1900] 



ENTOMOLOGICAL SOCIETY. 



81 



too much and thus be pufied out unnaturally. When the skin is ready for the oven a 

 pair of forceps will be found a means of help in inserting the inflating-tube into the vent. 

 After the larval skin is thoroughly dried care should be taken in removing it from 

 the inflating-tube. This can easily be done in most owes by simply forcing the skin ofi 

 the tube by means of the thumbnail of the right httnd. The caterpillars may then be 

 mounted on a piece of fine wire wound tightly around the pin five or six times, the 

 lower end of the wiie being neatly cut ofi. The portion on which the larva is to be 

 mounted may be cut according to the size of the caterpiliar. Any good cement, such as 

 that used for repairing insects, may be employed to fasten the blown skin to the wire. 



NOTES ON TWO LONGICORN BEETLES AFFECTING GROWING NURS- 

 ERY STOCK. 



By F. M. Webster, Wooster, 0. 



With the rapid changes in the flora of the country, brought about by advance in our 

 civilization, there must of necessity come changes in the. habits of such of the animal life 

 as is dependent upon this flora for their food supply. Nor do the influences stop here, 

 for it is frequently not difficult to observe the eflfects of such changes even in the parasitic 

 enemies of these animals. 



Hardly a season passes but that some old and well known insect exhibits some 

 characteristic not before observed. Sometimes this, to us, new phase of its sociology 

 may not again be noticed for years, or it may continue and indeed increase to such an 

 extent as to become a normal characteristic of the species. As instances of this change 

 of habit, the adult of the Western Corn Root Worm, Diabrotica longicornis, was former- 

 ly known only as a green beetle found on the blossoms of thistle and golden-rod ; where- 

 as, now, it swarms over the corn fields of the middle West in myriads, and the larvae are 

 one of the worst pests of the corn field. It is only within the last three years that the 

 two ground beetles, Harpalus caliginosus, and II. pennsylvanicus, have come into 

 prominence as strawberry insects. 



The first species here 

 considered is the coated 

 Saperda, or the Linden 

 borer, Saperda vestita, Say 

 (Fig. 42) described in 1824, 

 from specimens taken near 

 the southern extremity of 

 Lake Michigan, but was 

 also known at that time 

 to occur in Pennsylvania. 

 Though common, the insect 

 does not appear to have 

 anywhere become seriously 

 destructive though it was 

 well known to Harris as 

 (arly as 1832 and said by 

 him to have been destruc- 

 tive to the European Lin- 

 den in Cambridge, Massa- 

 chusetts, in 1843 and 1844. 



Dr. Paul Smith, in a letter written May, 1844, quoted by Dr. Harris in his "Insects 

 Injurious to Vegetation " gave an account of an attack upon European Linden trees in 

 Washington and Independence Squares, Philadelphia. The trees were attacked about 

 seven years before but within two years it had been found necessary to cut down forty- 

 seven of these European Lindens in Washington Square alone. The American Lindens 

 were also injured but apparently to a less degree. One of the Lindens mentioned by Dr. 

 Harris was very large, the trunk measuring 8 feet, 5 inches in circumference 5 feet from 

 the ground. A strip of bark two feet wide at the bottom, and extending to the top of 

 6 EN. 



1 



Fig. 42.- 



2 3 



-Saperda vestita Say ; 1, larva ; 2, pupa'; 3, adult ; 

 all slightly enlarged. 



