THE CANADIAN ENTOMOLOGIST. 17 



THE LIFE-HISTORV OF CROCIGRAPHA NORMA NI, CRT. 



BY ARTHUR GIBSON, CP:NTRAL EXPERIMENTAL FARM, OTTAWA. 



On the 6th May, 1901, a cluster of 30 eggs of Crocigraphn 

 Normafii, Grt., was found by the writer. Six of these had been 

 destroyed and the contents eaten, probably by some hemipterous insect. 

 The eggs were laid in rows close together, touching each other, on the 

 upper side of a leaf of Caulophyllum fhalictroides, Michx., and formed 

 almost a complete square, an average of six eggs being in each row. 

 They looked as if they had just been laid. Young maple, ash and birch 

 trees were growing near by. 



Egg. — .Almost semispheroidal ; 0.7 mm. wide, 0.6 mm. high, about 

 31 ribs rising from almost near the base, which is flattened and pitted, 

 making it appear rotighened. The whole egg has a shiny appearance, 

 particularly so towards and at the tip of each rib. The ribs are 

 acutely angled, and the whole surface, except the base, is distinctly 

 marked with wavy, transverse ribs. When found, the eggs were white. 

 On the 7th May they were all ringed near the apex with reddish brown, 

 and there was also a blotch of this colour near the apex. The eggs 

 hatched on the nth May. 



Stage I. — Length, at first, 3.25 mm. Head 0.4 mm. wide, pale 

 brown, slightly bilobed, with a shallow furrow down the front ; mouth- 

 parts reddish; hairs on face pale. Body cylindrical, pale yellow; after 

 feeding, the food contents give a greenish appearance ; skin smooth, 

 shiny. The cervical shield is concolorous with head, and bears two rows 

 of transverse tubercles, 4 large ones in front and 4 smaller ones behind. 

 Tubercles on body shiny black, large, single-haired; tubercles i and iii in a 

 line, ii and iv almost in a line, but iv nearer to iii than ii is to i. Spiracles 

 very minute, faintly black, and in a line with tubercle iv, and about the 

 same distance from tubercle iii as from iv ; setse short and black. A 

 faint dark green dorsal vessel is apparent. All the feet are concolorous, 

 slightly darkened at tips. The first two pairs of abdominal feel on 

 segments 7 and 8 are aborted, only being about half formed. 



The young larvae are " loopers," and spin a considerable quantity of 

 silk ; when disturbed on a leaf, they rise up on their prolegs and assume 

 a sphinx-like attitude. Apple, beech, willow, elm, basswood, wild goose- 

 berry, ash, plantain, birch and wild cherry were offered, and while they 

 fed on nearly every one of these plants, elm and beech were the favourite 

 food. 



