230 THE CANADIAN ENTOMOLOGIST. 



some time ago, and which will serve to identify them on the alfalfa plant 

 hereafter, besides giving an idea of the forms which occur on alfalfa in 

 this locality. They were all collected in Las Cruces. The figures in 

 parentheses refer to the alcoholic specimens of the species in the ento- 

 mological collection of the New Mexico Agricultural Experiment Station. 

 (a). — Small, brownish and bristly Larva. 



Stage 2. — Length, 2t0 2^ mm. Brownish or blackish. Five pairs of 

 prolegs on segments 7 to 10 and 13. Head distinct, chitinous, shining pol- 

 ished black ; dorsum of prothorax also chitinous, emarginate behind, black- 

 ish. Rest of larva brownish, each segment with twelve circular dot-like 

 raised blackish papilke in an irregular transverse row, each papilla bearing 

 a black hair. Rows on thoracic segments straighten Head and pro- 

 thorax also hairy. It is barely to be perceived that the whole integument 

 is covered with microscopically short, bristly pubescence. Ten specimens. 



Stage 3. — Length, 3 to 4 mm. Head black, variegated with brownish, 

 or wholly very light, even pale-yellowish. Proscutum black. Ground 

 colour of larva about same as in preceding stage ; tubercles a little more 

 conical in form, black. The spiracles must not be mistaken for tubercles, 

 the former being smaller and showing on most of the segments in all the 

 stages. Microscopic bristly pubescence of integument slightly more 

 evident. Seventeen specimens. 



Stage 4. — Length, 5 to 5^ mm. Head usually very light, with four 

 faintly mottled areas of brownish ; prothorax rather light, but oftener 

 of the brown colour of rest of body. Tubercles more strikingly conical. 

 The integument shows very plainly the short, stubby, whitish and brownish 

 bristles, usually in longitudinal whitish and brownish rows. Nine speci- 

 mens. 



Stage 5. — Length, 5^2 to 7 mm. Head large, very pale-yellowish, 

 only three of the mottled faint brownish areas, the one near oral margin 

 being more or less obsolete. Black tubercles or papillae very conical ; 

 hairs longer and stouter, the larva therefore appearing somewhat more 

 bristly. The stubby, bristly growth of integument is very apparent in its 

 narrow, longitudinal, alternating white and brown rows. Eight specimens. 



Stage 6. — Length, 7*^ to 9 mm. Head about same as preceding 

 stage. Prothorax darker. The white longitudinal rows of stubby bristles 

 showing most plainly in the median region, and on each side. Five 

 specimens. 



