18 



In fields of sod corn near Peru, Illinois, I found, as late as July 

 1, 1883, many wireworras devouring the roots of corn and penetrat- 

 ing the stems just above the root, about six per cent, of the stalks 

 in one of the fields having been killed in this way. Sometimes two 

 or three of these larvie were found boring through a single stem. 

 The wireworms here collected agree in every particular with those 

 described in the Canadian Entomologist, by Dr. Horn, the beetles 

 bred from which were identified by Inm as Agrlotes mancus* This 

 species is readily distinguished from Melanotus by the cylindrical, 

 blunt terminal segment, marked above by a large black circular 

 pore upon each side of the base. In this same field occurred the 

 wireworm doubtfully identified by Dr. Fitch as our common Melan- 

 otus comiimiiis,\—'dn identification which I am very much inclined to 

 consider correct because, as noticed above, we bred this species, 

 last year, from corn wireworms. 



Believing it to be quite within the limits of a reasonable probability 

 that apparatus may be invented for the rapid and economical ap- 

 plication of insecticides to hills of growing corn, I instituted, last 

 June, some experiments upon wireworms with a view to determining 

 what insecticides, if any, would be effective against them. Placing 

 individual larvae in boxes containing fifteen cubic inches of earth, 

 a dram of kerosene emulsion (half kerosene) was jDOured over the 

 earth without effect upon the larvie. A repetition of this experi- 

 ment gave the same result, but a dram of pure kerosene applied in 

 this manner promptly killed the wireworms. Pyrethrum thoroughly 

 applied directly to the wireworms seemingly did them no harm. 

 Sprouting corn treated with water containing suspended Paris green 

 was not attacked by wireworms placed in the earth with it, but 

 neither were the latter themselves injured. Sprouting corn placed 

 in earth with which Paris green had been mixed failed to grow, 

 but was not attacked by the wireworras, these remaining alive and 

 active. 



To determine the effect of treating seed corn with arsenic previous 

 to planting, moistened kernels were rolled in powdered arsenic and 

 allowed to dry, others at the same time being dampened with water 

 holding Paris green in suspension. Only three kernels, out of a possi- 

 ble one hundred, grew in the first lot and two in the second, as com- 

 pared with the check corn planted at the same time. Later a hundred 

 grains of corn moistened with water and rolled in a mixture of 

 Paris green and plaster of Paris — one part to fifty — were planted in 

 comparison with another hundred grains not so treated, both lots 

 of corn being planted in separate boxes and similarly treated. For- 

 ty-four kernels grew in the poisoned boxes, and forty-eight in the 

 check, both lots appearing above ground simultaneously and grow- 

 ing for a month together without important difference. 



From the foregoing we may infer the practical inefficiency of 

 both pyrethrum and kerosene emulsion as a protection against these 

 insects, and the doubtful efticiency of Paris green. This last de- 

 serves, however, further experiment. 



♦ Canadian Entomologist, Vol. IV, p. 3. 



+ Trans. N. Y. St. Agnciiltural Soc, ISi 6. p. 520. 



