534 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



the rest quite distinctly shac^eened; in xylina the basal punctuation is less pro- 

 nounced and the rest of the segment smooth. All coxaj black (in xylina the apical 

 half of lower edge of posterior coxae is reddisli); the first Joint of metatarsi per- 

 ceptibly stouter than the other joints (almost like the other joints in xylina). Cocoon 

 white and smgle (in xylina the cocoons are enclosed in wooly masses). 

 Described from two 2 specimens. 



The Limneria Parasite of the Web-worm, — In addition to the 

 two Hymenopterons parasites treated of, a third one has been very 

 numerous, and has done much good in reducing the numbers of cat- 

 erpillars. This, an Ichneumonid, and a much larger insect, does not 

 form an exposed cocoon like that of the other parasites described. 

 Yet a little attention will soon reveal large numbers of them. Upon 

 the trunks of various trees, but chiefly upon those of the Poplar 

 and Sugar Maple, small colonies of caterpillars, varying in number 

 from 4 to 13, could be observed, which did not show any signs of life. 

 When removed from the tree they appeared contracted, all of the 

 same size, and pale or almost white, A closer inspection would re- 

 veal the fact that the posterior portion of the caterpillar had shrunken 

 away to almost nothing, whilst the rest was somewhat inflated, and 

 covered with an unchanged, but bleached skin, retaining all the hairs 

 in their normal position. Opening one of these inflated skins, a long, 

 cylindrical, brown cocoon would be exposed ; this is the cocoon of the 

 Limneria luider consideration. As numbers of such inflated skins 

 would always occur together, it was clearly seen that the same parent 

 Limneria had oviposited in all of them. Most of tlie cocoons were 

 found in depressions of the rough bark, or other protected places. 

 Single ones were but rarely met with. The Hyphantria larvse in dy- 

 ing had very securely fastened all their legs into the crevices of the 

 bark, so that neither wind nor rain could easily dislodge them. Only 

 half -grown caterpillars had thus been killed. Many of these inflated 

 skins showed in the early j)art of October a large hole of exit in their 

 posterior and dorsal ends, from which the Ichneumons had escaped. 

 Trying to obtain winged specimens of this parasite, 140 of these co- 

 coons — and only such as were not perforated in any way — were col- 

 lected and put in a glass jar. Only a single female was produced 

 from all up to time of writing, whilst very large numbers of second- 

 ary parasites issued from October 11 to November 20, and doubtless 

 others will appear during the spring of 1887, because some of these 

 inflated skins show as yet no holes of exit. 



This parasite is, according to Mr. Cresson, unnamed in the Phila- 

 delphia collection,- and, after close study of all accessible descriptions, 

 we have decided that it should be placed, temjDorarily at least, with. 

 Provancher's Limneria pallipes. The specimens which we have 

 bred correspond with his variety, in which the four anterior femora 

 are pale red. The sj^ecies is not unlike L. lophjjri Riley, which we 

 described in our Ninth Missouri Entomological Report from a large 

 series of specimens bred from the larvse of Abbott's White Pine 

 Worm {Lophyrus abbottii), but is smaller and has certain colora- 

 tional differences. 



The Tachina Parasite of the Web-worm, — The parasites of H. 

 textor described so far belong to the order Hymenoptera, which fur- 

 nishes the greatest number of them; but the fly now to be treated is 

 fully as useful as any of the others. We have not named and de- 

 scribed this species, on account of the fact that the family to which 



