84 



DECIDUOUS FEUTT INSECTS AND INSECTICIDES. 



rior third of dorsum of abdominal segments 3-8 covered with very 

 short, decumbent bhick bristles, the row not extending quite as far 

 as the spiracles on either side. Cremaster Avanting, replaced by six 

 very short black bristles which are nearly obsolete in some specimens 

 and appear as black dots. Bristles arranged on the submedio-dorsal 

 asj^ect of the anal segment as tw'o median pairs and one lateral 

 bristle on the outside of the median pairs. Wing sheaths, and leg 

 sheaths of first pair of legs, subequal, antennal sheaths longer, all 

 extending to about fifth abdominal segment, those of third pair of 

 legs projecting slightly beyond. Length, 6-9 mm. 



Observations upon a number of pupae during the month of July, 

 1908, in Washington, D. C., show the minimum length of this stage 

 to be 9 days, the maximum 12 days, while the average length for the 

 period is 10.9 days. The average number of days spent in the cocoon 



is 14,8. The average mean 

 temperature for the month 

 of July, or the time the 

 pupa^ under observation 

 were in the cocoons, was 

 78° F. 



ADULT. 



(Fis. 17.) 



Fig. 17. — The grape-leaf 

 nmericana) : Male moth 

 left, of femah- at right ; 



Kkeletonizer i Hnrrixhui 



a, antenna of male at 



h, venation of front and 



Uniformly blue-black, 

 except a yellow collar 

 which extends nearly to 

 ventral side. Wings, legs, 

 and eyes similar in color 

 to rest of body. Antenna^ 

 pectinate, more so in male 

 than in female, and plu- 

 mose in male, length about 

 five-sixteenths of an inch 

 in male, four-sixteenths of an inch in female. Abdomen longer, more 

 slender in male than in female and curved upward. Abdomen with 

 a fan-shaped, somewhat bilobed caudal tuft. 



Length of moth, 8-11 mm.; length of wing, 11 mm. 



Expanse of wing, 22-24 mm. 



The following is the original description by Harris : 



TJlne-blnek, with a saffron cdlorod collar and a fan-shaiKMl, soniowliat bilolxMl, 

 black caudal tuft. Expands from 10 lines to 1 inch. 



hind wings, 

 inal.) 



lOnlarged ; a, much enlarged. (Orif. 



