Abstract:
Demographic analyses of dubas bug,
Ommatissus lybicus
de Bergevin, (Hemiptera:
Tropiduchidae), reared on five date palm varieties
(Zahdi, Mazafati, Piarom, Khasi, and
Shahani) were constructed under laboratory conditio
ns at 27±1ºC, 70±5% RH, and a
14:10 hours (L: D) photoperiod. Data were analyzed
based on the age-stage, two-sex life
table theory to take the variable developmental rat
e among individuals and both sexes
into consideration. Results showed that different v
arieties of date palm influenced
development time and fecundity of dubas bug. The to
tal pre-adult developmental time
was the shortest on Zahdi (85.21 days) and the long
est on Khasi (88.39 days). The
longevities of both male and female adults on diffe
rent varieties were significantly
different. The mean fecundity per female was signif
icantly higher on Zahdi (78.62 eggs)
and Mazafati (68 eggs) than on Shahani (43.53 eggs)
and Khasi (46.32 eggs). The highest
and lowest net reproductive rates were obtained on
Zahdi (40.58 offspring per individual)
and Shahani (16.88 offspring per individual), respe
ctively. The intrinsic rates of increase
were 0.0401, 0.0368, 0.0355, 0.0312 and 0.0301 per
day on Zahdi, Piarom, Mazafati, Khasi
and Shahani, respectively. The mean generation time
s ranged from 92.78 days reared on
Zahdi to 95.25 days on Mazafati. According to resul
ts obtained in this study, Shahani and
Khasi were the most resistant varieties while Zahdi
was the most susceptible variety to
dubas bug among the varieties tested.
Keywords:
Demography, Date palm variety, Dubas bug
.
