50 Tllli APPLE LEAF HOPPER 



This wonderful fecundity on the part of the Green Bug has a most 

 serious aspect to farmers who live in the South, where reproduction 

 of grain aphids begins very early in the season. If the cold winters 

 of JNIinnesota could be eliminated our grain fields would be in great 

 danger. 



\A'e have yet to find the dates and location of egg laying of M. 

 grainiria in the fall, evidently quite late, for on Dec. 10, 1907, we found 

 winged and wingless females and young on winter wheat, an indica- 

 tion that the egg-laying forms of this species appear very late in the 

 season. The temperature had been down as low as 10° above zero, and 

 these individual lice had been covered with snow. 



THE EUROPEAN GRAIN LOUSE. 



Sif'liocoryiiac azuviac Fab. 



'i'his insect common on our grain, also believed to be the same 

 found on the ap])le under another name ("Green Aphis") was dis- 

 cussed on pages 15 aixl 16 of the report and bulletin previously al- 

 luded to. It was found afi:'ecting leaves and young stems of wdieat. 

 oats, barley and rye. and later found on the heads of the same grains. 

 It was also found on pigeon grass and volunteer grains, and in the 

 fall on winter wheat and rye. In 1907 it was found pretty generally 

 distributed over tlie stale. 



In 1*)08 it was found as follows: 



July 5, ]\Iora, on quack grass, where, by the wa\-, it was attacked 

 by a small red mite. July 10th it was found on oats at St. Anthony 

 Park. On July 19 at the same place "on apple, curling the leaves of 

 the new growth and doing considerable damage." 



July 27. I5reckenridge: Young of this species found on volun- 

 teer oats, inside the leaf sheaths, and on the 28th at Moorhead on 

 volunteer oats in stubble inside the unopened terminal leaves. 



The following table shows insectary work on this species, begin- 

 ning January 10th. It is interesting to note that in this series there 

 was no intervening egg stage; in other words, the generations were 

 produced continuously with no break from the insects of the preced- 

 ing year. Further, the insects through which these generations came 

 had been sul)jected in the cold room of the insectary, to zero tempera- 

 ture during the last of December and first part of fanuary. 



