226 THE CANADIAN ENTOMOLOGIST. 



NEW HISTORIES IN HYDRCECIA. 



BY HENRY BIRD, RYE, N. Y. 



The summer of 1899 was a remarkable one at Rye in the abundance 

 of Hydroecia larviie, as four species, never before noted in their larval 

 state, and which do not seem to have their early histories described, were 

 observed. Old acquaintances were to be found on every side, and some 

 hitherto very uncommon ones were so abundant that a word in the matter 

 of cause and effect may not be amiss. The seasonal conditions are, of 

 course, contributive to such good results ; still, the numbers in evidence 

 every year suggest our looking a little further. Briefly, the environments 

 are most propitious for the development of these borers, as that most im- 

 portant question, food supply, can be relied upon being adequate to all 

 demands. The proximity to salt water insures a copious dew-fall, so that 

 vegetation in the months of July and August does not suffer from the 

 usual drought of this season in any such manner as it does farther inland. 

 Here in late midsummer the larger Compositte and other thick-stemmed 

 plants are in full splendour, while fifty miles back from the coast all may 

 be parched and leafless. So with a vigorous plant-growth assured, our 

 friends are able to exercise their fondness in clinging to familiar haunts, 

 and year after year we can be sure of finding a colony in the same par- 

 ticular location. While noted for their preference to certain places, there 

 are a number of causes more or less evident which frequently make them 

 leave the plant of theii first selection, and it is under such circumstances 

 that another stem close at hand is so important to their welfare. Water 

 draining into their galleries may have something to do with this move ; 

 still, that cannot apply in all cases, and this trick of seeking pastures new 

 is very general to all species. With the ordinary leaf-feeding cater- 

 pillar this might be accredited to mere instinctive vagaries of one sort or 

 another, but for a larva to forsake a commodious burrow that has taken 

 the greater part of its existence to make, and which still seems to offer 

 all the requisites for its well-being, is harder to explain. However, the fact 

 remains, and no doubt plays an important part in the mortality of a 

 brood, so an abundance of food plant close at hand is a great factor in 

 the ultimate results, as without it a certain percentage would surely 

 starve. Evidences of the effect of this prodigality not only arise from the 

 numerous forsaken galleries we encounter, but the number of dwarfed and 

 evidently starved-out adults found when they make their flight is very 



