32 MONTANA EXPERIMENT STATION 



experience in Montana it is not expected that the webworm will 

 be more than usually abundant in 1919. 



THE FALSE CHINCH BUG 

 Again and again we have had reports of the supposed occurrence 

 of the chinch bug {Blissus leucopterus Say) in various parts of 

 Montana but in nearly every case the insect concerned has been 

 the false chinch bug (J^ysius ericae Schill). This very common 

 msect, a drawing of which appears on the cover page of this report, 

 in size and habits resembles somewhat the very destructive true 

 chinch bug which we believe does not occur in Montana except 

 scatteringly in a few counties in north central Montana where it 

 has been present several years to our knowledge but without being 

 very injurious. 



The false chinch bug was injurious mainly to garden plants 

 which were attacked by great numbers of the insects clustering on 

 the terminal growth and sucking out the juices. Some measure of 

 alarm was felt by farmers as it was feared that extensive damage 

 to grain and corn might result from the excessive numbers of the 

 lalse chinch bug. No damage was done to field crops, however, so 

 far as we can judge from the reports that reached us. 



According to Milliken, ("Nysius ericae. The False Chinch Bug," 

 in Journal of Agricultural Research, Vol. XIII, No. 11, p. 571, 1918) 

 there are in Kansas six or seven generations of this insect per year. 

 This writer found that about a month is required to complete one 

 life cycle at a temperature of 79.78 degrees Fahrenheit. We cannot 

 state definitely how many generations there are in Montana but it 

 is clear there are several. These insects multiply with rapidity and 

 il is not surprising that such great numbers appear. We have often 

 found them congregated in large numbers on and under weeds 

 during hot days. The carpet w^eed, or purslane, is a favorite food 

 and shelter and often touching such a weed with the foot will cause 

 hundreds of these small insects to scurry away in all direc- 

 tions. Mr. J. R. Parker, while traveling in Flathead County on 

 August 5, 1910, found various plants, including potatoes, carrots, 

 raspberry bushes, turnips, and strawberry plants being damaged by 

 great numbers of these insects which clustered on the growing ter- 

 minals, causing them to wilt. Potatoes were particularly in danger 

 as the adults had settled upon them in great numbers. Beets are 



