158 THE CANADIAN ENTOMOLOGIST. 



A NEW SILK-SPINNING CHALCID. 



BY L. O. HOWARD, WASHINGTON. 



During the summer of 1879, while working with Professor Comstock 

 upon the natural enemies of the cotton worm, I came across the following 

 passage in his field notes of the previous year : — 



"August 27. — I found yesterday a cotton worm about five-eighths of an 

 inch in length, which, though yet alive, was being destroyed by three 

 green larvae which were upon it. I found the specimens about 10 a. m. 

 Last evening I observed that the cotton worm was neaily eaten. The 

 parasites had very short bodies, which, when they moved, were pointed at 

 one end. I had intended to describe the specimens, but I find that they 

 have spun cocoons about their bodies. 



"August 28. — I found crawling over the ground a small cotton worm, 

 infested by five parasites, evidently of the same species as those mentioned 

 in my note of August 27. 



"August 29. — The small green parasites which I found yesterday, des- 

 troyed the cotton worm, and, excepting two specimens which I put in 

 alcohol, began to spin cocoons during the night." 



Upon looking the specimens up, I found that two adults had issued. 

 Owing to a lack of time the insect was not worked up for the Cotton 

 Insect Report, and only recently have I had time to study it. 



Instances in which Chalcid larvae have been observed to spin perfect 

 cocoons are rare. One of the most marked instances upon record is the 

 case of the European Euplectrus albiventris, which was first shown to have 

 this habit by Nees at Esenbeck (Hym. Ochn. Aff. Monogr. II. h 136). 

 "Westwood also states (Intr. II 163) that, in drawings of Chalcididae by 

 Fonscolombe, the larva of this same species was represented as feeding 

 externally upon a large caterpillar, and that in his description he, too, 

 noted its cocoon spinning habit. 



Now it is quite interesting to find that our cotton worm parasite is also 

 a Euplectrus, some thirty years having elapsed before M. de Fonscolombe's 

 observations have been verified. As explanatory of the fact that M. de 

 Fonscolombe and Professor Comstock both observed these larvae feeding 

 externally upon their hosts, it may be urged that this external feeding was 

 simply temporary and preparatory to spinning the cocoon, the larvae hav- 

 ing only recently emerged ; yet, from M. de Fonscolombe's wording, "sic 



