POPLAR CATERPILLARS. 465 



42. Catoeala amatrix Hubner. 



The caterpillar of this moth was foiiud by Dr. Kellicott under a large- 

 toothed aspen {Populus grandidentata)^ on which it had probably been 

 feeding, as Mr. Fischer, of Bufl'alo, the following summer bred this 

 moth from caterpillars found on the Lombardy poplar. Prof. G. H. 

 French has also bred it ou leaves of the cottouwood and Lombardy pop- 

 lar. In pupating they spun the leaves together, lining them with a 

 very thin cocoon of silk. He thus remarks ou the egg-laying habits 

 of tliis species : 



October 14, 1882, a female C. amatrix was brougbt to me, from which I obtained the 

 next day 261 eggs. These begau hatching May 3, 1883, and continued hatching to 

 June 21, making the egg-period from 200 to 249 days. Only the few that hatched 

 first were fed, and the greater part of these failed to reach maturity, owing mainly 

 to a form of bacterial disease that has prevailed in most of the species of caterpillars 

 which I have attempted to raise this year, and it has not been confined to the breed- 

 ing cages, but has been as destructive in the fields. Two imagines were raised, one 

 pupating June 21 and producing the imago July 25, the other pupating July 8 and 

 hatching August 3. This gives us a minimum period of 277 days from the egg to the 

 imago. I am of the ojiinion that all our species [of Catoeala] are single- brooded. 



Hulst gives the willow as also its food-plant, but bis authority is not 

 given. 



The following account of the transformations are copied from Pro- 

 fessor French (Papilio, iv, p. 8) : 



Egg. — Somewhat spheroidal in shape, in longitudinal diameter being .02 inch and 

 the transverse .035 inch. They are ridged longitudinally, 14 of these reaching the 

 punctured area of the apex, these alternating with shorter ones that do not reach so 

 far. The base ia scarcely more flattened than the apex. Color very pale dull olive. 

 Duration of this period from 200 to 249 days. 



Young larva. — Length .12 inch. Color brown, one dorsal and three lateral stripes 

 a little darker than the rest of the body, hairs and head concolorous, the number of 

 feet 12. Toward the close of this period the sides are more of a brownish yellow 

 with four reddish brown stripes, the lower or substigmatal not clearly discernible at 

 first, and on the venter dark brown spots in the center of joints 4 and 8. Duration 

 of this period six days. 



After first molt. — Length, .35 inch. Color of the dorsum brownish buff, the sides 

 dark purplish brown ; by transmitted light it may be seen divided into four more or 

 less distinct lines, the pale alternate lines narrow and faint. Head brown, not very 

 dark, with faint traces of liues. Scarcely a trace of the center of the dorsum being 

 lighter than the rest of the dorsum. Venter pale, joints four to eight, with each a 

 central black spot. First and second abdominal legs about one-fourth the size of the 

 others. Duration of this period four days. 



After second molt. — Length, .65 inch. More striped than before, a dorsal stripe 

 somewhat moniliform, the center purplish brown ou a yellow field or the outer part 

 of the stripe yellow. Subdorsal line yellow; between this and the dorsal stripe a 

 stripe the color of the center of the dorsal stripe. Joint 8 a little raised, and all but 

 the center blackish. Subdorsal region with two stripes, the upper like the second 

 dorsal, the lower almost black; the substigmatal line and the one separating the 

 two stripes gray. The head striped with a number of blackish longitudinal lines. 

 Thoracic feet yellow, the others yellow with a black base. The black is a purplish 

 black and not clear. Venter pale yellow, with the usual black spots. Duration of 

 this period three days. 



. 5 ENT 30 



