Do Size and Age of Female Trichopria Sp. Influence Longevity, Reproductive Performance ... 43
A considerable enhancement in the parasitoid
female longevity was recorded in big females
indicating that big parasitoid females have an
inherent potential to live longer than small
females. This was also observed in A. zwaelferi
(West et al. 1996 ), A. minuta (Visser 1994 ), and
A. kamali (Sagarra et al. 2001 ). The possession
of potential by Trichopria sp. to live longer could
be considered as one of the fitness characteristics
of the parasitoid.
The influence of parasitoid age on reproduc-
tive efficiency was evaluated by offering 3-day-
old puparia of E. bombycis to 1–8-day-old fe-
males of Trichopria sp. at 1:4. It was found that a
number of puparia parasitized by each of the par-
asitoid females remained similar irrespective of
the age of the parasitoid females, indicating that
the age of the parasitoid does not influence the
rate of parasitism. However, the parasitoid age
did have an influence on progeny production with
female and total progeny production decreasing
as parasitoid age increased. The reason for de-
crease in progeny production with parasitoid age
seems to be associated with parasitoid fecundity,
with older ones being less fecund compared to the
younger ones. A negative relationship between
the parasitoid sex ratio and parasitoid age also has
been observed based on production of relatively
more female progenies by younger parasitoid fe-
males and this decreased relative to male prog-
enies as the parent female age advanced. Tricho-
pria sp. is a proovigenic parasitoid with short
adult life span. It is quite possible that the para-
sitoid female’s ability to contract the spermatheca
to ensure the passage of sperms into the common
oviduct for fertilizing the eggs has declined.
Three distinct effects in the rate of parasitism
vis-a-vis parasitoid female age have been re-
ported. Singh et al. ( 1997 ) using Trichomelopsis
apanteloctena and Kumar et al. ( 1990 ) working
on N. thymus have recorded no significant ef-
fect of parasitoid age on the rate of parasitism.
In the second category of effect, Amalin et al.
( 2005 ) have demonstrated an increase in the rate
of parasitism in young females of C. etiennei. In
the third category of effect, the rate of parasit-
ism by Glyptapanteles flavicoxis decreased as
the parasitoid age advanced (Hu et al. 1986 ). The
observations are that the rate of parasitism by
Trichopria sp. remained almost similar and are
in agreement with those documented by Kumar
et al. ( 1990 ) and Singh et al. ( 1997 ).
There are quite a few reports available on the
influence of parasitoid age on progeny produc-
tion and sex ratio. That the parasitoid females
are more fecund and/or efficient in progeny pro-
duction when they are young has been recorded
in T. chilonis (Guang and Oloo 1990 ), C. gran-
dis (Greenberg et al. 1995 ), C. curvimaculatus
(Hentz 1998 ), and A. reticulatus (Honda 1998 ).
In contrast, Kumar et al. ( 1990 ) observed nonsig-
nificant influence of parasitoid age on progeny
production in N. thymus. Significantly superior
sex ratio has been realized in the progenies pro-
duced by younger parent females of B. intermedia
(Barbosa and Frongillo 1979 ), B. lasus (Simser
and Coppel 1980 ), T. chilonis and T. astriniae
(Hirashima et al. ( 1990 ) and T. minutum (Leate-Table 2 Effect of size of Trichopria sp. female on its reproductive performance
Parasitoid size
(mm)a
No. of puparia
parasitizedbDevelopmental
duration (days)Progeny production (no.) Sex ratio
Male Female Total (♀/♂ )
Big
(1.997 ± 0.01)
3.00 ± 0.00 22.30 ± 0.15 56.00 ± 0.94 233.40 ± 1.07 288.40 ± 1.35 3.65 ± 0.37Small
(1.271 ± 0.00)
2.10 ± 0.31 22.30 ± 0.15 36.60 ± 1.40 122.70 ± 0.89 159.30 ± 1.70 3.37 ± 0.12t-test NS NS
Data are the means of 10 replications (mean ± SE)
NS nonsignificant
- Significant at 1 %
a Big and small parasitoid females differed significantly in their body length
b Out of four puparia provided for parasitism