1144 
Journal of Agricultural Research 
Vol. XXXI, No. 12 
Duration of the Fifth Stage 
All of the preceding records of the insect, from the incubation of 
the egg to the fourth-stage nymph, have been based upon mass 
observations, all the individuals present in one cage being utilized 
Fig. 2 .—Dysdercus obscuratus. A, Fifth-stage nymph; B, adult. X 6 
to make one record. A single record is therefore based upon the 
development of possibly a considerable number of individuals. In 
the case of the fifth-stage nymph, however, the number of specimens 
which were carried successfully through their entire life history, from 
