EXPERIMENT STATION BULLETINS 185 



them are briglitly colored. The feeding habits of the difl'erent kinds of insects in this 

 class are very much alike, except that each species usually is restricted to a limited 

 number of food-plants. They are provided with sharp, sucking beaks, whicli extract 

 the sap and juices from trees and plants of all sorts. Some of them work on grasses. 

 The effect is the gradual decline of the plant attacked. If the plant is of any size, 

 this injury may go on and stop at any point, depending on the amount of food ex- 

 tracted and the damage due to the wounds of the beaks. Unless the insects are seen 

 to be present, the exact cause of the injury is often difficult to locate, as the punctures 

 are very small and the wounds are not conspicuous. 



Manv' of these small sucking insects are to be found in the Upper Peninsula as well 

 as in the Lower, and in spite of the fact that vegetation is vigorous, the tax levied by 

 these apparently insignilicant insects is quite a heavy one. The remedy is the same 

 for all — spraying with a strong tobacco extract when they are seen to be at work, and 

 the destruction of rubbish in the winter time. 



While probably they never can be exterminated by the methods advised, beneficial 

 results certainly will follow the practice if it is conscientiously carried out from 

 year to year. Insects of this class, most of them, pass the winter in rubbish and 

 in out of the way places. Now, the destruction of all rubbish after the cold weather 

 has once set in will do away with great numbers of the insects. This is especially 

 true in towns and in regions not wooded. In new clearings many of the insects will 

 resort to the woods for shelter, and of course cannot be readied, but the general 

 practice of clean culture Avill prove of noticeable and lasting benefit. 



THE CAXOE-BIRCH COCCID. 

 (Xylococcus hetulce, Hub. & Pergande.) 



This interesting scale-insect was found at Munising and at Harbor Springs. It 

 was first found by Messrs. Hubbard and Schwarz at Michipicotcn and near :\Iarquette, 

 both on Lake Superior. The insect works in the bark of canoe-birch, making cavities 

 in the bark and splitting the layers so that it becomes useless for the purpose of canoe 

 making. Mr. Hubbard says:* "In 1870. when Mr. Schwarz and I visited the north 

 shore of the lake at Michipicotcn river, we were told that the Indians were obliged 

 to go sixty miles back into the interior in order to find sheets of bark of sufficient size 

 for the construction of canoes." The first indication of its presence that attracts 

 the eye is the roughenetl surface of the bark, especially near tlie ground. On closer 

 examination, it is possible to find very delicate, glassy filaments projecting from cavi- 

 ties in the bark. These are waxy in nature and protrude from about the caudal ex- 

 tremity of the coccid. Very littie time was available to search for these interesting 

 insects, but they were seen to be quite plentiful at Pictured Rocks, on a few isolated 

 trees. 



FALL ARMY-WORM. 



(Laphygma fnifjipcrda, S. & A.) 



A curious change of habit, which, it is hoped, will not prove more than temporary, 

 was observed in this species. Ordinarily the fall army-worm works like a fall cut- 

 worm, feeding on many ditterent crops and on some uncultivated plants. Tliis year, 

 however, it attacked the corn crop in large numbers, entering the ear and l)urro\ving 

 into the kernels both when they were in the milk and later, just as is done Ity the 

 regular corn-worm {HcUothus armifler). The corn at the Station grounds was 

 badly aficcted. Specimens were obtained for rearing i)urposes and placed in cages 

 in the laboratory. From this material a single motli emerged on October 2."). the 

 larv£B having been received fresh from Mr. Geismar on September 10. This moth, 

 together with a pair of ]arva». was sent to Professor J. B. Smith, of the New Jersey 

 Experiment Station, who kindly determined it for me as Laiiliyynia fnigipcrda. 



IIKMKUIKS. 



In regard to remedial measures. Dr. J. B. Smith saysif ''Tliore are always two and 

 sometimes three or more broods in the course of the year, and- in favorable seasons 

 these become successively more numerous, so that the lale fall brood ]irovcs the 



►Hullptin IS. Npw Sprips. Dppt. of .\griciilture, Division of I'.iitomology. 

 ri;conomic Entomology, p. i'O". 



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