The developmental time and rate of immature stages, survival percentage,
longevity, fecundity, and life table parameters of Coccinella undecimpunctata and
Cydonia vicina isis by rearing on cereal aphid, Sitobion avenae were studied under
laboratory conditions. The relationship between female age and fecundity rate of
females was also determined.
The total developmental time from egg hatching to adult eclosion was
9.80±0.19 and 10.30±0.43 days for C. undecipunctata and C. vicina isis. Survival
percentage from egg hatching to adult emergence differed significantly between the
two predators when fed on S. avenae. There was no significant difference in longevity
of females, while there were significant variations in fecundity of females and
longevity of males. Simple linear regression between female age and fecundity rate of
C. undecimpunctata females indicated that there was no relationship between female
age and female fecundity rate. Considering C. vicina isis, there was a negative
relationship between female age and fecundity rate. This means that the fecundity
rate gradually decreased as the age of female increased.
The calculated value of (T) was shorter with C. vicina isis than C.
undecimp < /em>unctata. In contrast, (OT) was shorter with C. undecimpunctata than with C.
vicina isis. In addition, GRR, Ro, rm and A values were higher with C. undecimpunctata
than C. vicina isis. The survivorship (Lx) for female age intervals was high (0.96) with
C. vicine isis, while with C. undecimpunctata, the value of (Lx) was relatively high
(0.92). 'Maximum oviposition rate per female per day (Mx) was 35.88 on ss" day, and
13.62 on 2nd day with C. undecimp < /em>unctata and C. vicina isis.