Abstract:
Life table parameters of the bird cherry-oat aphid,
(
Rhopalosiphum padi
L.) were
determined on different barley (
Hordeum vulgare
L.) varieties. Experiments were carried
out under laboratory condition of 26±1ºC, 65±5% RH
and photoperiod of 16:8 (L:D)
hours. Newborn first instar nymphs of the same age
were reared on the leaves of six
barley varieties using leaf cages. Nymphal developm
ent time, mortality, longevity and
adult fecundity were recorded daily. Nymphal surviv
orship varied from 71% to 88% on
the varieties tested. The results revealed signific
ant effect of experimental varieties on
demographic statistics of
R. padi
. The intrinsic rate of natural increase
r
m
, ranged between
0.318 and 0.366 female/female/day; the range of oth
er life table parameters was from 1.37
to 1.44 day
-1
for finite rate of increase
λ
, 43.83 to 60.65 female/female/generation for net
Reproductive rate
R
0
,
1.89 to 2.17 days for Doubling Time
DT
and 11.19 to 11.86 days for
mean generation Time
T
. In conclusion, analysis of biological parameters
indicated
Valfajr and Fajr30 as relatively less susceptible v
arieties to
R. padi
, while Reihan03, Kavir
and Zarjow were considered as relatively more susce
ptible and Nosrat was placed in the
same statistical group with other varieties.
Keywords:
Barley, Integrated pest management
,
Life table, Plant resistance.
