SOUTHERX GEEEN PLAXT-BUG. 



21 



Table A". — Minimum length of instars of Nezara viridula based on records for first 



individuah.^ 



Period spent 

 in first instar. 



June 18-22 



Aug. 14-17 



Aug. 18-22.... 

 Aug. 1&-22 



Do 



Aug. 20-23 



Aug. 23-27 



Aug. 2S-31 



Do 



Aug. 30 to Sept 3. 

 Aug. 31 to Sept. 3. 



Aug. 31 to Sept. 4. ' 



Sept. 7-10 



Sept. 9-13 ' 



Sept. 10-14 



Sept. 12-17 , 



Oct. 6-15 



Oct. 11-17 



Oct. 14-lS 



Period spent 



in second 



instar. 



June 22-26. 



Aug. 22-29. 

 Aug. 22-26. 

 Aug. 22-28. 



Aug. 23-29 . 



Aug. 27 

 Sept. 2. 



Aug. 31 

 Sept. 7. 



Sept. 3-8... 



do 



Sept. 4-8 



Sept. 10-19... 



Sept. 13-20... 



Sept. 14-20... 



Sept. 17-25... 



Oct. 17-29 



Oct. 18 to Nov. 

 10. 



Period spent 

 in third instar. 



June 26 to July 

 4. 



July 7-13 



July 7-12 



July 24-30 



Aug. 26 

 Sept. 1. 



Aug. 28 

 Sept. 4. 



Sept. 8-16. 



to 



.do. 



do 



Sept. 19-27. 

 Sept. 20-28. 



do 



Sept. 25 

 Oct. 5. 



Period spent 



in fourth 



instar. 



July 4-12. 



July 12-22 



July 13-22 



July 26 to Aug. 



3. 

 July 30 to Aug. 



5. 

 Sept. 1-7 



Sept. 4-11 



Sept. 16-22.... 



Sept. 16-23.... 

 Sept. 16-25.... 

 Sept. 27 to 



Oct. 6. 

 Sept. 28 to 



Oct. 8. 

 Sept. 28 to 



Oct. 9. 

 0ct..3-is 



Period spent 

 in flflh instar. 



July 22-31 9 



Aug. 3-10. 

 Aug. .5-12. 

 Sept. 7-20. 



Sept. 11-26. 



Sept. 23 



Oct. 6. 

 Sept. 24 



Oct. 17. 

 Sept. 25 



Oct. IS. 

 Oct. 6-29.. 

 Oct. &-2,K. 



13 

 15 



to I 13 

 to ; 23 



to 



23 



22 



Oct.S-29 ! 21 



Oct. 9-2S. 



' For temperatures to which nymphs were exposed see figure 13. 

 NUMBER OF GENER.\TIONS ANNUALLY. 



As has been stated, eggs have been taken m the field at Baton 

 Rouge as early as April 13, and as late as November 8, while nj-mphs 

 in the fifth mstar were observed December 23. Life-history studies 

 were conducted in an insectary where both the maximum and mini- 

 mum temperatures are shghtly higher than those given by the 

 Weather Bureau of the United States Department of Agriculture 

 for Baton Rouge (fig. 13). Under these conditions it would appear 

 that, while the egg and nymphal stages may be passed in about a 

 month, during the summer months, adults usually do not begin 

 egg-laymg mitH nearly four weeks after molting the last nymphal 

 skin. Field and insectary observations indicate that four genera- 

 tions develop annually in the field at Baton Rouge. 



NATURAL ENEMIES. 



In spite of the disagreeable odor of the species of the genus, the 

 Bureau of Biological Survey has recorded finding specimens of 

 Nezara m the stomachs of certain birds, but it appears to have been 

 always Jiilaris that was found. N. viridula is probably also eaten. 



Morrill (7) and Whitm^arsh (13) mention the fact that the eggs of 

 Jiilaris are parasitized by a species of Trissolcus, and it would thus 

 appear that the eggs of viridula would also be attacked by this para- 



