Influence of acclimation to sublethal temperature on heat tolerance of <i>Tribolium castaneum</i> (Herbst) (Coleoptera: Tenebrionidae) exposed to 50°C

<div><p><i>Tribolium castaneum</i> (Herbst) (Coleoptera: Tenebrionidae) is a serious pest of stored agricultural products and one of the most common insects found in grain storage and food processing facilities. Heat treatment has been revisited to control stored-product insects as a potential alternative to methyl bromide for disinfesting mills and food-processing facilities. The influence of acclimation of <i>T</i>. <i>castaneum</i> adults, pupae, larvae, and eggs to sublethal temperatures of 36, and 42°C on their subsequent susceptibility to lethal temperature of 50°C was respectively investigated. The acclimation of <i>T</i>. <i>castaneum</i> eggs, larvae, pupae, and adults to 36, and 42°C significantly decreased their subsequent susceptibility to lethal high temperature of 50°C. The influence of acclimation to 42°C was significantly greater than that of acclimation to 36°C. The most influential acclimation times at 42°C for mortality of <i>T</i>. <i>castaneum</i> eggs, larvae, pupae, and adults were 15, 5, 5, and 5 h, respectively, and their corresponding mortality were 41.24, 5.59, 20.19, and 4.48%, compared to 100% mortality of <i>T</i>. <i>castaneum</i> eggs, larvae, pupae, and adults without acclimation when exposed to 50°C for 35 min, respectively. The present results have important implications for developing successful heat treatment protocols to control <i>T</i>. <i>castaneum</i>, improving disinfestation effectiveness of heat treatment and understanding insect response to high temperatures.</p></div

Repeated measures analysis of variance within subject effects for the contact toxicity of <i>Alpinia</i> extract against <i>L</i>. <i>serricorne</i> adults at the doses of 0, 0.02, 0.04, 0.08 and 0.16 μL/cm² after 12, 24, 48 and 72 h exposure, respectively.

<p>Repeated measures analysis of variance within subject effects for the contact toxicity of <i>Alpinia</i> extract against <i>L</i>. <i>serricorne</i> adults at the doses of 0, 0.02, 0.04, 0.08 and 0.16 μL/cm² after 12, 24, 48 and 72 h exposure, respectively.</p

The effect of acclimation to 42°C on mortality (%) of <i>T</i>. <i>castaneum</i> pupae exposed to 50°C.

<p>The effect of acclimation to 42°C on mortality (%) of <i>T</i>. <i>castaneum</i> pupae exposed to 50°C.</p

The effect of acclimation to 42°C on mortality (%) of <i>T</i>. <i>castaneum</i> adults exposed to 50°C.

<p>The effect of acclimation to 42°C on mortality (%) of <i>T</i>. <i>castaneum</i> adults exposed to 50°C.</p

Repeated measures analysis of variance between subjects effects for the repellent activity of <i>Alpinia</i> extract against <i>L</i>. <i>serricorne</i> adults at the doses of 0.025, 0.05, 0.10 and 0.20 μL/cm² after 12, 24, 36 and 48 h exposure, respectively.

<p>Repeated measures analysis of variance between subjects effects for the repellent activity of <i>Alpinia</i> extract against <i>L</i>. <i>serricorne</i> adults at the doses of 0.025, 0.05, 0.10 and 0.20 μL/cm² after 12, 24, 36 and 48 h exposure, respectively.</p

The effect of acclimation to sublethal high temperature on mortality (%) of <i>S</i>. <i>zeamais</i> exposed to 43°C.

<p>The effect of acclimation to sublethal high temperature on mortality (%) of <i>S</i>. <i>zeamais</i> exposed to 43°C.</p

The effect of acclimation to 36°C on mortality (%) of <i>T</i>. <i>castaneum</i> pupae exposed to 50°C.

<p>The effect of acclimation to 36°C on mortality (%) of <i>T</i>. <i>castaneum</i> pupae exposed to 50°C.</p

Two-way ANOVA analysis for the number of <i>L</i>. <i>serricorne</i> in whole wheat flour packaged with nonwoven cloth bags and kraft paper bags after 45 days storage at 27 ± 2°C and 75 ± 5% relative humidity.

<p>Two-way ANOVA analysis for the number of <i>L</i>. <i>serricorne</i> in whole wheat flour packaged with nonwoven cloth bags and kraft paper bags after 45 days storage at 27 ± 2°C and 75 ± 5% relative humidity.</p

The effect of acclimation to 42°C on mortality (%) of <i>T</i>. <i>castaneum</i> larvae exposed to 50°C.

<p>The effect of acclimation to 42°C on mortality (%) of <i>T</i>. <i>castaneum</i> larvae exposed to 50°C.</p

The number of <i>L</i>. <i>serricorne</i> population in whole wheat flour packaged with nonwoven cloth bags and kraft paper bags after 45 days storage at 27 ± 2°C and 75 ± 5% relative humidity.

<p>The number of <i>L</i>. <i>serricorne</i> population in whole wheat flour packaged with nonwoven cloth bags and kraft paper bags after 45 days storage at 27 ± 2°C and 75 ± 5% relative humidity.</p