To avoid the problem of using methyl bromide and synthetic
insecticides for controlling stored product pests, an alternative technique. i.e. the
application of modified atmospheres, is available. Thus, this study aims lo
evaluate the efficacy of using a modified atmosphere of approximately 1% 02
plus 99% N2 against some stored product insects, namely; the rice weevil
iSitophilus oryzae (L.)1. the lesser grain borer LRhizopertha dominica (F.)I and
the red flour beetle ITribolium castaneum (l-{erbst.)1. Experiments were carried
out in the laboratory at 26 and 6°C.
Results revealed that the time required to achieve certain kill for the
various stages of the three insect species was considerably longer at knet
temperature than at higher one.
Marked differences in the susceptibilites of the various stages of the
insect species were obtained, whereas the adult stage was the most sensitive one.
T. castaneum was the most susceptible species.
The LT99-values recorded orvzae were 6.9, 47.3, 63.4 and 102 days
at 26°C and 10.2, 73. 17 and 108 days at 6°C for the adult, pupa, larva, and egg,
respectively. The corresponding values of R. dominica were 5.8, 30.4, 82.3 and
38.5 days at 26°C and 32.1. 100, 143 and 132 days at 6°C, respectively. While,
in case of T castaneum, these values were 2, 29.3, 13.2. and 19.6 dais at 26°C
and 15.1, 45.2, 31.2 and 47.7 days al 6°C for the adult, pupa. larva and egg.
respectively.
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