313 



Possibly the insects had been introduced into the greenhouses in the 

 soil. The larvae feed on the roots, but the greater part of the damage 

 is done by the adult beetles, which eat the young shoots and leaves 

 of the rose trees, growing quickly under the forcing conditions of the 

 greenhouse. They feed at night, feigning death if disturbed. The 

 infested greenhouses were visited in July, but l^efore this serious 

 damage had been experienced from the beginning of May, and 

 various attempts had been made to control it. A mixture of lead 

 arsenate and Paris green in water did not adhere well, and was 

 ineffective. One part of kerosene emulsion to sixteen of water killed 

 the beetles, but caused serious scorching of the plants. Nicofume 

 liquid (36 teaspoonfuls to 4 U.S. gals, of water) stuj^efies. but does not 

 kill the insects. 



In the tests here described, the plants were thoroughly sprayed 

 with lead arsenate at the rate of two to two and half pounds to fifty 

 U.S. gals, water and twenty-five ounces of soap. This did not injure 

 the plants, but. contrary to experience with strawberries, was not 

 effective. This was due to the insects choosing the fresh, tender 

 growth that was being forced during the hot sultry nights and avoiding 

 the sprayed foliage. Fumigation with hydrocyanic-acid gas was then 

 tried. Half an ounce to a thousand cubic feet of space produced no 

 result, and the maximum dose that roses can withstand, using two 

 ounces to a thousand cubic feet of space, was therefore tried. As a 

 result 97 per cent, of the beetles were killed. Almost all the tender 

 growth was more or less scorched, but recovered in three weeks, 

 while this deprived the few remaining beetles of their favourite 

 place of feeding. In this way a large percentage of females are killed 

 many months before normal egg-laying time. 



In the discussion that followed this paper Mr. A. Peterson described 

 the results of three years' study of this insect in a rose-house in New 

 Jersey. In that State there are two generations a year, the adults 

 appearing in June and July and again in September. The winter 

 is passed in the adult stage in the soil. No satisfactory control had 

 been found. Hydrocyanic acid gas (1| oz.) applied in August, 

 scorched the foliage so seriously that it did not recover that season 

 without killing more than a small percentage of the beetles. Dusting 

 with a lead, sulphur and lime mixture in June and July gave promise 

 of control, but the only method in use consists in beating the bushes 

 and catching the beetles as they fall. 



Flint (W. P.). Poison Baits for Grasshoppers. — .//. Econ. Enfom., 

 Concord, N.H., xiii, no. 2. A])ril !9-_>0. pp. 232-237. 



The preference that giasshoppers show for leguminous ])lants, 75 

 per cent, of the damage done by them in Illinois being to clover, lucerne, 

 soy beans, cowpeas, and similar plants, suggested that a bait with a 

 strong leguminous odour might possibly prove more attractive than 

 the standard bran-molasses-lemons bait [E.A.E., A, vii, 206, etc.|. 

 Lucerne meal has been tried, but has not the necessary fresh odour. 

 During 1918 and 1919 a series of experiments were made using the 

 standard bait, and, for comparison, a bait nuide of twenty-five p(mnds 

 of bran and one pound of Paris green mixed dry, and a stiff mash made 

 by adding water in which had been stirred three pounds of finely 



