BIOLOGICAL STUDIES OF THE GREEN CLOVEE WORM 



11 



with the foliage and renders detection difficult. The injury resulting 

 from the work of this caterpillar is of a scattered character, giving 

 the field a ragged appearance. Figure 12 shows a soybean leaf eaten 

 in a characteristic manner. 

 This distribution of injury 

 may partly be accounted 

 for by the readiness with 

 which the larvae leap off a 

 plant even when slightly dis- 

 turbed. The larvae, most 

 noticeably the young ones, 

 have the habit when mo- 

 lested of sharply bending 

 their bodies somewhat like 

 a jackknife instead of coil- 

 ing them. 



QUANTITIES OF FOOD EATEN 



In order to ascertain the 

 quantity of foliage eaten by 

 a single caterpillar in the 

 course of its life, a series 

 of larvae were supplied with 

 measured quantities of cow- 

 pea and alfalfa leaf, and it 

 was found that the average 

 larva consumed foliage equivalent to about 19 average-sized leaflets 

 of alfalfa. Table 4 shows the average quantity eaten by each of five 

 larvae during the first five instars, and by each of four during the 

 sixth. 



Fig. 12. — Soybean leaf eaten in characteristic manner by the 

 green clover worm 



Table 4. — Quantity of foliage eaten by larvae of the green clover worm 



Square 



Instar millimeters 



First 3. 9 



Second 34 



Third 84' 



Fourth 117 



Fifth 624 



Sixth 1,660 



Total 2, 522. 9 



LARVAL DEVELOPMENT 



The larva molts five times in the course of its development, although 

 in exceptional instances individuals have been observed to undergo 

 six molts. Table 5 shows the length of the instars from records of 33 

 larvae reared during summer and fall seasons in Tennessee. The 

 rearings were conducted in an outdoor insectary under conditions and 

 temperatures approximating the natural environment. The average 

 length of the larval period came to 22.84 days. 



