Survey of Mites Associated With Grain Residues and Mixed Flour in Warehouses and Mills in Great Cairo

Abstract

Twenty one mite species belonging to 3 suborders and 11 families were found in grain residues and mixed flour samples collected from warehouses and mills at Great Cairo. They were 12 pest species, 7 predatory and 2 parasitic species. Species commonly found in all inspected materials at all locations were Dermatophagoides farinae Hughes, Tyrophagous putrescentiae (Sch.) and Cheyletus malaccensis Oud. However Acrus siro (Lin), Acarophenax tribolii (New.) and Pyemotes herfsi (Oud.) were often abundant. The remaining species occurred sporadically in the collected materials. Actinedid and acaridid mites were "dominant" and "constant" in mixed flour and grain residues samples, the second group was the most abundant. Whereas gamasid mites was "recedent" and "accidental". Mixed flour taken from Qaliobia Governorate harboured the highest number of mite species (15 species) followed by grain residues from Giza Governorate (13 species). While grain residues taken from Cairo Governorate harboured the lowest number (5 species).The highest infestation level with mites (2677.3 individuals) was recorded in mixed flour at Qaliobia Governorate, while the lowest one (1067 individuals) was found in grain residues at Cairo Governorate. Generally, mixed flour harboured more mite species than grain residues. Most of the collected mite species occurred during autumn and winter except P. herfsi and A. tribolii which were recorded during spring and summer, respectively. Dominance and frequency of occurrence, population fluctuations, effect of temperature and relative humidity on the population dynamics, also the relation between the predators and pests of mites were discussed in details.

Quantitative and Qualitative Losses in Chickpea var. Desi Channa due to Suidasia nesbitti Hughes (Arachnida: Acari)

“…Broken grain material and flour of Desi channa became darker in colour as the population multiplied due to excessive excreta at 150 and 180 days. Earlier studies have concluded that flour provides much larger surface area to mites (Kohli and Mathur 1994) and act as perfect medium for the mite growth (Mahgoob et al 2006) (Seema, 2020) and cowpea (Dalal, 2020) was also reported. Seema (2020) recorded that as the mite number increased to 662.00 mites/5 g grain and 698.00 mites/5 g flour, protein content decreased to 106.133 mg/g in grain and 87.733 mg/g in flour of pearl millet after 180 days.…”

Differential levels of mite infestation of wheat and barley in Czech grain stores

“…Mites are common inhabitants of a wide spectrum of stored products, including grain (Zdarkova, 1967; Sinha, 1979; Athanassiou et al , 2005; Palyvos & Emmanouel, 2006; Krizkova‐Kudlikova et al , 2007) and grain‐based commodities at all stages of processing (Mahgoob et al , 2006), vegetables and fruits (Chmielewski, 1998), and plant seeds (Zdarkova, 1997; Kucerova & Horak, 2004; Dunn et al , 2005). In addition to these habitats, several species inhabit human houses and are present in house dust (Koraiem & Fahmy, 1999) or rubbish (Ottoboni et al , 1992; Russell et al , 2004).…”