132 ENTOMOLOGICAL NEWS. [April, 'o6 



about) were killed, but the weevils were not injured in the 

 least. 



In 1897 (Rept. Ottawa Expt. Farms for 1897, P- 106). 

 Duchess apple trees were sprayed in Canada with formalin at 

 the strengths of 1, 2, and 4 ounces to 5 gallons water. No 

 injury or benefit resulted to the foliage or fruit, except a slight 

 indication of some deterrent influence against the codling- 

 moth ; plant-lice were not killed. 



In 1900, C. P. Lounsbury, Government Entomologist of 

 Cape of Good Hope, South Africa, reported (his Report for 

 1899, p. 17) the following important experiment in fumi- 

 gating railway carriages for bedbugs. The experiment was 

 made under supervision of a professional chemist. ' ' The 

 bedbugs were not destroyed even when left exposed for two 

 full days in a carriage, treated with all the gas contained in 

 800 c.c. (about 12 ounces of formaldehyde, or not quite as 

 strong as I used it) of the water solution of formalin. The 

 gas was forced into the carriage under heavy pressure, and 

 the bedbugs were enclosed in a piece of mosquito netting sus- 

 pended near the middle of the space. The carriage was of 

 about 2,500 cubic feet capacity, and all its cracks, crevices 

 and air-holes were tightly stopped with cotton wool. House- 

 flies and aphids shut in the carriage were found dead, but 

 larvae and adult scale insects of several species, and plant- 

 bugs of three species were found to have survived. Formal- 

 dehyde gas of far greater but indefinite strength, generated 

 from formalin tablets, was also inefficacious in destroying im- 

 prisoned bedbugs." 



Finally, there has just come to hand the report of another 

 experiment by Prof. Dr. K. L,ampert with formaldehyde 

 against insects in Germany (Zeitschrift fur Wissenschaftliche 

 Insektenbiologie, Vol. XI, January 31, 1906, p. 12). In a 

 room containing about 70 cubic meters (2,400 cu. ft.) 1,100 

 c.c. of 40 per cent, formalin (= about 17 ounces of formalde- 

 hyde, or stronger than I used it in my experiment) was gen- 

 erated for 4 hours. A number of cockroaches (B. orientalis 

 and- germ a nica), 2 spiders, several larvae of the larder beetle 

 (D. lardarius) , some sow-bugs, 3 larvae of saw-flies, meal- 



