448 



McCoLLOCH (J. W). Additional Notes on the Use of Dust Sprays 

 against the Corn-Ear Worm. — Jl. Econ. Entom., Concord, ix, no. 4, 

 August 1916, pp. 395-398, 3 tables. 



The experiments recorded in this paper were undertaken to deter- 

 mine (1) the number of appUcations of lead arsenate to control the 

 corn-ear worm [Chloridea obsoleta, F.] ; (2) the value of lime, flour, 

 sulphur, etc., as carriers of lead arsenate ; (3) the relative values of 

 mixtures containing 75 per cent, and 50 per cent, of arsenate of lead. 

 In the first series of experiments it was found that injury by C. obsoleta 

 and by fungi decreased in proportion to an increase in the number of 

 applications of a mixture of 75 per cent, lead arsenate and 25 per cent, 

 sulphur. Plants dusted once showed about 5 per cent, insect injury 

 while fungi were prevalent ; those dusted eight times showed less 

 than 1 per cent, insect injury and fungi were absent. Controls were 

 attacked to the extent of 8 per cent, of the grain by C. obsolete, and at 

 the same time were badly infested with fungi. The above mixture 

 was found to be superior to that containing only 50 per cent, of lead 

 arsenate. Sulphur was a better carrier than either lime or flour and 

 showed some indications of value as a fungicide. 



DoANE (R. W.), A New Species of Isosoma attacking Wheat in Utah. 



— Jl. Econ. Entom., Concord, ix, no. 4, August 1916, pp. 398-401, 

 1 fig., 1 plate. 



Isosotna grande and I. vagmicolum, sp. n., cause serious injury to 

 wheat crops in the so-called dry farm regions in Salt Lake Valley. 

 7. vaginicolum was first observed in May 1914, when adults appeared 

 in a field of winter wheat. Eggs were deposited during the same 

 month in the base of the leaf-sheath, just above one of the joints near 

 the middle of the stem ; from 3 to 20 eggs were placed in this position. 

 The larvae occupied an oval cell in the sheath, and the latter became 

 swollen and hardened so that the flow of sap was prevented. In 

 consequence, the development of the flower-heads was partly or 

 completely arrested. The total loss in the crop was estimated at from 

 50 to 75 per cent. More than one generation occurred during the year. 

 The winter was passed in the larval stage in the stems, and pupation 

 of the over- wintering generation took place in April and May, I. grande 

 is not confined to the Salt Lake Valley, as is the preceding species, but 

 occurs also in well irrigated districts. I. tritici was present in small 

 numbers. The abundance of Isosoma in the Salt Lake Valley is greatly 

 increased by the fact that wheat is sown in every alternate year, and 

 during the intervening periods the land is allowed to lie fallow. Plough- 

 ing, if carried out at all during the fallow period, is performed with a 

 disk plough, so that a large quantity of stubble is left on the ground. 

 Frequently a self-sown crop is allowed to mature. The conditions 

 are thus eminently suited to the rapid increase of Isosoma spp, 



Pennington (W, E.). Notes on Rhogas terminalis, Cress. (Hymen- 

 optera, Braconidae).— JL Econ. Entom., Concord, ix, no. 4, 

 August 1916, pp. 401-406, 1 fig., 1 plate, 1 table. 



During an outbreak of Cirphis (HeliopMla) uniptmcta, Haw., in 1914, 

 observations were made on the parasites of this insect, especially on 



