276 



PRODUCTION OF RACES AND SrECIES IN LEPTINOTARSA. 



Lot B. This lot, consisting of a mixture of hybrids and decemlineata from 

 the first hybrid generation (the D -\- 2 Dr), gave in the fourth lineal genera- 

 tion after hibernating, of L. decemlineata, 92 male and 91 female; L. pallida, 

 19 male and 31 female. These were separated and known as lot B 2 (de- 



i 



ccmlincata hybrids) and lot B 1 (pallida) and reared in the fifth generation, 

 giving from lot B 1 of L. pallida 20 male and 24 female ; and from lot B 2 

 of B 2a, L. pallida, 41 male and 40 female ; B 2b, L. decemlineata, 92 male 

 and 91 female. 



