Persian Journal of Acarology

Abstract It is well known that cathepsin D (CD) has a fundamental role in the degradation of yolk proteins during embryo development as it has a dual function in embryo feeding and defending against pathogens. Cathepsin D-like activity is revealed during embryogenesis of Hyalomma dromedarii (Acari: Ixodida) tick and attained the highest activity in 3–4 days-old embryos during the cleavage stage and nominated camel tick embryo cathepsin D (CTECD). After purifi-cation by cationic CM-cellulose gel filtration Sephacryl S-300 columns, CTECD turned out to be homogeneous with specific activity of 40 U mg⁻¹ proteins, 7.4 purification factor and 55.3% yield. CTECD molecular mass was deduced from the size exclusion column to be almost 40 kDa. CTECD hydrolyzed the specific synthetic substrate Bz-Arg-Gly-Phe-Phe-Pro-4-methoxy-β-naphthylamide confirming that the enzyme is cathepsin D. Both Zn²⁺ and Pepstatin A were potent inhibitors of CTECD activity. Also, CTECD displayed its maximum activity at pH 2.5 with a pH profile typical for cathepsin D. This study suggests the involvement of CTECD in yolk proteins utilization by the developing embryos as it attained its highest activity in cell cleavage stage. The study of biochemical changes during tick embryogenesis will be helpful in understanding the tick cells adaptability for different pathogens.

Abstract Typhlodromus (Anthoseius) bagdasarjani Wainstein & Arutunjan is an indigenous species naturally inhabiting mulberry and fig trees in urban regions. The current study was conducted to evaluate possible effects of four host plants including cucumber, tomato, eggplant, and watermelon on the functional response of T. bagdasarjani feeding on different densities (2, 4, 8, 16, 32, 64, and 128) of immature stages (larva + protonymph) of Tetranychus urticae Koch. The experiments were conducted under laboratory conditions at 25 ± 1 ℃, 60 ± 5% RH, and a photoperiod of 16:8 (L:D) h. The logistic regression revealed type II functional response on the tomato, eggplant, and watermelon and a type III one on the cucumber. The handling time (T_h) and searching efficiency (a) were estimated using the Rogers equation. The highest and lowest values of T_h in the type II functional response were recorded on the watermelon (0.927 ± 0.061 h) and eggplant (0.632 ± 0.085 h), respectively. Accordingly, the highest and lowest values of searching efficiency in this type of functional response were obtained on the watermelon (0.055 ± 0.009 h⁻¹) and eggplant (0.028 ± 0.005 h⁻¹), respectively. The maximum predation rate (T/T_h) was recorded on the eggplant (37.963 prey/day). On the cucumber, the value estimated for the handling time was 1.341 ± 0.079 h. The maximum predation rate on this host plant was estimated to be 17.90 prey/day. In conclusion, our findings revealed effects of different host plants on the functional response of T. bagdasarjani showing that this species may be more effective in suppressing the population of T. urticae on the cucumber.

Abstract This study evaluated the biological traits and life table parameters of the predatory mite Neoseiulus californicus (McGregor) when fed on four prey species: the clover mite (Bryobia praetiosa Koch), the citrus brown mite (Eutetranychus orientalis Klein), the two-spotted spider mite (Tetranychus urticae Koch), and the acarid mite Tyrophagus putrescentiae (Schrank). Laboratory conditions were maintained at 27 ± 1 °C and 70 ± 5% relative humidity (RH). All prey types were suitable as food for N. californicus, but prey diet significantly influenced the predator's immature development and adult longevity in both sexes. The shortest developmental time (egg to adult) of predatory mite was 4.35 and 4.17 days for male and female when fed on Te. urticae motile stages. The shortest and longest oviposition periods were 12.53 and 19.07 days for B. praetiosa and Te. urticae, respectively. The highest fecundity per female was 39.60 eggs for Te. urticae, followed by 31.67 eggs for E. orientalis. The study found that Te. urticae had the highest net reproductive rates (R₀), intrinsic rate of increase (r), finite rate of increase (λ), and gross reproduction rate (GRR). Additionally, Te. urticae exhibited the shortest mean generation time (T) and doubling time (DT) compared to B. praetiosa and Ty. putrescentiae. Age-stage-specific fecundity (fxj) was highest for Te. urticae, followed by E. orientalis, Ty. putrescentiae, and B. praetiosa. A similar trend was observed in the age-stage-specific life expectancy (exj). Interestingly, the highest predation rates for both male and female N. californicus were observed when feeding on Ty. putrescentiae compared to the other prey species. The results obtained can be useful in the biological control of phytophagous mites on field crops. Further studies are needed to evaluate its effectiveness in combination with other parameters of a control program for managing pests affecting crops under field or greenhouse conditions.

