Efficacy of Modified Atmospheres on Trogoderma granarium (Coleoptera: Dermestidae) and Sitophilus zeamais (Coleoptera: Curculionidae)

Abstract

We investigated the efficacy of two types of modified atmospheres (MA) against adults of the khapra beetle, Trogoderma granarium Everts, and the maize weevil, Sitophilus zeamais Motschulsky, under laboratory conditions. Adults of the above species on wheat were exposed to a carbon dioxide (CO2) concentration of 70% or a low oxygen (O2) concentration of 0.1% for durations of 0.67 (16 h), 1, 2, 4, and 6 d and stored in an environmental chamber set at 28 ± 2°C, 70 ± 5% RH, and a photoperiod of 16:8 (L:D) h. After each exposure interval, immediate mortality and knockdown were recorded, and the surviving or knocked down individuals were transferred to normal atmospheres and returned to the environmental chamber, where survival was recorded 7 d later. In addition, after the immediate and delayed mortality counts, all adults were removed from the substrate, and the number of progeny produced was recorded 60 d later. Both MA conditions totally controlled (100% mortality) the adults of T. granarium and S. zeamais immediately after a 6-d exposure or after a 4-d exposure when delayed mortality was taken into account, showing the postexposure effect of the MA. Moreover, high CO2 was more effective than low O2 for S. zeamais, whereas the reverse was true for T. granarium. The 4-d exposure period was crucial for the production of progeny of both species because after that period surviving insects did not produce offspring. Our results show that both MA conditions can be used with success to control these species.

Field evaluation of hermetic and synthetic pesticide-based technologies in smallholder sorghum grain storage in hot and arid climates

“…When storage insects are exposed to hypoxic and hypercarbic conditions, they usually adapt by reducing their respiration and metabolic rates, and shifting to discontinuous gas exchange cycle where they can take relatively long periods with their spiracles fully closed, hence their desiccation is gradual [36][37][38][39] . In addition, terrestrial insects also lose water when they continually ventilate their tracheal linings when exposed to dry conditions 22 .…”

Combination of Modified Atmosphere and Irradiation for the Phytosanitary Disinfestation of Trogoderma granarium Everts (Coleoptera: Dermestidae)

“…Despite the similarities in response, arthropod mortality is generally greater in response to high carbon dioxide as exposure to the low-oxygen atmosphere [ 62 ]. Furthermore, when elevated CO 2 is added to low-oxygen atmospheres, the additive or synergistic effects have been observed depending on the concentrations and the insect species used [ 62 , 63 , 64 ]. Therefore, a promising treatment may be established by combination low-dose irradiation (save cost and time) with a low-oxygen and high CO 2 atmosphere to further shorten the exposure time (for MA treatment), and to be accepted by all the user (the exporter, importer, regulator) to an alternative to the QPS uses of methyl bromide.…”

Pest Management in the Postharvest Agricultural Supply Chain Under Climate Change

“…In addition, except for work evaluating CO 2 as a modified atmosphere treatment (e.g. Navarro 2012;Vassilakos et al, 2019), no work has looked at elevated levels of CO 2 (at levels relevant for climate change) on other IPM tactic efficacy after harvest. This represents a black box where very little is known about ramifications for stored product IPM tactics.…”