176 



MEMOIKiS OF THE NATIOXAL ACADEMY OF SCIENCES. 



the fourtb stage in tlie ratlier thicker body, sligiitly sliorter anal legs, and the smaller fii'.st abdominal 

 black dorsal tubercles, while the black spots on the eighth abdominal segment are more pronounced. 

 RecapitHhttion. — (1) The larva hatches with the generic characters already established, viz, 

 with the long slender retractile anal legs, unprovided with hooks, and with the pair of hairless 

 dorsal tubercles on the tirst abdominal segment. (1.*) The two dorsal tulicrcles on the eighth 

 abdominal segment lose the hairs at the first molt and begin to assume tlie shape and coloration 

 seen at the last stage, (.'i) Tlie clavate hairs disappear with the second molt. (4) In the third 

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

 pea-green to straw-yellow, the skin smooth and sliiniug, and the lines and spots blackish, while 

 the reddish tint of the first abdominal segment, characteristic of the first stage, is discarded. 



The earliest stages of Dasylophia are very different from those of St/nimerista, the latter 

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



It is probable, though further field work is needed to prove it, that by the third stage the 

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

 its final 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 reddish head, shining straw-yellow body, and 

 blackish stripes and markings assimilate it to its habitat; also whether ichneumons are repelled 

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

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



These remarks will also apply, though less strongly, to the caterpillar of Symmerista albifrons, 

 which has similar shape and coloration, tliough 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 ascertain 

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

 It may be here observed that although many insects, according 

 to the recent views of Exuer and Plateau, may not distinctly i)er- 

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

 in motion. Hence any ichneumon or Tachiua, or the carnivorous 

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

 ing or nodding tubercle like those on many Notodontiaus, and 

 still more by the movements of the filauiental or even the slightly 

 elongated legs of other forms, or by the upturned abdomens of 

 Datana caterpillars. 



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

 loose texture'' (Harris Corresp., p. 300); '• Pujia enveloped in a 

 thin, but a somewhat tough, cocoon composed 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 cremaster hooks would adhere to ht)ld the pnpa in ]ilace, L'3 by 12 mm. 



Pupa. — "It is 23 mm. long, 6 mm. in diameter, shining dark chestnut-brown: cremaster 

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



One S . Body rather long, moderately thick, upper surfa.^e of thorax finely corrugated. 

 Abdominal segments only jiunctured near the sutures and finely 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 iu fig. 67. 

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



Habits. — Harris found the larva on Podah/ria tiiu-toria August 3. " Its iiosition when at rest 

 is like the gregarious caterpillars {Pyt/a'ra) of the apple tree, the head and tail being elevated." He 

 found another caterpillar on LespnJcza capitaia. "August 9 to 10 it formed a cocoon of leaves and 

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



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

 the exception of the last, which was six days. The eggs hatched August 17 and the larva ceased 

 feeding September 0. 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." 



Fig. 69.— Papa of Dasyloi^hia aiifjuina: 

 ■ an. L, vestiges of jiual legs. 



