48 



KEROSENE EMULSION AS A REMEDY FOR WHITE GRUBS.* 



Ou Juue 1, last, Mr. Cogan, superintendent of lawns at the Capitol 

 grounds, brought to the Division specimens of the larvae of Allorhina 

 nifitla and stated that they were doing serious injury to the lawns under 

 his care. This afforded an excellent opportunity for experimenting 

 with kerosene emulsion, and Mr. W. B. Alwood was instructed to visit 

 the grounds at once and to conduct a careful series of experiments and 

 observations. The results have proved most satisfactory and there 

 seems little question but that we have found a certain and easy remedy 

 for these destructive creatures. The ordinary White Grubs (larvae of 

 Lachnmterna spp.) will unquestionably be affected in the same way. 

 We give Mr. Alwood's report in his own words : 



REPORT BY W. B. ALWOOD. 



The plat affected was of irregular outline ; on a large portion of it the 

 grass was already killed and a considerable portion of this was bare of 

 herbage of any kind. The soil was everywhere full of worms, averag- 

 ing about six to the square foot of earth. 



A small plat was treated with kerosene emulsion diluted fifteen times. 



June 7, visited the grounds again. Where the keresene emulsion 

 had been used the grubs had been immediately sickened and were now 

 lying 2 to 4 inches below the surfiice, not eating. Mr. Cogan said that 

 the next day after the treatment he had dug up several grubs which 

 were sick and soon died when exposed to the air and sunshine. I found 

 no dead ones in the soil. The grass was uninjured. This treatment 

 seemed j)romising and on the 8th of June, under direction of this Divis- 

 ion, Mr. Cogan treated the entire area with kerosene emulsion diluted 

 fifteen times. For this purpose 15 gallons of emulsion were prepared, 

 requiring 10 gallons of oil, and about 5 pounds of soap were used. This 

 would give some 300 gallons of diluted wash. This was applied liberally 

 to the soil, which was for some days kept freely soaked with water. 



June 11 I visited the grounds again. The grubs over the whole area 

 had turned down into the soil and seemed sick ; when dug out were so 

 weak they could scarcely crawl. 



No dead ones were found. The green grass had not been injured by 

 the application. Mr. Cogan was requested to keep the soil well watered 

 and observe what further results followed. 



On June 27 the grounds were again visited. The grass which was 

 not killed by the grubs had recovered very much ; where grass had been 

 killed wild grass and weeds are growing in. The grubs are still in the 



*The '' White Grubs" in this instance are larvse of AllorMna nitida. See note by 

 C. V. Riley in Le Baron's fourth report as State Entomologist of Illinois, p. 90. 

 See also note on the habits of these larvre in Washington, by L. O. Howard, Canadian 

 Entomologist, 1879, p. 200; also in American Naturalist, 1882, p 411. 



