REPORT OF THE ENTOMOLOGIST. 115 



or ten days after the pupse were fully developed, the perfect insects 

 made their appearance in the form of minute two-winged dark- 

 colored ilies, which were at once recognized as the Mycetobia (Myceio- 

 phila) persiccc. (Fig. 4.) Several of this genus feed upon fungi, and one 

 species, very similar, is mentioned by Dr. Packard as living in the putres- 

 cent sap under the bark of elm trees. Our correspondents, however, 

 hav^e no occasion to apprehend any iujury from this insect, as it only ap- 

 pears to feed upon the exuded gum, &c., and has nothing to do with 

 the larva) of the peach-tree borers, which, even when very young, can 

 be readily distinguished by their heads, their more robust forms, and by 

 their six small feet on the first three segments of the body — while the 

 larvse of the Mycetobia is long and snake-like in form, has no feet what- 

 ever, and is perfectly innocuous to the peach-tree. 



A letter was received in the latter part of July from a correspondent, 

 Mr. C Moralle, of Leesburgh, Virginia, containing a number of very 

 small white worms, or larva?, having distinct black heads. These 

 worms appeared to be clinging to each other by means of a viscid sub- 

 stance on the surface of their bodies, and formed a small living mass. 

 In the accompanying letter Mr. Moralle stated that what attracted his 

 attention was " the peculiarity about them that they gathered in a long 

 string, resembling a snake, piling themselves up thickly in the middle 

 and tapering at each end, and when they moved the whole mass moved 

 as in one body." Unfortunately these worms were all dead when they 

 arrived, but Mr. Saunders, of this Depaitment, brought a mass of simi- 

 lar larvce a few days afterward, which had been given him by a gentle- 

 man also in Virginia. These specimens were placed in a glass jar, hav- 

 ing a small quantity of damp soil at the bottom, and retained their ball- 

 shaped form for some time, and then commenced to creep round the 

 sides of the jar on the earth in a string, three or four abreast, and con- 

 tinued traveling for a couple of hours ; they then dispersed and buried 

 themselves a short distance under the surface of the earth, and changed 

 into pupae, appearing six or eight days afterward as perfect liies. These 

 Fig. 5. were about one-tenth of an inch in length, (expanse 



0.13,) of a dusky-black color, with dark brown legs 

 and dusky- wings. Upon examination they proved to 

 be a species of Sciara, (Fig. 5,) the larvaj or worms 

 of which usually feed upon decaying vegetable sub- 

 stances, and are frequently found in fungi. The 

 species above mentioned as occurring in Virginia is 

 very similar in habits to a European species, Sciara 

 thonuc, which is usually called the snake or army 

 V worm in Germany, from its habit of sometimes assem- 



bling in innumerable numbers, creeping among and over each other, 

 and hanging together by means of a viscid moisture, and forming a mass 

 like a snake or rope, sometimes several feet in length, and two or three 

 inches in breath. The fly of the European species, Sciara thomce, is d,e- 

 scribed as having yellow stripes or points on the abdomen, whereas 

 our American species (at least when dried) does not show any vestige 

 of yellow whatsoever on the abdomen, but is of a uniform dark-brown 

 color, although the worm or larva has the same habits of forming snake- 

 like processions. It is somewhat singular that these worms appeared 

 almost simultaneously in two places in Virginia, while no mention is 

 made of their appearing elsewhere. 



These insects {Sciara) generally do no damage to cultivated vegeta- 

 tion, although one species, Sciara {Molohrus) mali, is mentioned by Dr. 

 Fitch as being found in the interior of ai)ples, especially when pierced 



