| Hypoaspis aculeifer (Acari: Laelapidae) population fluctuation in Khorasan Razavi saffron fields, Iran |
| Paper ID : 1132-IPCA5 (R2) |
| Authors |
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Somayeh Fathi1, Mohammad Nateq Golestan *2, Hashem Kamali2, Ali Ahadiyat3 1Department of Plant Protection, Science and Research Branch, Islamic Azad University, Tehran, Iran; 2Plant Protection Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad, Iran 3Department of Plant Protection, Science and Research Branch, Islamic Azad University, Tehran, Iran |
| Abstract |
| Saffron (Crocus sativus L.), as the most expensive spice in the world, is recognized as a strategic agricultural crop in Iran, accounting for approximately 90% of global production and export of this high-value commodity. Hypoaspis (Gaeolaelaps) aculeifer (Canestrini, 1883) (Acari: Laelapidae) is a soil-dwelling predatory mite known for it is considered one of the key natural enemies of saffron bulb mites,Rhizoglyphus robini Claparède, 1869(Acari: Acaridae), in Iranian saffron cultivation. In Iran, there are no approved or registered pesticide applications for saffron cultivation (except for two herbicides) and national regulatory bodies such as the Ministry of Agriculture Jihad and the Plant Protection Organization prohibit pesticide use by farmers in saffron production. In light of this restriction, the significance of biological control agents against the saffron bulb mite, as well as investigating their population dynamics, is increasingly emphasized as a sustainable pest management strategy. In order to investigate the population fluctuation of Hypoaspis aculeifer, a study was conducted in five infected 5-year-old saffron fields in Razavi Khorasan, Iran (Dargaz, Mashhad, Gonabad, Torbat Heydariyeh, and Quchan) during 2022. Saffron corms (200–300 grams per point) were sampled bimonthly from five marked points and processed in the laboratory using a detergent-based washing method (2% soap and 1% bleach) to extract mites. The suspension was filtered through a series of four stainless-steel sieves (850 μm, 500 μm, 212 μm, and 75 μm), and mites were collected in ethanol and examined under a stereo microscope. The direct influence of both developmental stages of saffron corm mite on the population growth of the predatory mite was assessed. The population growth rate of adult predatory mites reached its minimum on August 9th and peaked on January 3th. The relationship between adult predatory mites and the adult and nymphal stages of saffron bulb mites was analyzed using a logistic regression model. However, the impact of nymphal stages on predator development was more pronounced, with higher standardized coefficients in both saffron corms (Beta = 0.444) and surrounding soil (Beta = 0.782) , compared to the adult stage, which exhibited lower effects in corms (Beta = 0.289) and soil (Beta = 0.281). Based on the results, changes in the saffron mite nymphal population has more direct impact on the predatory mite population, and it can be concluded that the predatory mite has host preference to the saffron mite nymphal stages. Considering the maximum population density of the predatory mite in January, which physiologically coincides with the peak of saffron vegetative growth, this time period is suggested as the appropriate time to use this predator in the field for saffron bulb mite’s management. |
| Keywords |
| logistic regression, pest management, predatory mite, Rhizoglyphus robini, saffron corms |
| Status: Abstract Accepted |
