Evaluation of natural diatomaceous earth deposits from south‐eastern Europe for stored‐grain protection: the effect of particle size

Abstract

Deposits from south-eastern Europe appeared to be very effective against the tested species, and therefore this region should be further evaluated as a source of development of commercial products. Particle size is a physical property that should always be taken into account during the DE manufacturing process, as it can strongly influence the insecticidal action of a given product.

Effect of Beauveria bassiana mixed with diatomaceous earth on mortality, mycosis and sporulation of Rhyzopertha dominica on stored wheat

“…The efficacy of DE depends upon its contents, especially silicon dioxide (Fields and Korunic 2000;Vayias et al 2010) and the relatively reduced level of adult mortality of R. dominica could be due to lower silicon dioxide concentration in Diafil 610 as compared with the most effective commercially available DE products.…”

Insecticidal Potential of Natural Zeolite and Diatomaceous Earth Formulations Against Rice Weevil (Coleoptera: Curculionidae) and Red Flour Beetle (Coleoptera: Tenebrionidae)

“…Differences in efÞcacy, obtained for the DE-based inert dusts used, can likely be explained by different size fractions of particles with diameter up to 13 m (95.33% for DE S-1 and 81.03% for DE S-2), considered as one of the most important size fractions with respect to the inert dust insecticidal activity. In addition, Vayias et al (2009) have found, while testing the efÞcacy of DE formulations from South-Eastern Europe, that smaller particles are more effective against three stored-product Coleopteras, although signiÞcant differences in efÞcacy between the fractions consisting of particles 0 Ð150 m in size and those of Ͻ45 m were not always observed. Additionally, higher total insect mortality achieved using DE inert dusts than that applying NZ formulations is obvious, both different SiO 2 structures and granulometric composition fractions of particles with diameter up to 13 m (95.3 and 81.0% for DE S-1 and DE S-2; 49.0 and 51.9% for NZ and NZ ModiÞed) can be notiÞed as possible reasons.…”

“…Previous studies revealed that the area of South-Eastern Europe (Slovenia, Croatia, Greece, Macedonia, and Serbia) has very rich deposits of DE, which effectiveness against stored-product pests is similar to those DE based formulations registered worldwide (Korunić 1997, Vayias et al 2009, Athanassiou et al 2011. Contrary to DEs, composed mainly of amorphous silica (Golob 1997, Korunić 1998, zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earths (Christidis et al 2003, Sprynskyy et al 2005.…”

“…Inert dusts have low mammalian toxicity and do not affect signiÞcantly the quality of treated products if applied at low rates (Korunić et al 1996. The efÞcacy of inert dusts and especially of diatomaceous earth (DE) formulations may differ depending on insect species (Korunić 1997Fields and Korunić 2000), silicon dioxide content and structure (crystalline or amorphous), particle size distribution (Korunić 1998, Subramanyam and Roesli 2000, Vayias et al 2009), as well as on air and substrate moisture content, temperature, and duration of insect exposure to the formulations used (Fields and Korunić 2000;Arthur 2001Arthur , 2002Fields et al 2003;Athanassiou et al 2005;Kavallieratos et al 2005;Vardeman et al 2006). Geographical origin of DE may affect its insecticidal activity as well (Vayias et al 2009).…”

Applications of natural zeolites on agriculture and food production

“…Temperature, relative humidity, method of treatment, insect species (the developmental stage, size of which greater surface area to volume ratio, softness of wax layers, hairiness, susceptibility and physical mobility) and plant species (plant biology) assess the potential of the product . Furthermore, some dust properties, such as molecular structure, content of silicon dioxide, shape and size of particles, Al/Si ratios, sorption ability and geographical origin, also affect the insecticidal potential directly . Inert dust access to the insect body, although not certain, is suggested to follow these paths: (i) spiracle blocking and asphyxiation; (ii) abrasion of cuticle that causes water loss; (iii) ingestion of the dust particles; and (iv) absorption of epicuticular lipids that leads to dessication .…”