158 ENTOMOLOGICAL SOCIETY 



This species has been reared from potatoes obtained from 

 different sections of our State (West Virginia) and .from seed 

 tubers received from Philadelphia. It has also occurred in the 

 new greenhouse at the station in great numbers during the past 

 winter, and was reared from ordinary potting soil, from stable 

 manure, and was found common in all stages in the mushroom 

 bed in the greenhouse. 



That the larvae will feed upon and develop from eggs to pupae 

 in the healthy substance of the potato tuber there can be no 

 doubt, since I have repeatedly demonstrated the fact by transferring 

 the eggs and young larvae to slight wounds in the skin of the 

 tubers ; also by placing healthy young tubers with infested ones 

 in the breeding jar. That the wounds inhabited by them are not 

 necessarily extended by the action of fungi or bacteria is evident 

 from the fact that a wound which is being rapidly extended by 

 the larvae will cease to enlarge and commence to heal, or form 

 cork cells, as soon as all of the larvae are removed. 



Figs. 19 and 20 (Experiment 65203) show result of 

 scarified tuber placed in breeding-jar with tuber infested with 

 larvae. Experiment commenced March 3, 1894. The initials 

 A. D. H. were made with the point of a needle, by just breaking 

 through the skin of a healthy tuber. On March loth large 

 number of larvae were feeding in the wounds. On March i5th 

 the larvae had entered deeply into the substance (Fig. 20) ; 

 photographs and drawings made and experiment ended. Speci 

 mens as illustrated preserved in alcohol. 



Dr. Williston, to whom I sent specimens of this species, refers 

 to it, in a letter dated March 20, 1894, as follows : 



" The form is of especial interest, as the male has been 

 heretofore unknown. But a single species of the genus is known 

 {Epidapus venaticus Haliclay), and that has been rarely seen. 

 I have gone over the subject very carefully, and have no doubt 

 whatever but that it is a true Epidapus. Schiner and Winnertz 

 both thought that the female was a wingless Sciara, but the male 

 offers sufficient characters to distinguish the genus in itself." 



The long wing of one form of the male would place the 

 species with the Sciara, but the difference in the mouth-parts 

 and genital organs, antennae, tibial spurs, and tarsus are 

 sufficiently distinct to separate it from Sciara. 



The only difference I find from Schiner's description of 

 Epidapus is in the palpi, which are referred to by him as having 

 four joints. In the large series of examples examined, I have in 

 every case utterly failed to find a jointed palpus, but, instead, the 

 inverted cone-shaped organ described and figured. However, I 

 am not ready to say that the joints are obsolete. 



The fact that a large percentage of the males have short wings, 



