184
N. WALOFP
TABLE LIV
Total number of Anthocork q p . COW in 10 minltree from March to
October 1959 and March to September 1960 (Anderaon, 29GZu)
A. nemorum A. n c m a d b A . sorothamni
Broom
Apple
Sdix spp.
sycamore
Lime
Hawthorn
Elm
Oak
Beech
Ash
Birch*
Nettle**
966
1082
823
721
666
489
180
109
23
71
34
1340
782
320
687
780
443
1049
30
26
56
48
6
0
378
0
0
4
51
0
267
3
0
1
0
4
~
-~ ~
~~
~
* Sampled only 1959.
** Sampled only 1980. 100 aweep/week.
(a) A. n e w u m is an ubiquitous predator, a general feeder and is
bivoltine in southern England. The overwintering population is practically all female and hibernation is under bark, litter and in any protected niche. In March, the adults aggregate, mainly on Sulix and then
disperse to other plants as these become inhabited with suitable prey.
Oviposition is in April and the f i s t adults emerge at the end of June.
The females have an extended ovipoRition period and the second generation nymphs are present from July to October.
(b) A. nemuZis. Anderson’s studies indicated that this species breeds
primarily on psyllid-infested trees, although adults occur on a range of
plants. The species is bivoltine, but it stays on broom only in its first
generatim. In June, the adults leave this host plant and disperse to
aphid-infested treea, where a small second generation is produced. Most
adults enter hibernation in July and August and the broom plantation
is re-invaded annually in spring.
(c) A. surothamni. This species is less mobile and is to a great extent
reetricfed to broom. It is bivoltine end the adults overwinter in dehisced
pods that remain on broom and also under bark of other treea. The
period of spring development coincides with that of A. ne?laoraliS but
is more extended and the second-generation nymphs occur in July and
August. The size of the eecond generation is appamntly determined by
the proportion of the first generation females that reproduce inseead of
entering xeproductive diapauee. Anderson (1062b) carried out some intermting experiments which Ahowed that fecundity of A. eardhumni
N. WALOFP
TABLE LIV
Total number of Anthocork q p . COW in 10 minltree from March to
October 1959 and March to September 1960 (Anderaon, 29GZu)
A. nemorum A. n c m a d b A . sorothamni
Broom
Apple
Sdix spp.
sycamore
Lime
Hawthorn
Elm
Oak
Beech
Ash
Birch*
Nettle**
966
1082
823
721
666
489
180
109
23
71
34
1340
782
320
687
780
443
1049
30
26
56
48
6
0
378
0
0
4
51
0
267
3
0
1
0
4
~
-~ ~
~~
~
* Sampled only 1959.
** Sampled only 1980. 100 aweep/week.
(a) A. n e w u m is an ubiquitous predator, a general feeder and is
bivoltine in southern England. The overwintering population is practically all female and hibernation is under bark, litter and in any protected niche. In March, the adults aggregate, mainly on Sulix and then
disperse to other plants as these become inhabited with suitable prey.
Oviposition is in April and the f i s t adults emerge at the end of June.
The females have an extended ovipoRition period and the second generation nymphs are present from July to October.
(b) A. nemuZis. Anderson’s studies indicated that this species breeds
primarily on psyllid-infested trees, although adults occur on a range of
plants. The species is bivoltine, but it stays on broom only in its first
generatim. In June, the adults leave this host plant and disperse to
aphid-infested treea, where a small second generation is produced. Most
adults enter hibernation in July and August and the broom plantation
is re-invaded annually in spring.
(c) A. surothamni. This species is less mobile and is to a great extent
reetricfed to broom. It is bivoltine end the adults overwinter in dehisced
pods that remain on broom and also under bark of other treea. The
period of spring development coincides with that of A. ne?laoraliS but
is more extended and the second-generation nymphs occur in July and
August. The size of the eecond generation is appamntly determined by
the proportion of the first generation females that reproduce inseead of
entering xeproductive diapauee. Anderson (1062b) carried out some intermting experiments which Ahowed that fecundity of A. eardhumni