116 THE CANADIAN ENTOMOLOGIST. 



So attention was directed to other places, that have now produced 

 the information desired. By far the most enticing was the New Brighton 

 locality of western Pennsylvania, where the light traps of Mr. F. A. 

 Merrick yearly secured a few of the moths. Conditions of these captures 

 were such as to prove that the larvae must be at work in the immediate 

 vicinity of the traps, yet dig and delve as we may, search and eliminate, 

 try and guess again, for three successive years at a proper date, we were 

 unable to get the faintest clue to the food-plant. As if to give us the 

 laugh, the traps each year kept taking an increasing number of the moths, 

 and jovial Mr. Merrick, newer at the business and less callous to failure, 

 concluded we were stirring them up at any rate. At the close of the third 

 season, when the larval history of rigida began to look like an interesting 

 problem, light dawned from an unexpected quarter, and it was learned 

 that the insect had been reared by Mr. F. E. Moeser, of Buffalo, N. Y. 

 A specimen was forwarded to make sure that the larva he had discovered 

 was really (irote's species, and in the following summer, 190S, as a 

 guest of Messrs. Moeser and Lucas, the writer was introduced to the limited 

 locality wherein the species had occurred the year before. 



The food-plant was pointed out, and the author was considerately 

 allowed to locate and uncover unaided his first specimen of rigida larva, 

 which was an easy matter. Of course it is in a root, as was long suspected, 

 and when Hdianthus decapetalus was shown to be the answer to the riddle, 

 it was recalled that these plants had been duly examined at New Brighton, 

 but the fates had not kindly directed us to infested examples. 



At the middle of July there is little intimation of a larval presence, the 

 plants seem to be doing nicely and are beginning to bloom, and it is only 

 by close inspection at the root that the telltale frass and a minute hole in 

 the stem at the ground level are to be discerned. Being a plant of the 

 open, there are usually grasses or small weeds about the roots, completely 

 hiding this evidence, while any wilting or other detective clues are wholly 

 wanting. So the more credit to its discoverer, since only one Papaipema 

 bent would ever be likely to find the species, and it is not strange that 

 thirty years have elapsed without this larva being recorded. 



That Helianthm decapetalus is a preferred or primitive food-plant, 

 there can be little doubt, from the evidence at Buffalo, and what is known 

 of the plant. This is a question to be determined, though the range of a 

 food-plant does not necessarily restrict the faunal zone of a moth. A good 

 example occurs with P. impecuniosa, Grt., which changes from Aster to 

 Helenium autumnalt west of the Alleghanies, and flies over a very wide 



