It seemed at first improbable that the Crambus could be the cause of 

 the mischief, as the species of this genus, so far as I was aware, were 

 known to feed only on Gramiuete and particularly on common grasses. 

 Mr, Felt has lately found that some of them, including this species, will 

 feed also on Rumex, though all apparently prefer grasses. On my visit 

 last autumn I was better able to examine the nature and extent of the 

 injuries caused by the larva and to obtain specimens nearly or quite 

 mature. The precise depredators had been readily found by Mr. Briggs 

 and the men in his employ at .work about the running portion of the 

 plants extending along the surface of sand in the stratum of fallen 

 leaves which always covers an old cranberry bog, and from which the 

 delicate clusters of new rootlets take their rise; square rods of the 

 meadow were scorched as by fire, in some places a half acre or more, and 

 everywhere, but especially along the borders of the portions of the fields 

 attacked, the larvje could be found in filmy silken galleries following 

 the prostrate stems or runners, into the surface of which they had 

 everywhere eaten their way, destroying the vital part of the plant and 

 often, especially next the base of the runners, deeply girdling the stems. 



Besides collecting a number of the largest larvae and taking them 

 home to rear, a large sod containing others was transported to Cam- 

 bridge and placed in a favorable position for their hibernation. By 

 cursory examination from time to time it was proved that the larvse 

 formed their coarse cocoons of mingled sand and silk just at the surface 

 of the ground late in the autumn (about November), remained in the 

 same stage within the cocoons until the latter part of INIay or early 

 June, when they changed to chrysalis, and after about a month reap- 

 peared as moths, when their identity with the supposed culprit flying 

 at large over the bogs in the first days of July was proved. The cages 

 were kept in a cellar until the moths appeared, all of which were males, 

 and came out July 6 and 7. 



This would appear to be the normal habit of life of this creature on 

 the Plymouth cranberry bogs, and the record of Mr. Felt shows the moths 

 flying at Ithaca, N. Y., in July only. But Prof. John B. Smith states 

 that he has taken the moths on cranberry bogs in Ocean County, N. J., 

 in May, and Mr. Briggs tells me that some vines which were green 

 immediately after the spring plowing died before the month of July, 

 apparently from the attacks of the same insect, as if caterpillars which 

 had passed the winter fed again in the spring before pupation : so it 

 may be that there is some considerable time variation in the maturity 

 of the larva. Mr. Felt also states that '' in the spring the larvie com- 

 plete their growth." 



The damage done at Plymouth was considerable; great patches of 

 scorched vines could be seen, sometimes a half acre in extent, in which 

 not only the year's crop had failed but the plants were almost entirely 

 destroyed; and considerable areas were seen where the damage of pre- 

 vious years had compelled replanting. There was this, however, to be 



