110 



PAPERS ON CEREAL AND FORAGE INSECTS. 



Massachusetts, Connecticut, Rhode Island, New York, New Jersey, 

 Delaware, Maryland, West Virginia, Ohio, and Illinois. 



Mr. J. A. Kreutzberg, writing from Chicago, 111., September 9, 

 1908, says: 



From 500 to 1,000 plants grown from seed early every year in the hotbed, 

 and in due time transplanted in the open ground, rarely more than one-third 

 survive and pull through to full growth and beauty. The trouble appears to 

 be a small green louse which looks like the aphis which infests the rose bushes, 

 lodging in the roots, forming large colonies in them, and working their way up 

 in the plants to the surface of the ground. Some of the plants are blighted as 

 soon as they are set in the open ground, some later, and some when the plants 

 are in full bloom. The moment that the plants are attacked by these parasites 

 they show it by turning yellow and wilting down to the ground. 



In a later letter, September 15, 1908, he says: 



I this morning pulled up three aster plants which were in full bloom, vet 

 showed the taint of the ravages of the aphis, which apparently did not attack 

 the plant until quite recently. In looking over my aster field this morning 

 I find that nearly every plant is affected, which was conclusive proof to me that 

 these little pests begin their attack during all stages of growth of the plants. 

 Some are attacked immediately after transplanting to the open ground, others 

 a little later on. and some that seem to have strength enough to pull through 

 and are in bloom are attacked after the bushes are loaded with flowers. These 

 three plants that I pulled today were loaded with the insects, but of a different 

 color than I have found them heretofore, but apparently the same genus. 



The other reports are much the same. The aphides apparently at- 

 tack the asters as soon as they are set out in the open and feed on 

 them till the sexual forms appear and the eggs are laid in the fall. 

 The correspondents ofren report that the aphides are attended by 

 ants, but only one species has been taken and identified. Lasius alie- 

 nus Forst was sent to the Bureau by Mr. C. R. Cranston from Provi- 

 dence, R. I., with the following information : 



Just as the [aster] buds begin to form, the leaves all turn yellow and the 

 plant never blooms. On pulling some up I found that ants had taken green 

 plant lice under ground to suck the sap from the roots. 



It should be easy to keep the asters free from this pest if the fol- 

 lowing precautions are taken : Choose for the aster bed ground that 

 has not grown asters or corn for the past year. Free this ground 

 from the wild food plants of this species some time during August. 

 Then, if there is no crop on the ground, it may be cultivated, covered 

 with manure, and left till next spring. The only way for the aphis 

 to reach the plants on this ground would be for the winged migrants 

 to fty to the plants and then be captured and taken to the roots by 

 ants. It is extremely improbable that those reaching the plants in 

 this way could increase in numbers fast enough to do serious injury. 

 In fact, if the asters are planted in ground which has not grown 

 asters or corn the past year, and which is not located near a field of 



