342 



beetles, presumably acting as a repellent. Gypsum and ground lime- 

 stone were less effective owing to being less adherent than finer and 

 lighter powders. Air-slaked lime was effective, but caused some scorch- 

 ing of the leaves. Fish-oil and sawdust mixed together and sprinkled 

 on the ground around the plants seemed to repel the beetles until the 

 plants Avere out of danger. All dry powders are best applied when the 

 foliage is wet. 



Brittox (W. E.) & Zappe (M. P.). Tests of Sprays to control the 

 Potato Aphid.— i(S//i Rept. Connecticut State Entomologist for 1918, 

 Conn. Agric. Expt. Sta., New Haven, Bull. no. 211, 1919, pp. 294- 

 297. [Received 5th June 1919.] 



The difficulty of using soap in a nicotine solution in combination 

 with arsenical poisons, on account of its liability to unite with the 

 arsenate and injure the plant tissues, has led the authors to make 

 tests with several spraying materials, using potato plants infested 

 with Aphids for the experiments. Blackleaf 40, with sufficient soap 

 to cause suds to appear when the mixture is shaken, killed a large 

 percentage of Aphids when sprayed upon them. Common salt and 

 water, commercial lime-sulphur, both with water and combined 

 with nicotine solution, nicotine solution and molasses, were all tried 

 with very little success, though none of them injured the plants. 

 Casein, 1'5 grams, with quicklime, 3'5 grams, mixed and added at the 

 rate of 4 oz. to 50 U.S. gals, of Blackleaf 40 and lead arsenate spray, was 

 of questionable value as a spreader and did not apparently render 

 the nicotine solution any more effective in killing Aphids. Nicotine 

 oleate alone, with soap bark [Saponaria bark] and with glycerine killed 

 many Aphids, but did not seem any more effective than Blackleaf 40 and 

 soap. The best formula for kerosene emulsion proved to be 3 U.S. gals, 

 kerosene, 4 cakes soap (about 40 oz.) in enough water to make 50 U.S. 

 gals, spray. This mixture was very effective in killing Aphids. 

 Nicotine solution and soap at current prices were more than twice as 

 expensive besides being difficult to obtain, but required less 

 labour to prepare. 



Zappe (M. P.). Life History and Development of the Greenhouse 

 Cockroach, Pycnoscelus siirinamensis, L. — 18th Rept. Connecticut 

 State Entomologist for 1918, Conn. Agric. Expt. Sta.. New Haven, 

 Bull. no. 211, 1919, pp. 311-313. [Received 5th June 1919.] 



These further studies on Pycnoscelus sumiamensis, L. (greenhouse 

 cockroach) [see this Review. Ser. A, vi, p. 460] deal with the immature 

 •stages and life- history. This insect evidently requires a hot, moist 

 atmosphere for development, and shows a decided preference for 

 greenhouses where the temperature is between 70° and 80° F. 

 during the day and never lower than 60° at night. In the laboratory, 

 at a temperature of 36° to 40° F., 95 per cent, died within a week and 

 a temperature of 1° F. for 10 minutes proved fatal to them all. Indivi- 

 duals kept in test-tubes in dry sand or in dry boxes also died in a few 

 days, though the presence of a small quantity of moisture was sufficient 

 to keep them alive. No natural enemies have been observed in 

 Connecticut with the exception of a mite. P. siirinamensis undergoes 

 ,six moults from the egg to the winged stage, the average length of 



