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O'Kane (W. C.) & Weigel (C. A.). Experiments with Contact Sprays 

 for Leaf Miners. — New Hampshire Agric. Expt. Sta., Durham, 

 Tech. Bull. 17, February 1921, 24 pp., 1 plate. [Received 

 6th December 1921.] 



The experiments described in this bulletin were undertaken in 

 1917, chiefly in connection with Tischeria malifoUella (apple-leaf 

 trumpet miner). Winter is passed as a full-grown larva, which 

 pupates with the approach of warm, spring weather, the adult moths 

 appearing shortly afterwards. Eggs were found in Connecticut in 

 early June, and probably appear in New Hampshire about two weeks 

 later. They hatch in about six days, and the young caterpillar 

 immediately begins to construct a narrow mine in the leaf ; this is 

 enlarged as the larva grows, until it has the characteristic trumpet- 

 shape. Most of the larvae of the first generation were full-grown 

 about 28th July ; many had pupated at that time. After 8-11 days 

 the adults began to appear, the maximum emergence being between 

 8th and 12th August. Oviposition begins about four days after 

 emergence. Eggs laid by these moths hatch in 4-12 da5^s. Growth is 

 apparently slower for the second generation larvae than for the 

 first — full size being reached in October, when a silken cell is spun 

 within the leaf, in which the winter is passed. 



The normal position of the larva in the mine is discussed ; it was 

 thought that this might be an important factor influencing the effect 

 of insecticides, but, as a matter of fact, no causal relationship was 

 discovered between position and mortahty. The spraying materials 

 used in the test were various strengths of nico-fume or Black-leaf 40, 

 with and without soap, lime-sulphur and kerosene emulsion. The 

 results of all the tests are shown in a series of tables. None of the 

 sprays used was very successful against mature larvae of T. mali- 

 foUella in the first generation ; young larvae of the second generation 

 were destroyed by sprays of nico-fume or Black-leaf 40, 1 : 100 or 1 : 200, 

 the mortality ranging from 73 to 37 per cent. ; kerosene emulsion 1 : 8 

 was rather less effective. Sprays apphed for the first generation gave 

 definite residual effects on the eggs of the second generation, laid two 

 or three weeks later, the mortality on foliage sprayed with nicotine 

 diluted 1 : 100 or 1 : 200 ranging from 93 to 70 per cent., as compared 

 with a normal mortahty of 22 per cent. Lime-sulphur and kerosene 

 emulsion gave no apparent residual effects. 



Miles (H. W.). Observations on the Insects of Grasses and their 

 Relation to Cultivated Crops. — Ann. App. Biol., Cambridge, 

 viii, no. 3-4, November 1921, pp. 170-181. 



Observations have been carried out in Shropshire over a period of 

 nine months on certain insects that infest grasses, cereals and other 

 crops, and are able, when these are not available, to subsist on other 

 grasses and plants in the vicinity. The methods of investigation and 

 the conditions of the soil, locality, rainfall, etc., are described, and 

 hsts are given of the insects found during the winter and those observed 

 during the summer, with the food-plants on which each was taken. 



The chief wireworms are Agriotes ohscurus and Athens haemo- 

 rrhoidalis, found in the greatest numbers on sandy soils with abundance 

 of root fibre in them. Land recently broken up was badly infested. 

 The larvae of A. haemorrhoidalis apparently prefer pastures and 

 meadows to arable land. The average depth of wireworms in 



