160 FORTT-SECOND REPORT ON TEE StATE MuSEUM. [18] 



planted alternately in one row, and in the next all beans, thus making 

 the melons six feet apart each way. The string beans were out of the 

 way in time for the melons to occupy the ground. Previous to adopt- 

 ing this method, it had been found necessary to go the rounds every 

 morning before sunrise and kill the beetles, and even then they could 

 not be kept under control. 



Gas-lime for the Woolly-aphis. 

 It appears from Bulletin No. 55 of the University Experiment 

 Station at San Francisco, Cal., that the experiments made with gas- 

 lime for destroying the woolly- 

 aphis of the apple tree, 

 Schizoneura lanigera (Hausm.), 

 the root form of which 

 is represented in Fig. 2, have 

 shown the value of this insec- 

 ticide for the destruction of a 

 pest, hitherto almost beyond 



our control. In the experi- 

 PiG. 2. —The apple-root plant-louse, Sghi- , i i . /■ 



zoNEUEA lanigeea; «. the knotted root; f^andc, ^^^nts made about four years 

 wingless and winged larval forms. ^gO, an application of ten 



pounds of the lime to a tree had killed the aphis infesting the 

 roots, but at the same time, some of the trees standing on 

 shallow soil had been killed by the application, and the general 

 results were therefore reported as not satisfactory, the more so, as the 

 aphis was subsequently seen descending to the roots. Since that time 

 it has been found that only the badly located or weak trees had been 

 killed, and that the aphis had not reinfested the roots, but existed 

 only at the surface of the ground. Later experiments with the gas- 

 lime differently applied, gave very satisfactory results, in entirely 

 arresting the aphis attack, without injury to the trees. Instead of 

 removing the soil and putting the gas-lime in close contact with the 

 tree, as done the first time to the corrosion of the bark, about a 

 shovelful and a half (two or three pounds) in a dry state were dis- 

 tributed over the surface in a radius of four feet, trusting to the rain 

 to carry it into the soil. A few shovelfuls of fresh ashes were piled 

 close about the trunk to prevent the aphis from congregating on the 

 crown. 



How TO Kill the Apple-tree Aphis. 



A correspondent had asked for an effectual cure for green lice or 

 aphides on the leaves of apple-trees. He had used kerosene, tobacco 

 and strong soap-wash, each of which had killed the lice, but others 

 appeared very soon in apparently greater numbers than at first, 



