FISHERIES, GAME AND FORESTS. 357 



day or two. Over half the total number of eggs may be laid within about 12 days 

 at the height of the season, which in 1898 was from June 12 to 23. One female has 

 been known to deposit 623 eggs and it is possible that under more favorable condi- 

 tions an even larger number might be produced. 



The young grubs emerge from the eggs early in June, as a rule, or in about five 

 or six days after the eggs have been deposited, later in the season. They soon 

 begin to feed on the under surface of the leaves, producing the familiar skeletoniz- 

 ing shown in figure 2 and plate 1, figures 7 and 8, which is caused by their eating 

 the softer under part, leaving the upper epidermis and the veins. The results of 

 their feeding is so marked that it is easy to detect the presence of the grubs by the 

 semitransparent patches in the foliage, which soon dry and turn brown. 



The grubs complete their growth in from 15 to 20 days in summer (in cooler 

 weather the time is extended), become restless, forsake the leaves and descend the 

 limbs and trunk to a great extent, seeking a slight shelter under which to pupate. 

 Seven days are spent in this state in warm July weather, while in September it is 

 extended to 12 days and in October to 24. The descent of the grubs of the first 

 brood usually occurs in Albany the last of June or early in July. Some were 

 observed descending June 19 in 1896 and beetles of the second brood were to be 

 found on June 30. The oviposition of the second brood of beetles may begin by the 

 middle of July and from then till late in autumn it is possible to find all stages of 

 the insect in some part of Albany. The beetles of the second brood are naturally 

 attracted to fresh growths of foliage and consequently more eggs are deposited on 

 such trees, which are most frequently those defoliated earlier in the season. Thus 

 a tree is very apt to lose two sets of leaves in a season and may possibly have its 

 third set badly marred by this pest. The second brood of grubs may complete their 

 growth about the middle of August, transforming to beetles the latter part of the 

 month, and if there be an abundant supply of fresh leaves, a third generation may 

 be produced in considerable numbers. This last brood rarely develops on the sec- 

 ond or third set of leaves, but is more frequently found on nearby trees which had 

 not suffered much, earlier in the season. It may be considered the rule in Albany 

 that a considerable second brood will appear with a possible third generation in 

 smaller numbers. This beetle attacks European elms by preference, though fre- 

 quently it is very destructive to American elms. 



Natural checks. Many have thought that in the course of a few years some 

 natural agent might reduce this grievous pest to comparatively harmless numbers. 

 This can hardly be expected for some time, at least, because the beetle is still very 

 injurious at Washington, D. C, where it has been for many years, and the same is 



