BIONOMICS OF THE CHINCH BUG. 



Table 2. — Length of incubation period of eggs of Blissus leucopterus, Columbia, 



S. C, 1 919-20. 



Eggs deposited. 



Eggs hatched. 





Eggs deposited. 



Eggs hatched. 











Length 

 of egg 











Length 



















of egg 



Date. 



Num- 

 ber. 



Date. 



Num- 

 ber. 



stage. 



Date. 



Num- 

 ber. 



Date. 



Num- 

 ber. 



stage. 











Days. 











Days. 



May 4 



3 



May 29 



3 



25 



June 1 





June 17 



8 



16 



May 6 



6 



May 31 



1 



25 







June 18 



1 



17 







June 1 



3 



26 



June 2.. 



33 



June 17 



14 



15 







June 2 



2 



27 







June 18 



12 



16 



May 8 



103 



May 31 



12 



23 







June 19 



2 



17 







June 1 



43 



24 







June 20 



2 



18 







June 2 



40 



25 



June 3 



32 



June 16 



1 



13 







June 3 



2 



26 







June 17 



3 



14 







June 4 



1 



27 







June 18 



8 



15 









2 



28 







June 19 



16 



16 







June 6 



2 



29 







June 20 



1 



17 

















June 21 



June 22 



1 

 2 



18 





June 8 



1 



31 



19' 



May 9 



9 



June 2 



6 



24 



June! 



17 



June 18 



4 



14 









3 



25 







June 19 



7 



15 



May 10 



37 



June 2 



June 3 



June 4 



19 

 14 

 2 



23 



24 

 25 







June 20 



5 



16 





June 22 



1 



18 





21 



June 6 







June 5 



12 



June 19 



June 20 



1 



14 





June 6 



June 2 



2 

 3 



26 



22 





May 11 



June 21 



10 



16 







June 3 



June 4 



11 



5 



23 



24 







June 22 









June 23 



1 



18 







June 5 







June 10 



6 



June 22 



1 



4 



12 





June 6 



2 



26 



13 



May 12 



48 



June 3 



4 



22 







June 24 



1 



14 







June 4 



28 



23 



June 11 



10 



June23 



2 



12 







June 5 



11 



24 







June 24 



5 



13 







June 6 



5 



25 







June 25 



3 



14 



May 13 



39 



June 3 



1 



21 



June 12 



9 



June24 



3 



12 







June 4 



8 



22 







June 28 



6 



16 







June 5 



12 



23 



June 15 



11 



June 28 



2 



13 







June 6 



18 



24 







June 29 



7 



14 



May 17 



66 



June 6 



14 



20 







Julyl 



2 



16 







June 7 



39 



21 



June 19 



3 



July 3 



3 



14 





j June 8 



13 



22 



June 23 



7 



July 6 



7 



13 



May 18 



2 i June 9 



1 



22 



June 26 



1 



July 9 



1 



13 







June 10 



1 



23 



June 27 



46 



July 10 



44 



13 



May 19 



12 



June7 



12 



19 







July 12 



2 



15 



May21. 



3 



June 12 



3 



22 



June 28 



5 



July 11 



2 



13 



May 22 



2 June 12 



2 



21 







July 12 



3 



14 



May 25 



58 June 14 



18 



20 



Julyl 



1 



July 12 



1 



11 







June 15 



39 



21 



July7 



14 



July 16 



1 



9 







June 16 



1 



22 







July 17 



2 



10 



May26 



22 



June 14 



6 



19 







July 18 



11 



11 







June 15 



16 



20 



July 8 



6 



July 20 



6 



12 



May 27 



27 



June 14 



1 



18 



July 11 



12 



July 23 



12 



12 







June 15 



23 



19 



July 12 



14 



July 25 



13 



13 







June 16 



3 



20 







July 26 



1 



14 



May 2S 



18 





14 



18 



July 24 



2 



Aug. 4 



2 



11 







June 16 



4 



19 



July 26 



5 



Aug. 8 



5 



13 



May 29 



23 



June 15 



1 



17 



July 27 



2 



Aug. 5 



2 



9 







June 16 



22 



18 



Aug. 21 



6 



Sept.5 



6 



15 





11 



June 16 



2 



15 













Total number of eggs, 664. Weighted average for the egg period, 21.96 + days. 

 FERTILITY OF THE EGGS. 



Not all of the eggs laid by the chinch bug are fertile. Fertility 

 may depend upon the number of times the female has mated or upon 

 whether or not the female has recently mated. The fact that the 

 female lays infertile eggs at times may explain the necessity for 

 frequent copulation, for should she mate only once or the mating 

 interval be too great, more of the eggs might be infertile. This, 

 however, is somewhat conjectural and further observations on this 

 point are necessary. In one instance 40 eggs out of a total of 503, 

 or about 8 per cent, were infertile. In another case 5 eggs out of 



