139 



iSixth. Divisiou of the outer wall into distinct segments and hatching 

 of the embryo. 



When ready to issue the young larvae eat a small hole through the 

 inclosing epidermis and emerge. At first they are slender 22-footed 

 slugs; bodies white, translucent, much wrinkled; granular; 2-2.3"™ 

 long; upper part of the head cream colored; claws of the pectoral legs 

 eyesjlabrum, mandibles, brown; remaining mouth parts, whitish brown; 

 ring around the eyes black. The young worms begin their ravages at 

 once, eating small holes through the leaves. After feeding six or seven 

 days they pass through the first molt, are about one-half larger, the 

 dorsal and lateral surfaces yellowish green, ventral surface pale. At 

 each of the three succeeding molts, all of which occur within the next 

 eight or ten days, the color is of a deeper green. The larvae when full 

 grown are between .55 and .65 inch long. Head and mouth parts, claws, 

 and first joints of the pectoral legs are of a more distinct brown; body 

 a beautiful deep green, much wrinkled, with one dorsal and two lateral 

 obscure blackish stripes. Anterior segments but slightly larger than 

 the posterior ones. 



By the 1st of May the worms begin maturing and entering the earth, 

 and by about the 1st of June all have entered the ground. Entering 

 the earth to the depth of an inch or so, a frail earthen cocoon is formed, 

 on the inside of which there is a thin silken lining. Larvae in cocoons 

 formed May 1 have shrunk to one-half of their original length, but up 

 to date (August 22) have not pupated. The shrunken larvae still retain 

 their green color, but the stripes are more distinct, due no doubt to the 

 fact that they have been crowded into about one-half their original 

 length. 



As yet no second brood has been obtained. However, if the larvae 

 should pupate and issue any time in August or forepart of September 

 there would yet be time enough for oviposition, hatching of eggs, and 

 maturing of larvae before frost would interfere. This que tion will soon 

 be determ'ned, and, indeed, will prove to be an interesting one, since 

 there has been much confusion and controversy as to the number of 

 broods of the old pest, H. maculatus. It seems barely possible that the 

 two species have infested the same beds and have been confused with 

 each other in some of the observations made. It is hoped that, with 

 our present knowledge of the species, a further study of them in their 

 respective localities will determine questionable points. In this local- 

 ity there is slight evidence that both species are present. The evidence 

 is very slight, however, in that no adults of H. maculatus were capt- 

 ured, and but one immature larva in one hundred alcoholic spec mens 

 bears the unmistakable markings on the head which characterize the 

 larvae of that species. (See Fig. 23 for comparison of the heads of the 

 larvae of M. ignota and H. maculatus.) 



Numerous specimens of the adults of ilf. ignota were examined, neuration 

 of the wings especially noted, and no variation found. Some slight varia- 

 9250— No. 5— --2 



