1064 EXPERIMENT STATION RECORD. 



The natural enemies of the field slug- observed in the greatest abun- 

 dance by the author are Talpa, Grvllotalpa, Procrustes cor Ulceus^ SUj'Jm 

 Imvigata, and Lanvpyris noctiluca. A great variety of remedies were 

 tried by th(> author for the purpose of destroying the iield shig. Among 

 the pulverized insecticides, mention should be made of carl)onate, oxid, 

 hydroxid, sulphate, and sulphid of calcium, ashes, dust, sulphur, 

 pyrcthrum. chrysanthenunn, and tobacco. White hydroxid of calcium 

 dusted upon the field slug caused a severe irritation of the skin which 

 I'esulted in the death of the majority of them. The brown hydroxid 

 of calcium and the oxid of calcium were less efficacious. Ashes proved 

 to be of little value, as nearl}" all the Limax dusted with this substance 

 ultimately escaped. Pyrethrum powder and dusted tobacco were of 

 little avail in combating the field slug. Nearh^ the same list of sub- 

 stances was tried b}- way of direct applications on plants for the pur- 

 pose of preventing the attack of the field slug. 



From the numerous insecticide experiments conducted by the author, 

 it is concluded that pulverized white hydroxid of calcium or the same 

 substance in a 1 to 2 per cent solution in water is the most active remedy 

 for the destruction of the field slug. As the second most effective 

 remedy, the author mentions white oxid of calcium. According to his 

 experiments, the most appropriate time for applying artificial remedies 

 in the destruction of Limax is fi"om S to 9 o'clock in tlu^ evening. 



Means of protecting barks and ■woods against insects, E. Mer 

 {Bui. 8oG. Nat. Agr. France, 60 {1900), No. 11, ]jp. 073, 074).— U was 

 observed b}' the author that two ^^ears after ringing a number of cork 

 oaks, the region immediatel}'' above the ring was badly infested with 

 bark beetles and had been much visited by woodpeckers for the pur- 

 pose of feeding upon these insects. The region immediately below the 

 ring, however, was entirel}^ free from bark beetles. Since it is known 

 that ringing, if performed so deeply as to injure the cambium, has 

 the effect of causing an accumulation of starchy materials innnediately 

 above the cut and the almost complete absence of such materials l)elow 

 the cut, it is suggested by the author to use any means which will hasten 

 the resorption of starch from the bark or which will serve to protect 

 this substance from future insect attacks. Specimens which are intended 

 for museum purposes may be cut in winter or early spring from branches 

 out of which the reserve materials have been removed for winter storage 

 to a lower position. 



Spraying, L. C. Corbett {West Virginia Sta. Bui. 70, pj). 353-382, 

 figs. 17). — A test of the value of spraying was made on an apple 

 orchard 30 3"ears old, with trees standing 33 ft. apart. The trees were 

 regularly sprayed through the season of 1899. In 1900 the orchard 

 was sprayed with Bordeaux mixture and Laurel green, the applications 

 being made on April 19, May 23, June !S, and June 23. The results 



