176 



]\1EMUIKS OF THE NATIONAL ACADEMY OF SCIENCES. 



the fourtb stage in the ratlier thicker body, sliglitlj' shorter imal le{;s, and thesmullcr (irst ahdinniiial 

 bhiek dorsal tubcrtdes, wliile tlie black spots on the eiuhtli ab<loininal segment aie more i)roiioiiiR'ed. 

 lircKpitiihition. — (1) The larva hatches with the yeiierie tdiaractcrs already established, viz, 

 with the long slender retractile anal Ic-^s, unprovided with hooks, and with the pair of hairless 

 doisal tubercles on the first abdominal segment. (2) The two dorsal tubercles on the eijihth 

 abdominal segment lose tiie hairs at the lirst molt and bejiin to assume tiie shape and enloration 

 seen at the last stage. {.'{) The clavate hairs disajipear with tlie second molt. (-1) In the third 

 stage the coloration and markings of the species begin to appear, the body changing from 

 peagreen to straw-yellow, the skin smooth and shining, and the lines and spots blackish, while 

 tlie reddish tint of the lirst abdominal segment, characteristic of the lirst stage, is di.seardcd. 



The earliest stages of Dasylophia are very different from those of Si/mi)icri.s1(i. the latter 

 apparently lacking the clavate hairs and tubercles of the former genus. 



It is i)robable, tliough further held work is needed to prove it, that by the third stage the 

 caterpillar is exjjosed to the same dangers and escapes them in the same way as the larva iu 

 its linal stage. Observations as to the position of the larva while feeding on the locust or wild 

 indigo leaf are needed iu order to show how the re(l<lish head, shining straw yellow body, and 

 blackish stripes and marjcings assimilate it to its habitat; also whether Ichneumons are rei)elled 

 by the movements of the anal legs, and whether such motions of the end of the body are sufficient 

 to drive away ichneumons and Taehina' from its otherwise unprotected, smooth body. 



These remarks will also apply, tlnnigh less strongly, to the caterpillar of iSymiiicrisId ulbij'niiis, 

 T\iiicli has similar shape and coloration, though its anal legs are not retractile nor so long and 



slender, and hence not so well calculated to frighten away unwel- 

 come insects. Experiments should also be made to asct'itain 

 whether the two larviB in question are distasteful or not to birds. 

 It ma}' be here observed that altlumgh many insects, according 

 to the I'ecent views of Exner and Plateau, may not distinctly per- 

 ceive the outlines of bodies, yet all insects doubtless .see objects 

 in motion. ITence any ichneumon or Taehina, or the carnivorous 

 beetles or bugs, may be frightened away by the sight of a mov- 

 ing or nodding tubercle like those on many Notodontians, and 

 still more by the movements of the lilaiiieiital ore\en the slightly 

 elongated legs of other forms, or b.y the upturned abdomens of 

 Da tana caterpillars. 



Cocoon. — "It formed a cocoon of leaves and siiic of thin 

 loose texture" (Harris Corresp., p. 30G). '• Fupa enveloped in a 

 thin, but a somewhat tough, cocoon comjiosed of silk and bits 

 of earth, etc., constructed at the surface of the ground." (Dyar.) The cocoon is loose, rather irreg- 

 ular, with sand, etc:, adhering to the outside, forming a thin network of coarse silk, Just the sort of 

 structure to which the (a'cmaster hooks would adhere to hold the iuii)a in jilace. -'■'> by 1- mm. 



Pitpa. — "It is -.i mm. long, ii mm. in diameter, shining dark chestnut-brown: eremaster 

 short and blunt, terminating iu several booklets." (Dyar.) 



One S . Body rather long, moderately thick, ui)i)cr surfa.-"e of thorax finely corrugated. 

 Abdominal segments only ininctuied near the sutures and liiiely granulated on hinder edge of 

 segments .5 to 7. Two S sexual openings or scars on segment 9 instead of one. End of body 

 tapering to a point. Cremaster conical, cleft at the end; surface longitudinally corrugated, each 

 fork or spine truncate, and bearing three long seta-, which are curved at the end as in tig. G7. 

 Length, 20 mm. (U. S. Nat. Mus.). 



Habits. — Harris found the larva on Podalijrhi tlnctorid August 3. " Its position when at rest 

 is like the gregarious caterpillars ( Pyfimui) of the ajiple tree, the head and tail being elevated." He 

 found anothfM' caterpillar on Lcspvdeza ctipifata. "August 9 to 10 it formed a cocoon of leaves and 

 silk of thin loose texture; August 13, became pupa," the moth appearing the following June. 



Dyar, writing in New York, states: "The dni-ation of each stage was about four days, with 

 the ex(;eption of the last, which was six days. The eggs hatched August 17 and the larva ceased 

 feeding September <>. They became pupa in a few days after constructing their cocoon, and 

 passed the winter in this stage. There are two broods of this insect in a season, those here 

 •described being of the second brood." 



Fin. C9.— Pnpii of Dasylophia aiipuina: 

 an. I., ve.sUges of uu.ll h'gs. 



