INSECT NOTES. 31 



necessary here to state that certain forms are exceedingly com- 

 mon and some are known to be injurious to corn, potatoes, 

 apples, mushrooms, and other forms of plant life. 



Of the lower forms the larva of Mycetobia lives on decaying 

 wood and has also been accused of attacking the sound roots 

 of apple and peach trees, though it is very doubtful if they are 

 able to cause serious injury here. Walsh, Riley, and Glover 

 all agree as to the inoffensive character of the members of this 

 genus. The Sciophilinae and Mycetophilinae are known to live 

 upon decaying wood and also upon mushrooms. In the tenth 

 report of the State Entomologist of New York, Lintner quotes 

 a prominent mushroom grower as saying that the crowning evil 

 of mushroom culture is the maggot of the fungus gnat. "By 

 cutting open the mushroom you may see numerous worm holes 

 in some of these, both in the caps and the stems, and no doubt 

 can discover some of the maggots. They are tiny fellows with 

 white body and black head, measuring about 1-5 of ar, inch in 

 length. . . ." It may be stated in this connection that fre- 

 quently associated with the maggots of the fungus gnats are 

 larvae of Phoridae, also serious pests. 



The Sciarinac, a subfamily of the fungus gnats and known 

 to the Germans as Trauermiicken (Mourning gnats), which 

 also have been accused of damaging fungi by Doctors Smith, 

 Felt, and others, are probably less frequently found in sound 

 plants than in such as are already badly decayed, differing in 

 this respect from those mentioned before. Professor Forbes, 

 State Entomologist of Illinois, reports that they are occasion- 

 ally injurious to seed corn. They are also known to feed upon 

 potatoes affected by scab or rot, and in some instances appear 

 to be the precursor of some form of scab. This form of scab 

 should not be confused with the common potato scab (Oospora 

 scabies). They are found in apples associated with the rail- 

 road worm (apple maggot) and in bulbs of tulips and peonies. 

 Whether they are actually injurious to the roots of potted plants 

 is not yet definitely known, though they are looked upon with 

 suspicion by florists generally. 



Mycetobia divcrgciis Walker. 



The larva of this species, living in decayed wood from an 

 apple tree, was sent to us by a correspondent from Gardiner, 



