436 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



Forty ears were used in this experiment: ears Nos. 1-10 were punc- 

 tured with a clean, heat steriHzed, needle; Nos, 11-20 were punctured 

 with a needle moistened with clean tap water; Nos. 21-30 were not 

 punctured but were simply moistened on the outside of the kernels 

 with a solution of the disease, and Nos. 31-40 were punctured with 

 needles infected with the disease. In puncturing the kernels the husk 

 was pulled back from part of the ear and a single row of kernels punc- 

 tured. Sterile tissue paper was then placed over the exposed kernels 

 and the husk replaced and fastened with a rubber band. The only 

 case wherein we got infection was in the last series of ten ears, those 

 infected by puncturing the epidermis of the kernels with infected 

 needles. The day following the infection, a characteristic yellow dis- 

 coloration was noticed around the point of infection in every kernel 

 in the row infected. The second day following infection, the kernels 

 were generally discolored and on the third day the epidermis of many 

 had ruptured with the characteristic viscid exudations. This seemed 

 to indicate that it was necessary that this disease should gain access to 

 the kernel by means other than air-borne spores alighting upon the ex- 

 posed tips of the ears, which was the theory advanced by several packers 

 in this region, and that it was transmissible by subcutaneous injection. 

 The only natural methods that suggested themselves to the writer, 

 were a root infection of the plant by which the disease gained access to 

 the corn through the fibro vascular system, or an infection caused by 

 the injury of the kernel by some insect which had previously been in- 

 fected with the disease. A careful search was made in many of the 

 worst infested fields and the only insect which seemed at all likely to 

 be able to gain access to the corn within the husk was the small Heterop- 

 teron, Triphleps insidiosus. Large numbers of these insects were found 

 in the fields where the disease was worst. They were in the silk, under 

 the husk, and in the litter about the bases of the plants. As the season 

 was then well advanced and the corn crop was pretty well harvested, 

 further field experiments with the insect were not possible. Since 

 that time we have received no complaints of this disease attacking 

 field corn and other problems have engrossed our time. Most of these 

 diseases caused by Diplodia and Fusarium are supposed to pass the 

 winter in the plant refuse and on the ground in the fields and thus to 

 reinoculate the ensuing year's crop. 



In 1914 Messrs. H. Garman and H. H. Jewett^ published a short 

 account of Triphleps insidiosus as a beneficial insect feeding on the 

 eggs of corn-ear worm, Chloridea ohsoleta. In this account they very 

 minutely record their data on the egg laying of this insect. During 

 the latter part of August the eggs are laid in the corn silk and hatch 



iKy. Agri. Exp. Sta., Bui. 187, p. 587, 



