Abstract:
Plant quality in herbivores’ diet may affect the pe
rformance of both herbivore and its
parasitoids. In the present research, parasitism ca
pacity
of
Diadegma semiclausum
(Hellen) on
Plutella xylostella
(L.) reared on different genetically manipulated
Brassica
plants including the
canola’s progenitor (
Brassica rapa
L.), two cultivated canola cultivars (Cultivar-Oper
a and
Cultivar-RGS
003
), one hybrid (Hybrid-Hyula
401
), one gamma mutated (Mutant-RGS
003
), and
one transgenic (Transgenic-PF) genotype was determi
ned. All experiments were carried out in
a growth chamber at 25±1 ̊C, 65±5% RH, and a photope
riod of 16:8 (L: D) hour. The value of
the net parasitism rate (
C
0
) of
D. semiclausum
was 14.94, 20.12, 14.95, 12.20, 13.94, and 12.55
hosts on
B. rapa
, Cultivar-Opera, Cultivar-RGS
003
, Hybrid-Hyula
401
, Mutant-RGS
003
, and
Transgenic-PF, respectively. The transformation rat
e from host population to parasitoid
offspring (
Q
p
) on all genotypes was close to 1 (
C
0
≅
R
0
). Moreover, the value of the finite
parasitism rate
( )
was 0.271, 0.285, 0.277, 0.202, 0.205, and 0.202 ho
st parasitoid
-1
day
-1
on
the above-mentioned genotypes, respectively. The fi
nite parasitism rate considers the finite rate
of increase, the stable age-stage distribution, and
the age-stage specific parasitism rate;
therefore, this parameter could be used to assess t
he efficiency of a parasitoid. In conclusion,
D.
semiclausum
had higher parasitism capacity on canola’s progenit
or and the cultivated
genotypes which were more suitable for parasitoid’s
host based on secondary metabolites
concentration.
Keywords
: Diamondback moth, Finite parasitism rate, Manipul
ated canola, Plant chemistry, Two-
sex parasitism.
