Abstract:
The aim of this study was to evaluate the effect of ten d
ifferent sugar beet genotypes on
nutritional indices of the beet army worm,
Spodoptera
exigua
(Hübner) (Lep.: Noctuidae)
at 25±1°C, 60±5%
RH
and a photoperiod of 16:8 (L: D) hour.
The sugar beets evaluated
in this study included two sugar beet cultivars (H
M 1339 RZ and SBSI006), five
populations (SB26, SB27, SB29, SB33, SB34), one hybrid (7112*SB36)*Sh
-
1
-
HSF
-
5 and
two lines (FC 301 and FC 220). Fourth instar larvae reared on (7112*SB36)*Sh
-
1
-
HSF
-
5
showed the highest Relative Growth Rate (RGR) of 0.31 mg mg
-
1
day
-
1
, Relative
Consumption Rate (RCR) of 4.79 mg mg
-
1
day
-
1
and Approximate Digestibility (AD) value
of 94.35% compared with the other host plants. The lowest value of
RCR
(0.81 mg mg
-
1
day
-
1
) was on SBSI006. The Efficiency of Conversion of Ingested foo
d (ECI) was varied
from 1.80% on FC 220 to 9.14% on SB34. The highest
AD
value of fifth instar (92.63%)
was
on (7112*SB36)*Sh
-
1
-
HSF
-
5 and the lowest value of this index was recorded on SB27
(83.71%). The highest
AD
value of whole larval instars was noted i
n (7112*SB36)*Sh
-
1
-
HSF
-
5 (93.73%). The lowest value of
RCR
(1.78 mg mg
-
1
day
-
1
) was found on SB27. The
heaviest pre
-
pupa (81.01 mg), pupa (72.55 mg) and wet adults (19.14 mg) of beet
armyworm were recorded on (7112*SB36)*Sh
-
1
-
HSF
-
5.
The results indicated t
hat
(7112*SB36)*Sh
-
1
-
HSF
-
5 was the most suitable host for
S. exigua
that should be
considered in cultivation or breeding programs.
Keywords:
Antibiosis, Beet armyworm, Food consumption, Insect weight.
