152 



a species very common in mnsliroom houses, and that it was j^articu- 

 larly destructive to the bricks of sjiawn. The first brood of the insect 

 breeds in these bricks and in the compost in which the mushrooms are 

 grown, and the second and hiter broods take the mushrooms theme elves. 

 So serious were the attacks of this fly that only one crop, the fii'st, can 

 be successfully grown, the later crops being destroyed by the Sciani. 

 The insect breeds in any decaying vegetable material, and the species 

 had not been determined. 



In reply to a question by Mr.' Hopkins, Mr. Smith stated that both 

 sexes are winged in the case of his species. 



In reply to a question by Mr. Smith, Mr. Hopkins stated that he did 

 not mean to assert that all the scab was caused by the Mycetophilid, but 

 that it caused one kind of scab. Mr. Smith added that there were 

 plenty of scabby potatoes in some fields in New Jersey, but though, 

 after hearing of Mr. Hopkins's discovery, lie had examined a great 

 many, he had never found an insect associated with it. 



The interrelations of Cerambycidlarvje and the woodi)ecker, and the 

 nature of the injury produced by the bird in its attacks upon the larvae, 

 were discussed by Mr. Hopkins in answer to questions. Mr. Hopkins's 

 paper was accompanied by the exhibition of many specimens of wood, 

 showing the markings and work of the insects and birds described. 



Dr. Lintner, after expressing his very great interest in the paper, 

 said that the assertion that the Mycetophilidie never attack healthy 

 vegetation was somewhat erroneous, as, in the case of the mushrooms, 

 they certainly did, and hence the difficulty, or imi)ossibility, of grow- 

 ing this crop late in the season. He said also that the case of Aphidid 

 parasitism uientioned contradicted Mr. Smith's stand in the matter of 

 parasites, and he thought Mr. Smith might be more nearly right if he 

 limited his conclusions to field insects; for certainly, in the case of 

 indoor insects, parasites are frequently, as in the present instance, of 

 exceptional and undoubted value. He asked also if the larvie of the 

 clover-leaf weevil, when afiected by fungus, are not white in appear- 

 ance. 



Mr. Smith replied that the diseased larvje are first gray and become 

 black as they shrivel and dry up. 



With reference to the twenty- seven- year life-period for the chestnut 

 timber worm, Mr. Lintner expressed himself as regretting any possible 

 competitor with the seventeen-year Cicada for the place of the longest- 

 lived insect, because we have been so long in the habit of ascribing to 

 this interesting species the longest period of insect development. He 

 suggested that the Lymexylon case is very likely analogous to many 

 others on record, of mere arrested development, in which the larva, 

 removed from normal conditions, sometimes remains for years without 

 transforming to the adult, as in the case of wood-boring insects emerg- 

 ing from furniture. 



Mr. Hopkins suggested the deposit of eggs year after year in the 



