84 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



ANTS, GREEN FLY, AND SCALE. 



By Doctor Bonavia, F.R.H.S. 



" Indian Planting and Gardening " of February 14, 1903, gives some 

 curious information about ants and aphides, quoted from a paper by 

 Mr. M. Chittenden, Assistant Entomologist of the United States 

 Department of Agriculture. 



It had been known that ants suck up the sweet fluid exuded by two 

 minute tubes at the end of the body of the aphis, and that ants had 

 some means of inducing the aphis to give forth this sweet fluid more 

 abundantly. But Mr. Chittenden appears to have gained some further 

 knowledge regarding the curious relationship between the ant and the 

 aphis. He states that in return for the services that the aphis renders 

 to the ant the latter repays it handsomely. It not only guards and 

 protects the helpless aphis when ' on the plant, but it gathers the eggs of 

 the aphis and takes care of them in its own subterranean nests, to be 

 distributed in due season on the tender parts of appropriate plants, 

 whereby not only the newly hatched aphis is benefited, but the ant 

 obtains, as it were, a sort of milch-cow to provide itself with food and 

 drink ! 



If all this is true, it is a very fascinating and pretty discovery, and 

 I have been much interested in reading it, because two years ago I con- 

 ceived a suspicion that ants had something to do with the dissemination 

 of aphides on plants. My suspicion was aroused in this way. I had just 

 had a warm house erected and put therein some plants. A few days 

 after I detected a minute larval green fly on one of the tender shoots. 

 A small black ant was not far off, moving leisurely, as if it were 

 unemployed. I wondered how this baby green fly had got there so soon 

 after the house was erected and the plants put into it. The vicinity of 

 the ant led me to suspect that the latter had something to do with the 

 young aphis being there. I have often watched ants moving about the 

 stem and leaves of plants to see if I could catch them red-handed at this 

 sort of work ; but as yet I have not succeeded in doing so. I fancy ants 

 do a great deal of their work at night. They are accustomed to work in 

 the dark in their underground tunnels. 



Here, then, there appears to be a remarkable symbiosis between the 

 ant and the aphis which was not suspected before. The discoverer of 

 this interesting phenomenon says : " In frequent cases the ants com- 

 pensate the plant-lice for the food which they derive, not alone by 

 guarding the lice and protecting them from natural enemies, but by 

 caring for their progeny as well as for their own, even gathering the eggs 

 of the lice and taking them into their own subterranean nests, keeping 

 them there over winter, and when warm weather sets in in spring 

 returning them to the field and placing them on their appropriate food 

 plants. In fact the relationship of these creatures is such that it is 

 difficult to determine which is the benefactor and which the beneficiary. 



