Quantitative survey of stored products mites infesting wheat flour in Jeddah Governorate

Abstract

In this study, a faunistic survey of mites was conducted in different product stores such as bakeries, warehouses, mills, department stores and houses during a nine month study period (October 2009 to June 2010), in Jeddah governorate. The survey was carried out on wheat flour as different samples 150 gm each were collected monthly from three regions; North, Middle and South. The results of the current study identified five species of mites belonging to four families:Dermatophagoides farinae (Pyroglyphidae), Acarophenax tribolii (Acarophenacidae), Cheyletus malaccensis (Cheyletidae), Blattisocius tarsalis and Blattisocius keegani (Ascidae). The mites’ counts ranged from 0.15 to 20.44 mites/150 gm wheat flour. The highest counts for the majority of mites species collected from the three regions were recorded during the months of November, December, January and February, according to the decreasing degrees of temperature and relative humidity during these months. D. farinae was the most dominant species in all samples collected from the three regions, followed by A. tribolii in samples from North and Middle. The predatory species C. malaccensis was detected in three regions but in few numbers, whereas, B. tarsalis and B. keegani were detected only in samples from the South. These results indicate the effect of temperature and relative humidity on the distribution density of stored products mites. Key words: Stored products mites, quantitative survey, wheat flour, temperature, relative humidity.