112
N. WALOFF
No.
No. of
yo of
Mor- A m m u -
enterstage
stage
tality
bted
ing
which
which ofthat
morstese
88 yo of yo of
died
died
stage
trrlitiee
initial eggno.
egg no.
stege
1967
Eggs
Eggs and larval instar I
Larval instar I1
Larval instars 111 and I V
Total mortality on broom
IV larvae and pupae in soil
Adults in autumn 1967
Survivors of preceding adults
to spring 1968
Survivors of 1967 spring
adults to spring 1968
Total adults spring 1968
201 760
-
78 686
76 847
1401
166 934
37 482
2469
-
39.0
62.44
3.03
83.61
3342
-
-
39.0
38.09
0.69
18.68
1 *22
-
-
39.0
77.09
77.78
77-78
96-36
97.68
123 074
46 227
44 826
7344
-
4875
1882
6769
1968
Eggs
h a 1 instars I-IV
Total mortality on broom
IN larvae end pupae in soil
Adults in autumn 1968
Survivors of preceding adults
to spring 1969
Survivors of spring 1968
adults to spring 1969
Total adults spring 1969
125 039
78 086
46 499
68 086
114 685
6098
2614
37.18
86-68
37.18
54.45
37.18
91.63
91.63
96.71
97.80
4-08
2 *09
10 454
5356
48-76
48.81
2742
1268
4000
TABLE XI1
Annual deviations of mortality in P. olivacea from t h e necessary
for stability (Richards and Walcfj, 1961)
Year
1964
1965
1966
1967
1968
Survivors of previous autumn
yo Mortality necessary for etageneration
11 820
13616
12047
2839
4876
bility (baed on fecundity)
97.41
97.19
97.44
96.60
93.92
% “Actual” mortality
97.04
98-16
9945Q
97.19
97.80
Difference
+0*37
-0.97
-2.15
-0.69
-3.88