Abstract The two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) is a significant pest of strawberries, both in greenhouse and field conditions. Research was conducted to evaluate the impact of seven different strawberry cultivars (Albion, Gaviota, Camarosa, Paros, Ventana, Sabrina, and Selva) on the life history of TSSM under laboratory conditions at 25 ± 1 ℃, 65 ± 5% RH, and a photoperiod of 16:8 (L:D). The results showed that the pre-adult duration varied significantly from 8.95 to 9.92 days, where Albion and Gaviota had the longest (9.69 and 9.92 days, respectively), while Ventana had the shortest duration (8.59 days). Female longevity was longer on Albion compared to other cultivars, but there was no significant difference among the other cultivars tested. The highest fecundity was observed on Sabrina and Gaviota (113 and 108 eggs/female, respectively), while the lowest was recorded on Paros (67.97 eggs/female). TSSM had the highest intrinsic rate of increase (r) and finite rate of increase (λ) (0.265 d⁻¹ and 1.304 d⁻¹, respectively) on Sabrina, while on Albion had the lowest ones (0.230 d⁻¹ and 1.259 d⁻¹, respectively). The results indicated that TSSM preferred Sabrina, while Albion was less favorable for this phytophagous mite. This information can be useful for designing an integrated pest management programs to control the TSSM population.

Abstract Learning and early-life experiences are crucial in enhancing predatory behavior and resource utilization among predators, increasing their ability to adapt to fluctuating environmental conditions. Foraging predators exposed to food-related stress often develop compensatory behaviors that support their survival and reproductive success in resource-scarce environments. This study examines the effects of food stress during nymphal and adult stages on the predation behavior and fecundity of two predatory mites, Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) feeding on two-spotted spider mite Tetranychus urticae Koch. In the first experiment, mites experienced food stress during the nymphal stage, resulting in significantly higher predation rates but lower egg production in adulthood compared to controls. In the second experiment, mites faced 24 hours of food stress only in adulthood, leading to increased predation and reduced egg production compared to controls. In the third experiment, N. californicus reared solely on pollen from egg to adulthood exhibited enhanced predation and decreased egg production as adults. These findings highlight the adaptive potential of food-stress-induced compensatory behaviors, including enhanced predation efficiency and reduced fecundity, which act as survival strategies under resource constraints. The study underscores the role of mechanisms such as learning and energy optimization in facilitating these responses. Moreover, these adaptive behaviors present valuable opportunities for Integrated Pest Management (IPM) programs by enhancing the performance of biological control agents under variable environmental conditions.

Abstract Drought is causing Algerian palm groves to suffer an increase in date palm acariasis, which is caused by the mite Oligonychus afrasiaticus (McGregor, 1939). This mite feeds on the fruit's epidermal cell, giving it a rough appearance and making it unfit for consumption. The study was carried out in the Souf region, north of the Grand Erg Oriental in Algeria over 12 months from July 2020 to June 2021. Our study aimed to determine the infestation of the date dust mite O. afrasiaticus, and to understand the population dynamics of this mite and its predator Stethorus punctillum (Weise, 1891) in the Deglet Nour and Ghars varieties, within different types of palm groves (El Bayadha 33° 19' 40'' N, 6° 55' 33'' E, Oued Alanda 33° 17' 25'' N, 6° 46' 39'' E and Sandarous 33° 13' 18'' N, 6° 58' 40'' E). Two sampling methods were used, direct collection of dates using the date branch sampling method and the date palm branch striking method. The result showed that the beginning of O. afrasiaticus infestation of dates coincided with the green phenological stage of dates (Kimri) and ended with the beginning of the Bser stage (Khalal). Our results showed that the Ghout palm grove was the least affected by this pest compared with the other groves. Dates of the Deglet Nour variety have the highest infestation rates compared with the Ghars variety. We also observed that the ladybird, S. punctillum, acts as a key predator of the date palm spider mite highlighting a significant trophic interaction between the two species. Our results showed that the population dynamics of these acarophagous insects vary according to the degree of presence of their trophic preferences and the ecological factors of the biotope.

