3i8 AGRICULTURAL EXPERLMENT STATION. 



Description of the Larva. 



The larva, with details, is illustrated on plate 98. When full- 

 grown it measures 6-7 mm.,^.24-.28 of an inch in length, 

 exclusive of the anal siphon. When young, the wrigglers are 

 whitish in color with a tinge of yellow or brown, and the head 

 and thorax are very large in comparison with the abdomen. 

 Large larvse are translucent, pale yellow or brownish with the 

 regions of the body proportionate. The head is sub-quadrate, 

 broadest through the eyes, about one and one-half times as long 

 as broad. Prior to the last larval stage it is larger than the 

 thorax, and usually immaculate; in the last stage, however, it is 

 smaller than the thorax, more chitinized and with blotches on the 

 vertex which, though variously shaped and diffused, are always 

 bi-symmetrical. Near the anterior part of the head are four 

 tufts, each composed of four or five hairs, and a somewhat 

 larger tuft at the base of each antenna. The antenna is large 

 and long, thickest near the base, tapering slightly for two-thirds 

 its length, then becoming abruptly very narrow to the apex, leav- 

 ing an offset upon which is a large tuft of long hairs ex- 

 tending considerably beyond the tip. The apex with three long 

 bristles, a shorter one, and a small articulated joint. In color it 

 is white, black at the apical third and at the base, the surface 

 covered with fine hair-like spines. The eyes are large, black and 

 occupy the broadest part of the head. The rotary mouth brushes 

 (fig. 98, 2) are entirely composed of simple hairs. The mentum 

 (fig. 98, 4) is pentagonal in form, with fifteen to twenty-one 

 teeth, always with an equal number on each side of the apical 

 tooth. The mandible (fig. 98, 5) is triangular in shape with 

 blunt corners. The maxillary palpus (fig. 98, 6) has a rather 

 small tuft at the apex ; the surface is clothed with patches of hair 

 and the basal joint is very small. The thorax is wider than 

 long, the angles very acute in small and half-grown larvae. Be- 

 side the normal lateral hairs, four small tufts of two or three long 

 hairs each, extending forward over the head are on the anterior 

 margin, and several smaller tufts are between these and the first 

 lateral tuft. 



The abdominal segments from one to six are subquadrate in 

 form, deeply constricted at the joints, especially in the anterior 

 segments. There are two hairs to the lateral tuft in all except 

 the first and second segments, these with three or four hairs; 

 smaller tuft hairs of very fine hairs are also on the dorsal part 

 of the seo-ments near the lateral borders. The seventh segment 



