Entomologia Experimentalis et Applicata (2001) 101, 33-39

Marilyn Rigaux, Eric Haubruge and Paul G. Fields (2001)
Mechanisms for tolerance to diatomaceous earth between strains of Tribolium castaneum
Entomologia Experimentalis et Applicata 101 (1), 33-39
Abstract: Fourteen strains of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) had mortalities ranging from 5 to 100% when exposed to diatomaceous earth at 600 ppm for seven days. The most tolerant strain had a lethal dose for 50% of the population (LD₅₀) of 413 ppm and the most susceptible strain had a LD₅₀ of 238 ppm. Adults of the tolerant strain were lighter (2.0 mg) than the susceptible strain (2.6 mg). Tolerant adults lost water at lower rate (6 [mgr]g h^-1 than susceptible adults (12 [mgr]g h^-1), when held in wheat treated with 600 ppm diatomaceous earth for 24 h, than held at 5% r.h. with no food. Tolerant adults that were not exposed to diatomaceous earth lost water at a lower rate (3 [mgr]g h^-1) than susceptible adults (5 [mgr]g h^-1). Both strains, exposed and not exposed to diatomaceous earth died when their water content was between 33 and 37% of their total weight. Insects taken directly from the cultures had 52% (tolerant) and 53% (susceptible) of their total weight as water. Tolerant adults moved slower through grain and across filter paper than susceptible adults. Tolerant adults avoided wheat treated with diatomaceous earth at concentrations as low as 75 ppm, whereas the adults from the susceptible strain did not avoid diatomaceous earth, even at 600 ppm. The consequences of a strain tolerant to diatomaceous earth is discussed with respect to the use of diatomaceous earth to control stored-product insect infestations.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Paul G. Fields

Research topic(s) for pests/diseases/weeds:
control - general
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tribolium castaneum	Stored grain