r^SYCHE 



THE LIFE-HISTORY OF SEIRARCTIA ECHO. 



BY ALPHEUS SPRING PACKARD, PROVIDENCE, R. I. 



In Entomologica Americona for Au- 

 gust, 1SS9 (vol. 5, p. 153-155), Mrs. An- 

 nie Trumbull Slosson gives an interesting 

 account of the occurrence of Seirarctia 

 echo Abb. and Sm. in Florida, notes its 

 habits and adds a description of the 

 fullv grown caterpillar, prepared by 

 Air. H. Edwards. She kindly sent me 

 the eggs from Ormond, Fla., on the eve 

 of my departure to Europe for the sum- 

 mer. These Mr. Joseph Bridgham 

 kindly raised for me, and made excel- 

 lent enlarged colored sketches of the 

 larva in its ditl'erent stages. As these 

 are evidently faithful studies, and as 

 Mr. Bridgham has drawn under my 

 direction the early stages of other arc- 

 tians, I think it will be safe to describe 

 them from his drawings, although un- 

 fortunately none of the caterpillars were 

 preserved in alcohol. The eggs are 

 laid in Florida on the dwarf palmetto 

 {Sabal pahnetto) ; my specimens were 

 fed on lettuce. 



Stage I. — Length 2^-3 mm.. Head 

 nearly as wide as the thickest part of the 

 body, being but slightly narrower than 

 the prothoracic segment ; in tint, dark 

 brown, rather darker than the body ; 

 rounded. Body of the same thickness 

 from the 1st thoracic to the Sth abdom- 



inal segment. A transversely sublunate 

 dorsal plate or rudimentary "conical 

 shield" on the prothoracic segment bear- 

 ing on the front edge a slightly curved 

 row of six moderately large piliferous 

 warts ; behind which is a tranverse row 

 of smaller ones ; the spinulate hairs 

 arising from the larger warts are very 

 long and project over the head. Behind 

 this plate on each side is a single pilifer- 

 ous wart ; farther down in front are two 

 adjoining warts, and still farther down is 

 another group of two similar warts. 



The warts on the meso -and metatho- 

 racic segments are similar in shape, size 

 and position. On each side of each 

 segment is a group of three large warts, 

 two of them coalesced, the third one be- 

 low the others. On abdominal seg- 

 ments I — S there are two rows of small 

 dorsal warts, two to each segment, which 

 are 7iot present on the thoracic seg- 

 ments. The arrangement of the sub- 

 dorsal warts is the reverse of that of the 

 two hinder thoracic segments ; of the 

 two sets of warts on each segment, the 

 upper or dorsal is a single large one, 

 and the two coalesced ones below are 

 in the same position as the lower single 

 one of the 2d and 3d thoracic segments. 

 Lower down are three lateral rows of 



