49 



inal segment. Stigmatal tubercles quite prominent. Dorsum of thorax and wing 

 sheaths coarsely shagreened. Dorsum of abdominal segments rather sparsely punc- 

 tulate, the posterior border of each segment being smooth and shining. The anal 

 segment at its end is furnished with several (a variable number) minute recurved 

 hook-like spines. From the apex of the head to the end of the fourth abdominal 

 segment the dorsum is elevated into a slight ridge, more marked upon th£ abdominal 

 segments than upon the thorax. 



The cocoon. — Pupation takes place in a somewhat loosely built but 

 not fragile cocoon, those in our rearing jars having been formed just 

 upon the surface of the earth. They were constructed of particles of 

 sand joined together with silken web and sometimes attached to leaves 

 or other vegetation. They are of elliptical form and somewhat 

 depressed, and measure on the outside about 16-18 mm in length and 

 6-8 mm in width. 



ON THE HABITS OF THE SPECIES. 



In the report of this Department for 1879 (loc. clt.) attention was 

 called to the abundance of the moth in the District of Columbia dur- 

 ing the winter of 1878-79, when it was seen flying on warm, sunshiny 

 days, while in the summer months larvae were found so commonly 

 upon clover u that in many places one could hardly make a swing of 

 the beating net through the grass without capturing one or more of 

 them." 



The larvae are quite active, and when disturbed either let them- 

 selves down to the ground by means of their webs or quickly throw 

 themselves from their food plant after the manner of many Pyralids. 

 The moth is a rapid flyer, and although normally keeping in conceal- 

 ment, is often found exposed on the walls of buildings and on windows 

 in conspicuous places. 



In Bulletin No. 3 of the United States Entomological Commission 

 the late Professor Riley had a short note on this species, in which he 

 stated that the larva fed also on locust (Robinia), and gives some notes 

 on the hibernation of the species. He says that this insect hibernates 

 in the imago state all over the country and that in Missouri the chrys- 

 alis may also be found under bark in winter, but the habit of hiber- 

 nating in the pupa state is doubtless exceptional. The late and early 

 appearance of the moth would alone indicate that hibernation takes 

 place in the mature condition. 



Mr. Coquillett traced the insect through its various stages at Wood- 

 stock, 111. The periods were as follows: From the deposition of the 

 eggs to hatching, four to six days; larval stage, twenty-five days, and 

 from the spinning of the cocoon to the issuance of the imago, twelve 

 to fourteen da}^s. Only two larval molts were observed, the time 

 from hatching to the first molt being seventeen days, from the first to 



4670— No. 30—01 4 



