Life parameters including pre-oviposition, oviposition and larval &
pupal periods, adult male and female longevities ,and generation period
were recorded for the red palm weevil, Rhynchophorus ferrugineus
Olivier reared on the sugarcane stem pieces (Diet,1) and other 3 artificial
diets depending mainly on ground sugarcane ,(diet 2); ground corn , (diet
3) and ground mixture of sugarcane and corn (diet 4) . In the laboratory at
28±1°C and 75±5% R.H. , the effects of all diets on total proteins ,
carbohydrates and lipids were also determined in the last instar larvae
.Larvae fed on diet 2 ( ground sugarcane + additives ) exhibited shortest
larval duration ( 86.30 days ) , while diet 3 ( ground corn + additives)
caused the longest larval period ( 128.35 days ) . Shortest and longest
pupal periods resulted also from feeding on diet 2 and diet 3 ( 15.3 and
21.75 days , respectively ) . On the other hand , male and female
longevities were the longest and shortest when previous larvae were fed
on diet 2 and diet 3 ( 50.4 and 38.4 days for males and 48.0 and 36.8 days
for females , respectively . The sex – ratio was almost 1:1 with all diets ,
except diet 2 which led to more females ( 1 male : 1.5 female ).Eggs of R.
ferrugineus hatched after about 4 days , but this period was , significantly
, shorter ( 3.35 days ) by rearing on diet 2 . Highest hatch ability
percentage ( 93.61 % ) resulted from rearing on the same diet .
Chemical analyses of last larval instar content indicated that the
highest total contents of proteins ( 51.87 mg / g ) , carbohydrates (105.0
mg / g ) and lipids ( 21.13 mg / g ) were obtained by rearing on diet2,
diet 1 and the control ( natural feeding on palm ), respectively . |
