed by this parasite, but in Bottineau County, 

 N. Dak., in some localities, it has killed more than 50 per cent of the larvae in 

 Bromus and timothy. But few parasites have been found in the stems of 

 wheat, apparently due to the fact that they have not adjusted their habits to 

 the modified feeding habit of Cephus. A braconid, Microbracon cephi Gahan, 

 also attacks the larvae in grass stems and kills them before maturity. 



Because of the multiplication of useful parasites, it is probably inadvisable to 

 mow infested grass in midsummer. Burning the stubble in the autumn or 

 spring appears to have little effect upon Cephus larvae, since the inhabited 

 stems have been cut at the ground level or below and are often covered with 

 soil. Plowing from 5 to 6 in. in depth is thought to be the best remedy for the 

 sawfly that can be suggested at present. 



A brief reference is also made to C. pygmceus, a well known European 

 species, the habits of which resemble those of C. cinctus but which does not 

 occur west of the Mississippi River. 



Trombidium akamushi and similar mites from Japan, Korea, and For- 

 mosa, K. MiYASHiMA and T. Okumura {Abs. in Rev. Appl. Ent., 7 {1M9), Ser. 

 B, No. 12, p. 182). — The authors consider Leptus autumnalis Shaw, occurring 

 in Formosa, to be the same form as described from England. Trombicula 

 mediocris Berlese, a similar form in Formosa, is closely related to Trombicula 

 sp. reported from Java, but is quite different from the adult of the red mite 

 T. akamushi. 



FOODS— HUMAN NUTRITION. 



Food industries, P. Petit (Les Industries de V Alimentation. Paris: Payot 

 & Co., 1919, pp. 238, figs. 2). — This book gives a brief review of some of the 

 more important food industries of France, with particular emphasis on the 

 Importations and exportations of the raw and finished material, the impor- 

 tance of the industries for the country, and means for furthering their de- 