Abstract Phytoseiid mites play a crucial role in biological control programs. Developing efficient mass-rearing techniques for these mites is essential to enhance their applicability in large-scale management programs. This study aimed to develop and validate a simple mass-rearing protocol for the continuous production of generalist phytoseiid mites (Amblyseius swirskii, Neoseiulus californicus, and Neoseiulus barkeri). The rearing system consisted of a Petri dish placed on a water-saturated sponge in a plastic box containing water. Mites were fed a mixture of cattail pollen, rice husk, and Tyrophagus putrecentiae mites which were introduced into the rearing units three times a week. The prey mite was maintained in a similar system using yeast granules and rice husk as food. Population growth of the predatory mites was observed over an 8-week period under controlled laboratory conditions (25 ± 1 °C, 65 ± 5% RH, and 16L:8D photoperiod). The results showed that all three species successfully grew and overpopulated in the 6^th week, with 380.2 ± 16.7, 211.4 ± 12.9, and 283.9 ± 18.6 adult females of A. swirskii, N. californicus, and N. barkeri, respectively, being produced. These values represent increases of 38, 21.1, and 28.3 times their respective initial population densities. A gradual decline in the phytoseiids population was observed in each unit following the sixth week. This suggests that the sixth week serves as a suitable time frame for subdividing the rearing units to maintain optimal population levels. The proposed rearing protocol turned out to be useful for the continuous production of the three test species, providing optimal conditions for population growth while preventing mites from escaping the box. This protocol offers a practical solution for the commercial mass production of generalist phytoseiids.

Abstract New species of oribatid mites of the family Galumnidae—Dimidiogalumna abaiensis sp. nov. and Galumna (Galumna) gamozonensis sp. nov.—are described from forest litter in the Gamo Zone, southern Ethiopia. Dimidiogalumna abaiensis differs from the related species D. grandjeani by the pteromorph pattern, the presence of the dorsosejugal suture, the form of the notogastral porose area Aa, the epimeral formula, and the length of the rostral and lamellar setae. Galumna (Galumna) gamozonensis differs from the related species G. (G.) grandjeani by the body size, the morphology of the rostrum, bothridial seta and notogastral porose area Aa, the presence of the dorsosejugal suture and a median pore, and the prodorsum and pteromorph pattern; G. (G.) gamozonensis differs from the related species G. (G.) korupensis by the morphology of the bothridial seta and notogastral porose areas Aa and A3, the presence of a median pore, and the prodorsum, pteromorph and genital plate pattern.

Abstract A new genus and species, Maculanemus chilensis gen. nov., sp. nov. (Acari: Tarsonemidae: Tarsoneminae) and a new species Steneotarsonemus (Neosteneotarsonemus) patagoniensis sp. nov. are described based on females collected in mosses in Chilean Patagonia. The genus Steneotarsonemus is recorded in Chile for the first time. The taxonomic position of the genus Maculanemus gen. nov. and unusual character states of new species are discussed.

Abstract Machadobelba (Oribatida, Machadobelbidae) currently comprises 18 species collectively distributed in the Afrotropical, Neotropical, and Oriental regions. We describe a new species—M. bimorpha sp. nov.—based on adults collected from forest litter in Malaysia. The new species is characterized by the morphology of the rostral (short, phylliform, shortly ciliated distally in males versus medium-sized, setiform, sparsely barbed in females), bothridial (bifurcate), and notogastral (dilated mediodistally) setae, the presence of two anoadanal porose areas in males (versus absent in females), two long, longitudinal ridges in anterior part of the prodorsum, and the length of the costula (shorter than half of prodorsum).

Abstract We describe two new species of oribatid mites (Oribatida) based on adult males—Gymnobodes schedeli sp. nov. (Carabodidae) collected from rotten wood and humus under a tree in Zambia and Galumna (Galumna) luisi sp. nov. (Galumnidae) collected from detritus among Cyperus papyrus in Uganda. Gymnobodes schedeli sp. nov. differs from all species of the genus by the presence of a depression in the basal part of the prodorsum, and by the notogastral ornamentation/sculpturing. Galumna (Galumna) luisi sp. nov. differs from G. (G.) incisa by the body size, the morphology of the rostrum and notogastral porose areas Aa and A3, the presence of a rostral bulge and a long longitudinal fold having short lateral branches in the anteromedial part of the notogaster, the absence of a median pore, and the location of the notogastral lyrifissure im and leg famulus.

Abstract Uzbekistan hosts a diverse tick fauna comprising 30 species from the families Ixodidae and Argasidae. While tick morphology is generally well-documented, rare anomalies such as ectromely have been observed in natural populations. This study reports an abnormal malformation in a tick collected from a camel in Uzbekistan. One morphologically anomalous tick was collected from a camel in Navoiy, Uzbekistan, and submitted for morphological identification. The specimen was identified as an adult female Dermacentor niveus, displaying a morphological anomaly characterized by ectromely. This case highlights a rare occurrence of ectromely in D. niveus and underscores the need for larger studies to assess the prevalence of such anomalies and their potential role in pathogen transmission. Understanding these abnormalities could enhance tick surveillance and contribute to public health strategies. To our knowledge, this is the first report of an anomaly in D. niveus .

Abstract A tribute to an outstanding pioneer acarologist of Iran, Prof. Dr. Hossein Sepasgosarian.