lO NEW YORK STATE MUSEUM 



semitransparent patches in the foliage. These latter soon dry 

 and turn brown. 



There are two and occasionally three generations of this de- 

 structive insect in the latitude of Albany, the number depending 

 to a considerable extent upon the availability of suitable food. 

 The grubs complete their growth in froim fifteen to twenty days, 

 descending limbs and trunk to a great extent in search of some 

 shelter under which to pupate. Seven days are spent in this 

 latter state in warm July weather, while in September it is ex- 

 tended to twelve and in October to twenty-four days. The grubs 

 of the first brood usually forsake the trees in Albany by the last 

 of June or early in July, and beetles belonging to the second 

 generation may begin depositing eggs about the middle of July, 

 and from then to late in autumn it is generally possible to find 

 this insect in all stages in some part of Albany. The beetles of 

 the second brood are naturally attracted to fresh foliage and 

 consequently more eggs are usually deposited on trees which 

 have been defoliated earlier in the season than upon others. 



Badly infested trees are therefore very likely to lose two crops 

 of leaves in a season and may possibly have their third seriously 

 marred by this pest. The second brood of grubs completes its 

 growth about the middle of August, beetles appearing the latter 

 part of the month, and if there is an abundant supply of fresh 

 leaves, a third generation may .appear in considerable numbers. 

 This last brood more frequently occurs in near-by trees which 

 have not been severely injured earlier in the season. 



Natural enemies. This leaf feeder is subject to attack by a 

 number of natural enemies, most of which, however, are of com- 

 paratively little importance in keeping it in check. The common 

 garden toad will devour many beetles, and the much despised 

 English sparrow also feeds upon these insects to- some extent. 

 Several predaceous insects prey upon this pest to a certain 

 degree. 



Preventive measures. There are measures of considerable 

 value in the prevention of insect depredations, and there is no 

 reason why such should not be applied to the shade tree problem. 

 It is a mistake to have half to three-fourths of all the shade 

 trees in a city or village one species, especially if mostly on 

 contiguous streets. This is true of many localities where 

 the elm leaf beetle has caused very serious injury during the 

 last few years. The American elm and sugar maple, both 



