CARBON DISULrHID AS AN INSECTICIDE. 15 



situations by furnisiiiiig ^vann places for the nesting of the ants. For 

 the winter, trap boxes 2 bj' 2 b,y 3 feet in size were filled with leaves, 

 cotton seed and straw or other porous material. These were placed 

 in the open about the 1st of October, so that the contents might be 

 wet by the rains and then become warm through the process of decay. 

 This material proved so attractive to the ants that practically all 

 colonies within a radius of 30 or 40 yards would take up their abode 

 in it as cool weather came on. In a single trap of this kind it was 

 estimated that more than 1,000 fertile queens were present. In mid- 

 winter the cracks in the box were closed tightly, the top covered with 

 a waterproof canvas, and carbon disulphid applied, so that all ants 

 were destroyed at once. This appears to be one of the most econom- 

 ical and effective methods for controlling the Argentine ant. 



In the destruction of colonies of the agricultural ants which are 

 very common in the southwestern States carbon disulphid treatment 

 has given most satisfactory results.^ The liquid is evaporated under 

 an airtight, galvanized-iron tub, which is inverted over the entrances 

 to the colony. The fumigation is begun when the gatew'ays to the 

 nest are open, thus permitting the vapor to flow into the tunnels and 

 penetrate to the low^est chambers in the nest. If other openings occur 

 that can not be covered Avith the tub at one time, thej^ should all be 

 closed by piling dirt around the tub. One to three ounces of liquid 

 should be used, depending upon the apparent size of the nest, and the 

 tub allowed to stand for five or six hours. By this time all ants will 

 have been killed, and the tubs may be moved to other colonies. 



Where ants infest the surface soil generally throughout a consider- 

 able area, holes not more than 18 inches apart and several inches 

 deep may be made with a stick or iron bar, an ounce of disulphid 

 poured into each, and the holes closed immediately. After the whole 

 area has been treated the ground should be wet thoroughly or covered 

 Avith waterproofed canvas, or paper, or wet blankets, to aid in con- 

 fining the gas. 



USE OF CARBON DISULPHID AGAINST WHITE GRUBS AND MOLE 

 CRICKETS. 



White grubs, which are the young of the so-called May beetles or 

 June beetles, occur throughout the United States and frequently are 

 so abundant as to demand treatment. Their period of development 

 is long, extending over two or three years, and during this period 

 they are feeding upon the roots of plants. Mole crickets are most 

 abundant in the Southern States and in the islands in the Gulf of 

 Mexico, and they produce a full generation each year. Both of these 



' Ileadlee, T. J., and Dean, Geo. A. The mound-lmilding prairie ant. Kaus. Agr. Col. 

 Exp. Sta. Bui. 154, p. 178-180. 1908. 



