260 EXPERIMENT STATION RECORD. [Vol.37 



Aside from its value as a means of bringing fish to tlie pools and providing 

 means of quickly draining some areas, ditching is of importance in bringing 

 salt water to increase the salinity of permanent pools, thus rendering them 

 salt enough in some cases to retard and In some cases to check completely the 

 development of the mosquitoes. It is suggested that there is a possibility that 

 the incoming tide may drown the mosquito larva? by the rise and fall of its 

 waves as they advance. 



See also a previous note (E. S. R., 36, p. 25.5). 



A biological study of the more important of the fish enemies of the salt- 

 marsh mosquitoes, F. E. Chidester (A' etc Jarsey Stas. Bui. 300 (1916), pp. 

 3-16. pi. 1, figs. 2). — This is a report of studies commenced September 19, 1914, 

 and carried on for more than a year. 



The barred killifish {Fundulus heteroclitus) was found to be the greatest 

 natural enemy of the salt-mar.^h mosquito and also to eat many green-head 

 flies. " F. heteroclitus captures larva^, pupre, and adults of the mosquito, eat- 

 ing as many as 50 a day and killing many more. The vast hordes of fishes 

 which migrate to the shallows and even into almost fresh water render the 

 species especially formidable. The number of enemies of the mosquito which 

 are eaten by F. heteroclitus is negligible and is more than compensated for by 

 the great preponderance of mosquitoes in the diet of the fish. The ease with 

 which Fundulus may be artificially fertilized and the remarkable vigor and 

 resistance of the j'oung embryos make the stocking of pools and streams with 

 this species a simple matter." 



A list of 19 references to the literature relating to the subject Is appended. 



Results of ten years of experimental wheat sowing to escape the Hessian 

 fly, G. A. Dean (Jonr. Econ. Ent., 10 (1917), No. 1, pp. 1^6-162. fig. i).— This 

 is a summary of work conducted at the Kan.sas Experiment Station, much of 

 which is presented in tabular form. In that State the most important steps 

 in the control of the Hessian fly are (1) enrly, deep plowing of the stubble. 

 (2) proper preparation of the .seed bed, (3) destruction of all volunteer wheat, 

 (4) delay in .sowing umil the fly-free date, and (5) cooperation. 



Wind as a factor in the dispersion of the Hessian fly, J. W. McCoi.loch 

 (Jour. Econ. Ent., 10 (1917), No. 1, pp. 162-170, fig. i).— This deals with obser- 

 vations made at the Kansas Experiment Station which show that wind is an 

 important factor in the distribution of the Hessian fly. At the place where 

 many of the observations were made the flies were being carried up over the 

 hills and into the wheat fields lying on the other side in the Blue River Valley. 

 The fact that the flies were uninjured on reaching the screens would indicate 

 that they could be carried much greater distances. The relatively large num- 

 ber of llios caught on the small screen area at 2 miles is indicative of the 

 possible magnitude of their flights. 



This work shows that cooperation must be practiced over large areas and 

 that the individual grower can not be promised immunity from injury even 

 if he does prepare a good seed bed and plants late. All stubble fields and 

 volunteer wheat fields must be plowed under early in the fall, as they are the 

 greatest sources of infestation. 



The protection of dairy cattle from flies, E. N. Cory (Jour. Econ. Ent., 10 

 (1917). No. 1, pp. 111-114)- — Several complaints that butter made at the Mary- 

 land Experiment Station was very perceptibly tainted with the coal-tar odor 

 where proprietary coal-tar products had been used in protecting cattle from 

 flies led to the preparation of a pine-tar creosote emulsion which left no such 

 taint. This was made by dissolving § lb. of caustic soda, 9S per cent pure, 

 in a known quantity of water for every gallon of pine-tar creosote, and then 

 diluting with cold water to the desired strength. 



