456 EXPERIMENT STATION EECOED. 



The larvicidal action of plant material containing saponin (corn cockle 

 [Agrostemma githago] and agave [Agave lecheguilla~\) and alkaloids (blackleaf 

 40, larkspur [Delphinium], stramonium [Datura stramonium'], and hellebore 

 [Veratruni alhum and Y. viride]) was tested. Other plant material tested 

 included oxeye daisy (Chrusanthemum leucanthemum) and pyrethrum (0. 

 cinerariwfoUum) . Powdered hellebore proved the most efficient and practical 

 of all the substances tested. 



" Powdered hellebore, using 0.5 lb. to 10 gal. of water and applying this to 

 8 bu. of manure, is also an effective larvicide and exerts no injurious action 

 on the fertilizing value of the manure as detennined by bacteriological and 

 chemical analyses, and no injurious action on plants has been detected in any 

 of the field tests. Hellebore is used as an insecticide and is obtainable in most 

 cities and agricultural districts. The cost of this treatment is 0.60 ct. per 

 bushel of manure." 



Borax, which was shown in the previous bulletin to be an effective larvicide, 

 is obtainable in all parts of the country, and the cost of treating manure at 

 the rate of 0.62 lb. of borax per 8 bu. is 0.42 ct. per bushel. " While borax 

 may be applied to manure at the foregoing rate and the treated manure may 

 be added to the soil at the rate of 15 tons to the acre without injuring vegeta- 

 tion, nevertheless excessive Quantities of borax may be applied to manure 

 through carelessness, and injury to vegetation may in consequence result. In 

 the light of this year's experiments it seems advisable to recommend borax as 

 a larvicide for the treatment of outhouses, refuse piles, and all other places 

 where flies may deposit eggs. However, on account of the possible carelessness 

 previously mentioned, and because large quantities of manure are sometimes 

 used by truck growers, it seems best to guard against possible injui-y to vege- 

 tation by recommending powdered hellebore for the treatment of manure, 

 since no injury can arise from the use of excessive quantities, as it is entirely 

 decomposed in the course of the fermentation of the manure." 



Plague and plague-like disease, — A report on their transmission by 

 Stomoxys calcitrans and Musca domestica, N. B. Wayson (Pw&. Health Rpts. 

 [U. S.], 29 (WW, No. 51, pp. 3390^393).— The author reports that the trans- 

 mission of Bacterium tuJarense by bites of stable flies occurs, apparently, only 

 from those animals having an advanced stage of the bacteremia. In two experi- 

 ments where stable flies were allowed to bite the infected animal four times and 

 the healthy animal four times death did not occur, but in two experiments where 

 stable flies were allowed to bite an infected animal eight times and to bite a 

 healthy animal eight times death resulted. Experiments are being conducted to 

 determine the length of time that flies remain infective, the results thus far 

 having been negative after 24 hours from the time of feeding. House flies fed 

 on 48-hour-old viscera of an animal dead of the disease were found to convey the 

 infection. 



The cranberry rootworm, H. B. Scammell (C/. S. Dept. Agr. Bui. 263 (1915), 

 pp. 8, pis. 2). — The cranberry rootworm (Rhahdopterus picipes) Is the larva of 

 a small brown chrysomelid beetle which has recently become a source of injury 

 to the cranberry in New Jersey. Observations continued through a period of 

 two years indicate that at the present time it is not a pest of prime importance 

 on cranberry bogs, and that its ravages are not to be compared in severity to 

 those of the cranberry girdler (Cramlnis hortuellus) . 



The chief injury is caused by the feeding of the larviB on the roots and runners 

 where the latter come in contact with the ground. As a rule only the bark is? 

 eaten from the large and secondary roots, the wood occasionally being attacked 

 while the flbrous roots, which are so numerous as to form a dense mat an inch 

 or more in thickness, are completely devoured. The beetles feed on the foliage 



