8 



over the leaves, until often nothing remains but the stronger ribs. 

 They are always concealed on the lower side, and are not readily 

 noticed, even by an experienced eye, on account of their color, which 

 harmonizes surprisingly with that of the leaves. Another character- 

 istic of this species is, that, instead of descending to the ground to form 

 their cocoons below the surface, as is the case with 31. roscc, the larvie 

 always form their rather delicate and more or less transparent cocoons 

 in autumn in any suitable situation above ground, among fallen leaves 

 and other rubbish, while during the warmer months they spin up on 

 the lower side of the leaves or on the stems and branches of the plant 

 upon which they have been feeding. 



The first or spring brood of flies appears at Washington from the end 

 of April until about the 20th of May, or even later. In the selection 

 of suitable X)laces for the insertion of her eggs the female again differs 

 markedly from M. rosce, for while this species o\dposits under the cuti- 

 cle of the leaf, as is common with many other species, our Cladius 

 selects the upper side of the petiole of the leaves and inserts from one 

 to three eggs, and sometimes more, close behind each other in an oblique 

 slit made by the o\ipositor. There are sometimes two or three such 

 groups of eggs in one petiole. The first flies fi'om hibernated cocoons 

 issue as soon as the leaves put forth, and commence at once to oviposit. 

 The eggs hatch in from a week to ten days, and the young larvte 

 begin feeding during the first week of May. Growth is rapid, and 

 cocoons have been found by the middle of May. The pupa state lasts 

 about fifteen days, so that the second brood of flies ajjpears during the 

 last days of May. At this time the latest larvre have nearly attained 

 their full growth. The second generation of worms begins work usually 

 the second week in June, and from this time on, until quite late in Fall, 

 larvie of different stages may be found almost continuously, indicating 

 that there are at least three and perhaps four annual generations, the 

 last of the worms being found even as late as the first week in Novem- 

 ber. Nevertheless, during July there is comparative cessation of work 

 between the second and third broods of worms, and fresh growth during 

 this period is scarcely affected. The larv?e of the last brood, after 

 having attained full growth, descend to the surface of the ground and 

 spin up beneath any suitable object to pass the winter. 



DESCRIPTIVE. 



Cladius 2}fctinico>-ni8 FoiiTCT. Imago. — Average expanse $ 10 mm, (? 9 mm. Color 

 black, polislied, sparsely and finely pilose. Ocelli red ; eyes black and very finely 

 facetted; behind each of the posterior ocelli there is a deep sinus, and a shalloTV 

 basin inclosing the anterior ocellus. Antenna! cavities of the head much exca- 

 vated, so as to leave in front of the insertion of the antenna a sharp median 

 carina. Antennte black ; those of the male rather hairy, and with a rather long 

 terminal branch on upper side of joints 3-5 and a very small, tooth-like jjrojection 

 at the end of the sixth. At the base of the lower side of the third there is a promi- 

 nent, forward-curved, blunt process, while the apex of the third and seventh forms 



