50 N. Veena and D. Manjunath
progenies (114.75 ± 1.97) when compared with
other mating combinations. The progeny sex
ratio was significantly higher ( P < 0.01) in ran-
dom mating (2.57 ± 0.03) in comparison to other
combinations (Table 2 ).
A significantly higher rate of parasitism, prog-
eny production, and sex ratio resulted in B♀ ×
B♂ mating combination among other combina-
tions, i.e., S♀ × B♂ and S♀ × S♂. Of the remain-
ing mating combinations, though the rate of para-
sitism remained at par, there was considerable
fluctuation in progeny production and sex ratio.
Considering female progeny production, which is
understood to be an important aspect in mass pro-
duction of parasitoids, the combination involving
S♀ × B♂ scored over others though the treatment
remained inferior in terms of sex ratio. Though in
terms of sex ratio the combinations of B♀ × S♂
and S♀ × S♂ were significantly superior, which
underlines their importance at the present junc-
ture, they do not assume importance in view of
significantly fewer female progenies. Therefore,
considering the importance of female progeny
production, the mating combinations that assume
significance were in the following order: B♀ ×
B♂ > S♀ × B♂ > S♀ × S♂ > B♀ × S♂.
The probable reason for lower progeny pro-
duction in the mating combination of B♀ × S♂
could be that big females generally show con-
siderable reluctance to accept small males for
mating. In the absence of adequate mating, the
urge for mating continues with female and, ob-
viously, the urge for oviposition remains at low
level. In a separate study, we have observed that
the virgin female delays oviposition for a consid-
erable period of time (1–2 days) by which time
its progeny production ability seems to reduce
considerably. But when mating is allowed, the
female oviposits readily. It is, therefore, obvious
that for the production of more progenies the fe-
male needs to get her mating urge fulfilled first.
Random-mated females of parasitoid have
exhibited greater vigor as evidenced by signifi-
cantly more number of host pupae parasitized,
higher number of progenies produced, and the
highest sex ratio compared to the females in sib
and conspecific mating combinations. These pa-
rameters, except sex ratio, with conspecific mat-
ing combinations too are significantly superior to
those with sib mating. Decline in sex ratio among
the conspecifics is due to reduced production of
females relative to males.
The observations recorded from random and
conspecific mating combinations clearly estab-
lish the fact that outbreeding is undoubtedly su-
perior to inbreeding in Trichopria sp. from the
viewpoint of progeny production and progeny
sex ratio. Nevertheless, significant increase in sex
ratio in the progenies produced by random-mated
females can be construed as a distinct advantageTable 2 Effect of sib, conspecific, and random mating on the progeny production of Trichopria sp
Mating
combinations
No. of puparia
parasitizedaDevelopmental
duration (days)Progeny production (no.) Sex ratio
Male Female Total (♀♀/♂)
Sib mating 2.00 ± 0.00d 22.12 ± 0.12 51.25 ± 1.43d 63.50 ± 1.55e 114.75 ± 1.97d 1.25 ± 0.14c
♀A × ♂B 3.00 ± 0.00c 22.25 ± 0.16 135.62 ± 1.23b 176.75 ± 0.88c 312.37 ± 1.76c 1.29 ± 0.01c
♀B × ♂A 3.00 ± 0.00c 22.37 ± 0.18 136.62 ± 0.88b 172.50 ± 1.51d 309.12 ± 0.85c 1.25 ± 0.01c
Random mating4.00 ± 0.00b 22.37 ± 0.18 93.12 ± 1.04c 240.12 ± 0.74b 333.25 ± 0.97b 2.57 ± 0.03b
F test NS
Data are the means of ten replications (mean ± SE)
Mean values followed by the same superscript in columns are not significantly different from each other (P > 0.05)
Sib mating—mating among the progeny of same mother
Conspecific: ♀A × ♂B—mating of female progenies of mother A and male progenies of mother B
Conspecific: ♀B × ♂A—mating of male progenies of mother A and female progenies of mother B
Random mating—mating between male and female progenies of several mothers
NS nonsignificant
Significant at 1 %
aOut of four puparia provided for parasitism