Influence of Physico-Chemical Traits on Host Preference of the Cigarette Beetle, <i>Lasioderma serricorne</i>, among Commercial Tobacco Types

The cigarette beetle, Lasioderma serricorne, is a major stored-product pest causing significant economic damage to tobacco. While it exhibits distinct preferences for different tobacco types, the mechanistic basis for this selectivity remains inadequately explored. This study investigated the feeding preference, consumption, and utilization of four commercially important tobacco types; Flue-cured Virginia (FCV), Sun-cured Rustica (SCR), Dark Air-cured (DAC), and Air-cured Burley (ACB) by L. serricorne larvae and adults and correlated these biological responses with key physico-morpho-chemical plant traits. Bioassays revealed significant differences in consumption and utilization among the tobacco types. FCV was the most consumed and utilized type by larvae, while ACB was the least preferred by both life stages. Consumption was strongly and positively correlated with utilization. Correlation analyses identified that larval consumption and utilization were significantly positively influenced by moisture content, total sugars, reducing sugars, and starch, but were negatively affected by pH and ash content. Notably, nicotine and leaf thickness showed no significant correlation with consumption. For adults, consumption was negatively correlated with crude fiber, while utilization was positively correlated with chloride content. The comprehensive chemical profiling showed distinct compositions among the types, with FCV being characterized by high sugar content and ACB by higher crude fiber and nicotine. The results demonstrate that the susceptibility of tobacco types to L. serricorne is not governed by a single factor like nicotine, but by a complex interplay of phagostimulatory sugars and deterrent factors like fiber and ash. These findings provide a scientific basis for selecting less susceptible tobacco varieties and developing targeted strategies for Integrated Pest Management (IPM) in stored tobacco.