DYNAMICS O F FIELD POPULATION O F P I N E LOOPER
285
Here we start from the fact that pupal density in December is determined in succession by the density of first instar larvae, the juvenile
mortality, the mortality of advanced larvae and, finally, prepupal mortality. To be informed about the effects of these components we studied
the correlation between pupal density and the relevant densities of the
earlier stages of larval development. The results are presented in Fig. 35
0.5
1
1.5
2
Q
B
LO6 L,
1. .
. LOG N
0
0.5
1
FIG. 35. Regression diagrams for key factor analysis. LI, L,, N, and P refer to the densities of first instar larvae, September larvae, nymphs and December pupae. The encircled points represent densities from 1950-54, which are lacking in diagram C, because
nymphal density was not measured. (See text.)
285
Here we start from the fact that pupal density in December is determined in succession by the density of first instar larvae, the juvenile
mortality, the mortality of advanced larvae and, finally, prepupal mortality. To be informed about the effects of these components we studied
the correlation between pupal density and the relevant densities of the
earlier stages of larval development. The results are presented in Fig. 35
0.5
1
1.5
2
Q
B
LO6 L,
1. .
. LOG N
0
0.5
1
FIG. 35. Regression diagrams for key factor analysis. LI, L,, N, and P refer to the densities of first instar larvae, September larvae, nymphs and December pupae. The encircled points represent densities from 1950-54, which are lacking in diagram C, because
nymphal density was not measured. (See text.)