Abstract:
Spodoptera exigua
(Hübner) was studied in laboratory (25±1ºC, 60±5%
RH, and 16:8 L:D
h) exploring the antibiotic effects of 10 canola cu
ltivars (Sarigol, SLM
046
, Hayula
420
, RGS
003
,
Opera, Okapi, Licord, Modena, Zarfam and Talaye) on
its demographic parameters. The
age-stage, two-sex and the traditional female age-s
pecific life tables were constructed by using
the demographic data. The larval period was longest
on Modena (17.53 days) and pupal
period was longest on Opera (8.96 days). The longes
t and shortest development time of
immature stages lasted 29.96 and 25.82 days on Tala
ye and Okapi, respectively. Male adult
longevity was longest on Okapi (14.93 days) and sho
rtest on Hayula
420
(9.14 days), and female
adult longevity was longest on Zarfam (18.04 days)
and shortest on Hayula
420
(8.07 days).
Based on the two-sex life table, the net reproducti
ve rate (
R
0
), intrinsic rate of increase (
r
),
and finite rate of increase (
λ
) were highest on Okapi (352.96 offspring per indiv
idual, 0.201
and 1.223 day
-1
, respectively)
.
The lowest value of
R
0
was recorded on Opera (152.73 offspring
per individual) and lowest value of
r
and
λ
on Talaye (0.142
and 1.153 day
-1
, respectively).
The mean generation time (
T
) took longest time on Modena (36.41 days) and shor
test on
Okapi (29.06 days). The results of this study showe
d that ‘Okapi’ was the most suitable
canola cultivar for reproduction and population gro
wth of
S. exigua
, which revealed higher
susceptibility of ‘Okapi’ to this pest.
Keywords:
Beet armyworm, Two-sex life table, Population growt
h.
