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Sudan Journal of Agricultural Research
The life history of Oryzaephilus surinamensis (L.)
and O. mercator (Fauv.) (Silvanidae: Coleoptera) reared on Gondaila and
Barakawi date cultivars under ambient laboratory conditions
Susan M. A. El-Nazir , E. El-Khdir and M. E. Shazali
Abstract
The pre-oviposition periods, fecundity and oviposition periods for the two
store pests Oryzaephilus surinamensis and O. mercator were markedly
affected by temperature, relative humidity and date cultivars (Gondaila
and Barakawi). The highest mean number of eggs of O. surinamensis was
61.2, the oviposition period continued for more than 9 months and some
adults lived for up to 10 months when the experiment was started in August
(warm and humid month). Low temperature prolonged the incubation period,
while relative humidity seemed to have little effect. However, both
temperature and relative humidity affected egg hatching. The shortest mean
larval-pupal development periods (21.4 and 31.0 days) and the highest
growth indices (0.092 and 0.056) were recorded at a mean temperature and
relative humidity of 36.3°C and 49.9% (August-September) on Gondaila and
Barakawi, respectively. The longest mean larval-pupal period was 54.5 days
on Gondaila at a mean temperature and relative humidity of 25.0°C and
32.4% (January-March). For O. mercator, the highest mean fecundity was
32.7 eggs when the experiment was conducted in August. The oviposition
period was extended up to three months. Some adults lived for about 5
months. The shortest mean larval-pupal development periods (26.2 and 36.2
days) and the highest growth indices (0.075 and 0.049) were recorded at a
mean temperature and relative humidity of 36.3°C and 49.9%
(August-September) on Gondaila and Barakawi, respectively. The longest
mean period was 48.3 days on Gondaila at 33.5°C and 19.5% R.H.
(March-May). However, the mortality for both species was 100% on Barakawi
at a mean temperature and relative humidity of 25.0°C and 32.4%
(January-March) and 33.5°C and 19% (March-May) observation periods.
Sudan Journal of Agricultural Research Vol. 9 (2007) PP. 99-107
