U. S. D. A., B. E. Bui. G4, Part IX. I«ued October 17, 1910. 



SOME MISCELLANEOUS RESULTS OF THE WORK 

 OF THE BUREAU OF EXTOMOLOGY-IX. 



NOTES ON A COLORADO ANT. 



{Formica cinereoruf.barbis Forel.) 



By H. 0. Marsh. 

 Agent and Expert. 



INTRODUCTION. 



A medium-sized ant, known scientifically as Formica cinereorufi- 

 tarbis Forel, is one of the most common species occurring in the vicin- 

 ity of Rocky Ford. Colo. The nests which it constructs along the 

 fences and irrigation ditches are mounded up very little or not at all, 

 but often cover a considerable area. Sometimes these nests are 3 or 

 4 feet in length by 2 or 3 feet in width, and they always have several 

 openings. 



During the growing season this species of ant is always to be 

 found in attendance on various species of aphides or plant lice. 

 During the summer of 1909 it was most commonlv found together 

 with the melon aphis (Aphis gossypii Glov.) on cucurbits, and with 

 Chaitophorus populicola Thos. on cottonwood. The ants were also 

 observed attending a species of Membracidae on alfalfa, and late in 

 the season after the leaves had fallen great numbers were found 

 clustered and feeding upon crushed overripe cantaloupes, sometimes 

 out in the field 25 yards from any ant nests. 



As the ants were almost invariably to be found on aphis-infested 

 cantaloupe vines, many of the growers are of the opinion that they 

 are responsible, in part at least, for the spread of the aphides from 

 on vine to another. There is also a rather general idea that the 

 ants take the aphides into their nests in the fall, protect them through- 

 out the winter, and then bring them out in the spring and put them 

 upon the plants. 



INJURIOUS HABITS. 



There appears to be but little foundation for believing that the 

 ants harbor the melon aphis during the winter, ami after careful 

 watching the writer has never seen any aphides being carried into the 



