147 
u curly" or " birds-eye" poplar, was the resul* of the injury in the bark 
by woodpeckers. 
The potato-scab gnat. — During Xovember I obtained a fresh supply of 
material for the continuation of an investigation, commenced in Septem- 
ber, 1891, to determine the relation of certain dipterous larvae to the 
so-called potato scab and to certain other injuries to the potato tuber. 
This investigation has resulted in the determination of some interest- 
ing facts, among which I may mention in this connection the following: 
First. That two species of so-called fungous gnats Mycetophylidie, one a Sciara, 
the other an Epidapus, will attack and feed upon healthy vegetable tissue : a fact 
regarding the habits of the Mycetophilid which, I believe, has never before been 
demonstrated. It was also determined that the latter species, which I have 
described under the name of Epidapus scabies, will develop from eggs to imago in the 
healthy or sound substance of potato tubers. 
Second. That the larva of Epidapus scabies will cause injuries in the outer portion 
of potato tubers which would be recognized as so-called potato scab, and that under 
favorable conditions they will feed upon the tubers until all but the epidermis is con- 
sume d. 
Third. That the presence of stable manure and decomposing vegetable matter in 
the soil, together with moisture, are the most favorable conditions for the presence 
of these insects, and that under such conditions serious loss is caused by them to 
potato growers. 
It may be of interest to note that the male of Epidapus scabies is 
the first male of the genus ever recorded, although the genus has been 
known in Europe for over fifty years. Some of the results of the 
investigation were presented to the newly formed State Horticultural 
Society on April G, and in a paper read before the Washington Ento- 
mological Society on May 3, 1894. In the latter a full description, 
with illustrations of all stages of the species, was presented, and will 
be published in the Proceedings. The former will be published in the 
Proceedings of the State Horticultural Society. 
The following observations not noted in the above papers may be 
mentioned here: On February 3, a Proctotrypid, determined by Mr. 
Aslimead as Geraphron basalis Ashm., was observed to be quite com- 
mon in company with the Epidapus in the mushroom beds and on the 
floor in the greenhouse. It was also reared from manure infested by 
the scab gnat. It is. therefore, probably a parasite of this species. 
Several species of Staphylinidae were also common in the beds 
infested by the Epidapus, and as they increased in numbers the gnats 
decreased, and finally became so rare that it was scarcely possible to 
find an example. Philonthm longicornis Steph., P. nigritulus Grav., 
XanthoJinus eephalus Say., and Homalota lividipennis Mann., all deter- 
mined for me by Mr. Schwarz, were among the species met with in the 
manure. X. eephalus and H. lividipennis being especially common. 
A Cerambyeid in walnut icood. — January 18. an undetermined Oer- 
ambycid larva was found inhabiting the sound heart wood of living 
black walnut. This, together with large species of black ants which 
enlarged the mines of the wood-boring larva, cause serious damage in 
this valuable wood. 
5216— No. 2 7 
