Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz (1999) 72, 113-121

Inga Mewis and Ch. Ulrichs (1999)
Wirkungsweise amorpher Diatomeenerden auf vorratsschädliche Insekten. Untersuchung der abrasiven sowie sorptiven Effekte
[Effect of diatomaceous earths on storage insect pests. Studies on abrasive and sorption properties]
Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz 72 (5), 113-121
Abstract: The present study examined the morphological and physiological effects of amorphous diatomaceous earth against the stored product pests S. granarius, T. molitor and T. confusum. Diatomaceous earth, namely Fossil Shield® and Dryacide® increased the mortality rate of this insects. After contact with Fossil Shield® the individuals of S. granaries had significant lost of weight and reduced their water content respectively. This showed that silica dusts break the water barrier of the cuticle. However, it increases the transpiration rate of water across the cuticle and the insect died past several times through dehydration. As well, an addition of food affected the effectiveness of dusts against insects. A lot of stored product beetles will be able to produce metabolic water of feed substrates. This ability protects and weaves contrary to the loss of water. Diatomaceous earths can be effective primarily through the sorptive properties of the hygroscopic particles. One day after dust treatment a significant weight loss of T. molitor pupae was recorded. The exposure to the silica dust Fossil Shield® caused partly an incomplete metamorphosis and death of the individuals. Pupae dipped in Fossil Shield® or abrasive aluminium dust and rolled for further five minutes, reduced not significant higher their weight as unrolled exuvial stages. The morphological analyses of treated insects under the Scanning Electron Microscope showed, that the dust covered the hole integument. Partly, the silica particles sunk into the cuticle. After application of Fossil Shield® at the cuticle of adults, T. molitor, did not show any wax layer. Also it could not be found once blocked by stigma of the mealworm. The dust particles accumulated around the respiration openings and they partly overgrew.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: German)
Link to article at publishers website
Database assignments for author(s): Christian Ulrichs, Inga Mewis

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tribolium confusum		Germany
	Sitophilus granarius		Germany
	Tenebrio molitor		Germany