This work aimed to evaluate the efficacy of modified atmosphere
(MA) enriched with Argon gas as an alternative measure for controlling four
stored dates pests, two from order: Lepidoptera, Ephestia cautella (Walker) &
Plodia interpunctella (Hübner) and two from order Coleoptera; Oryzaephilus
surinamensis Linnaeus & Stegobium paniceum (L.) and its effect on some
enzymes activity of tested insects. Argon gas concentrations of (60, 80 and
100 %) had been tested against the four mentioned insects at different
exposure times ranged from 3 to 144 hrs. The results revealed that
Lepidopterous were more sensitive to Argon gas than Coleopterous. Also, data
indicated that not all tested insects have the same sensitivity to Argon gas.
Obtained results indicated that the reduction % of adult emergence increased
by increasing exposure duration and or concentration. At the concentration of
100 % Argon, data reported that the larvae of E. cautella were the most
susceptible and reached a 100% reduction after 12 hrs. While the adults of O.
surinamensis was the most tolerant insect stage to Argon gas where reached
74.60 % reduction after 72 hrs. Exposure of P. interpunctella and O.
surinamensis to LT 50 of Argon increased the activity of two defensive
enzymes within tested insects, Acid phosphatase, &Carboxlesterases. and
decreased the activity of LDH enzyme. |
