Persian Journal of Acarology

Abstract Date palm pollen has received considerable attention among various pollen types due to its high nutritional value, availability, and positive effects on predator performance. However, the nutritional quality of date palm pollen can vary significantly depending on its geographical origin. Therefore, this study was conducted to evaluate the effect of geographical variation in date palm pollen quality on the biological performance of Amblyseius swirskii Athias-Henriot. Pollen samples were collected from the same date palm cultivar (Mazafati) at four locations in southern Iran: Bam and Jiroft (Kerman Province) and Rodan and Hajiabad (Hormozgan Province). The shortest pre-adult development was observed on Rodan pollen (6.38 days), and the longest times were observed on pollen from Jiroft (7.71 days) and Bam (7.69 days). Fecundity was significantly higher in individuals fed Rodan pollen (40.62 eggs/female) than those fed other pollens. The highest pre-adult mortality occurred in individuals reared on Bam pollen, followed by Jiroft pollen. The highest intrinsic (r) and finite (λ) rates of increase were obtained on Rodan pollen (0.181 and 1.199 day-1, respectively), while the lowest values were recorded on Bam pollen (0.117 and 1.124 day-1, respectively). Similarly, Rodan pollen exhibited the highest net (R0) and gross (GRR) reproductive rates, while the lowest values were observed on Bam and Jiroft pollens. Rodan pollen had the shortest mean generation time (T) (16.45 days). Rodan pollen also had the highest protein content (43.18%), showing a significant difference compared to the other pollens. Our findings demonstrate that geographical origins of the date palm can directly affect its pollen quality and indirectly affect the biological performance of the predatory mite.

Abstract The successful rearing of predators and parasitoids is crucial for the effectiveness of biological control programs. A notable challenge in rearing phytoseiid mites, specifically Amblyseius swirskii and Transeius wainsteini, is preventing mold contamination in their diets. This study evaluated the efficacy of three herbal powders, thyme, green tea, and lemongrass, as well as the chemical agent, calcium propionate, in suppressing mold development.  Experiments were conducted using a diet composed of cattail pollen and rice husks under controlled laboratory conditions (25 ± 1 °C, 65 ± 5% RH, and 16L: 8D h photoperiod). A diet without any additive agents served as the control. To quantify mold growth within each rearing unit, a numerical index, the Mold Contamination Index (MCI), ranging from 0 to 4 was employed. The results demonstrated that calcium propionate was significantly more effective than the other treatments, achieving complete inhibition of mold development (MCI = 0), compared to the control treatment (MCI = 1.45 and 1.40 for A. swirskii and T. wainsteini, respectively). The incorporation of calcium propionate into the diet significantly enhanced population growth rates, reaching 31.95% for A. swirskii and 23.57% for T. wainsteini, compared to the control treatments, which showed increases of only 2.3% and 1.74%, respectively, over one month. In contrast, the addition of botanical powders did not inhibit mold growth and was associated with a decrease in population growth rates relative to the controls. The mixture of cattail pollen, rice husks, and calcium propionate provided sufficient nutritional support, facilitating population growth of both mite species. Consequently, the populations expanded to a total of 494.3 and 368.6 individuals across all developmental stages, originating from an initial density of 15 adult mites, within one month for A. swirskii and T. wainsteini, respectively. This study presents a promising strategy for managing mold in phytoseiid mite diets, ultimately fostering healthier rearing conditions.

Abstract In this study, life table analysis was performed to evaluate the nutritional value of proso millet and saffron pollen grains as a dietary supplement for rearing and conservation of Neoseiulus cucumeris Oudemans and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). According to our results, developmental time did not differ between the two pollen diets for either predatory mite. Amblyseius swirskii completed immature development significantly faster than N. cucumeris on both pollen diets. Fecundity of both predator females, offered saffron pollen, was significantly higher than that of females given proso millet pollen, however, N. cucumeris females had higher fecundity than A. swirskii females. Comparisons between two predators indicated that N. cucumeris females had a higher R₀, GRR, r, and λ than A. swirskii on saffron and proso millet pollen. There were no significant differences in intrinsic rate of increase (r) and finite rate of increase (λ) of N. cucumeris between the two pollen diets, although significantly higher values of r and λ were observed in A. swirskii reared on saffron pollen than those fed on proso millet pollen. This suggests that saffron and proso millet pollen could be a viable alternative food source for these predators, particularly during times when prey in the field is scarce or absent. Additionally, our results indicate that saffron pollen can be effectively used for mass rearing and/or conservation of these predatory mites in biological programs.

Abstract The predatory mite, Neoseiulus barkeri Hughes is one of the most important phytoseiid mites to control phytophagous mites. The effect of different diets such as, corn pollen, walnut pollen, sunflower pollen, date pollen, bee pollen along with the two-spotted spider mite (Tetranychus urticae Koch) eggs on life table parameters of the predatory mite was determined on strawberry detached leaves in Petri dishes. The experiments were carried out under laboratory conditions at 27 ± 1°C, 16L: 8D h photo-period and 70 ± 5% RH. The individuals of  the predatory mite were collected from cucumber field infested with the two-spotted spider mite of Khoramabad, Lorestan Province. The results indicated that mean preimaginal developmental time was the highest on sunflower pollen and bee pollen than the preimaginal developmental time on the other tested pollens. The developmental time of adult of  N. barkeri when fed with bee pollen (10.0 and 9.25 days for female and male, respectively) is longer than when it fed on the other diets. The fecundity rate of predatory mite on different diets did not show any significant difference. The intrinsic rate of increase (r) of the predatory mites fed with sunflower pollen (0.212 d^-1), date pollen (0.225 d^-1) and corn pollen (0.224 d^-1) were higher than the other treatments. With attention to observed results, corn pollen, sunflower pollen and date pollen were suitable alternative food for the mass rearing of this predator.