BIOLOGICAL. STUDIES OF THE GREEN CLOVER WORM 



green clover worm. 



Enlarged 



THE EGG (FIG. 4) 



Width 0.510 milliineter, height 0.346 millimeter. Subglobose, flattened, cir- 

 cular at the equator, with polar axis about two-thirds length of diameter; 14 to 

 16 prominent, acute, longitudinal ridges running from base to apex, each alter- 

 nate one slightly longer; interspaces concave and crossed by fine, transverse, 

 regularly placed ridges; polar area sculptured by a few fine ridges; base flattened 

 and taking impression of surface to which 

 attached. Color when laid shiny pale green, 

 sometimes distinctly bluish-green; partly 

 developed eggs with pale orange spots and 

 streaks scattered over upper surface, and in 

 eggs still further advanced with orange spots 

 turned to distinct, sparsely distributed, reddish 

 brown spots. Shortly before hatching the Fig. 4.— Egg 

 egg turns a dark metallic purplish-gray color. 

 The empty shell is colorless, transparent, and iridescent. 



THE LARVA (FIG. 5) 



First instar. — Length 1.5 to 4 millimeters, head width 0.265 to 0.285 milli- 

 meter. The newly hatched larva is slender and much constricted between seg- 

 ments. Head considerably wider than body; shiny, transparent, with faint yel- 

 low tinge. Body trans- 

 lucent grayish-white, 

 with alimentary canal 

 slightly darker. As the 

 larva develops the body 

 becomes faintly yellow- 

 ish, usually tinged with 

 green from' chlorophyll in 

 the alimentary canal. 

 Throughout this instar 

 the first three abdominal 

 segments are consider- 

 ably larger than the 

 others; the next four are 

 about equal in size; the 

 eighth, of the same width, 

 is considerably longer ; 

 the ninth is shorter and 

 narrower than any except 

 the tenth and last, which 

 is still shorter. The 

 constrictions are deepest 

 between the first four 

 abdominal segments. 

 Prolegs on the third and 

 fourth segments rudi- 

 mentary, those on fifth, 

 sixth, and last functional. 

 Head oblique, somewhat 

 flattened, pale, shiny, 

 transparent , yellowish , 

 tinged with green, caudal 

 edge dark. Numerous 



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*-**•*•* 



Fig. 



-Photograph showing a comparison of the six larval instnrs 

 of the green clover worm. Enlarged 



short setse are scattered over the face, with one long one on either side of frons. 

 Setae for the most part dark and moderately long, borne on small chitinizations 

 -lightly darker than surrounding tissues. 



Second invlar— Length 3.5 to 7.5 millimeters, head width 0.353 to 0.459 milli- 

 meter. As compared with the first instar, the first three abdominal segments 

 are not so distinctly larger than the rest, the constrictions between the segments 

 are less deep, and the rudimentary prolegs of the third abdominal segment are 

 less apparent, while those on the fourth have become functional. Body tubercles 

 nearly circular, slightly elevated, and same color as surrounding tissue; seta- fine, 

 long, and pale. 



