19 research outputs found
Biological Control of Tetranychidae by Considering the Effect of Insecticides
Spider mites (family Tetranychidae) are important pests of many agricultural, medicinal and ornamental plants worldwide. They possess needle-like chelicerae which pierce plant cells, often feeding on chloroplasts on the under surface of the leaf and cause upper leaf surfaces develop whitish or yellowish stippling. Additionally spider mites produce silk webbing which covers the leaves. In this chapter we present common control methods of these mites including biological control with emphasizing on the prey preference, switching behavior and mutual interference of a biological control agent, Phytoseius plumifer (Canestrini and Fanzago). Additionally the side effects of two acaricides, abamectin and fenpyroxymate, on this predator will be discussed
Figure 1 in Alfalfa responses to drought, salinity, and herbivory by Tetranychus urticae (Acari: Tetranychidae) and performance of the pest on water-stressed plants
Figure 1. Effects of drought stress on proline content of alfalfa plants before and after Tetranychus urticae feeding. Within each column mean (± SE) followed by the same letter(s) are not significantly different. Capital letters show the effect of drought.Published as part of Khodayari, Samira & Abedini, Fatemeh, 2022, Alfalfa responses to drought, salinity, and herbivory by Tetranychus urticae (Acari: Tetranychidae) and performance of the pest on water-stressed plants, pp. 695-711 in Persian Journal of Acarology 11 (4) on page 701, DOI: 10.22073/pja.v11i4.75896, http://zenodo.org/record/744746
Figure 2 in Alfalfa responses to drought, salinity, and herbivory by Tetranychus urticae (Acari: Tetranychidae) and performance of the pest on water-stressed plants
Figure 2. Effects of salinity stress on proline content of alfalfa plants before and after Tetranychus urticae feeding. Within each column mean (± SE) followed by the same letter(s) are not significantly different. Capital letters show the effect of salinity.Published as part of Khodayari, Samira & Abedini, Fatemeh, 2022, Alfalfa responses to drought, salinity, and herbivory by Tetranychus urticae (Acari: Tetranychidae) and performance of the pest on water-stressed plants, pp. 695-711 in Persian Journal of Acarology 11 (4) on page 702, DOI: 10.22073/pja.v11i4.75896, http://zenodo.org/record/744746
The responses of cucumber plants subjected to different salinity or fertilizer concentrations and reproductive success of Tetranychus urticae mites on these plants
International audienceThe plant stress hypothesis posits that a herbivore's reproductive success increases when it feeds on stressed plants, while the plant vigor hypothesis predicts that a herbivore preferentially feeds on more vigorous plants. We examined these opposing hypotheses by growing spider mites (Tetranychus urticae) on the leaves of stressed and healthy (vigorous) cucumber plants. Host plants were grown under controlled conditions at low, moderate, and high concentrations of NaCl (to induce salinity stress), at low, moderate, and high fertilizer concentrations (to support growth), and without these additions (control). The effects of these treatments were evaluated by measuring fresh and dry plant biomass, carotenoid and chlorophyll content, antioxidant enzyme activity, and concentrations of PO, K, and Na in plant tissues. The addition of low concentrations of fertilizer increased dry mass, protein, and carotenoid content relative to controls, suggesting a beneficial effect on plants. The highest NaCl treatment (2560 mg L) resulted in increased Na and protein content relative to control plants, as well as reduced PO, K, and chlorophyll levels and reduced catalase and ascorbate peroxidase enzyme activity levels. Analysis of life table data of T. urticae mites raised on leaves from the aforementioned plant groups showed the intrinsic rate of increase (r) for mites was 0.167 day in control specimens, 0.125 day for mites reared on plants treated with a moderate concentration of fertilizer (10 mL L), and was highest (0.241 day) on plants grown under moderate salinity conditions (1920 mg L NaCl). Reproductive success of T. urticae did not differ on plants watered with a moderate concentration of NaCl or a high concentration of fertilizer. The moderately-stressed plants formed a favorable environment for the development and reproduction of spider mites, supporting the plant stress hypothesis
Healthcare provision for medical tourism: A comparative review
Providing quality services, using modern technologies, having effective marketing, and providing services at an international level have led to the globalization of hospital services. This study aimed to identify the components of health services in developing countries that provide services to international patients. A comparative review was conducted by searching in PubMed, Scopus, Web of Science, Google Scholar, Google, and the websites of the World Medical Tourism Organization, the World Bank, and the Ministry of Health of the selected countries from 2000 to 2022. Iran, Turkey, Jordan, Costa Rica, the UAE, and Singapore were selected. The data were collected and analyzed using a comparative table. Different strategies were used to develop the medical tourism industry among the studied countries, but the main challenges in this field included the inappropriateness of the quality of the services provided or the provision of services that did not meet the needs of patients, the lack of expert human resource, not using medical facilitation companies, communication problems with patients, insufficient government support for medical tourism, and strict laws regarding business. The development of activities in the medical tourism industry requires planning in various dimensions. It seems that developing the medical marketing and activities of facilitator companies to facilitate patient admission, monitoring the quality of services provided, improving interdepartmental coordination, and considering a single trustee for this industry will improve the medical tourism status in Iran
Seasonal changes in the cold hardiness of the two-spotted spider mite females (Acari: Tetranychidae).
International audienceThe twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is an important agricultural pest. Population dynamics and pest outbreaks highly depend on the overwintering success of the mite specimens; therefore, it is necessary to assess winter survival dynamics of this pest. Seasonal changes in supercooling point (SCP) and acute cold tolerance (2-h exposure at -5, -10, -15, -20, -23, or -25°C) were assessed in field-collected females during the winter in 2010-2011 in Iran. The SCP values varied from a minimum of -30.5°C (January 2011) to a maximum of -12.6°C (April 2011). Significant differences were recorded in the SCP distribution patterns between autumn- and winter-sampled females, depicting the acquisition of cold hardiness over the winter. The mean ambient air temperature was the lowest in January (4°C), when the females showed the highest supercooling ability. Correlated patterns between monthly temperatures and acute cold tolerance also were found. At -20°C, the survival of the mites was very low (10%) when they were sampled in October 2010; whereas it was high (97.5%) in January 2011, before decreasing to 5% in April 2011. The present data show that T. urticae females are chill tolerant and capable of adjusting their cold tolerance over the winter season. Acute cold tolerance (-15 and -20°C) and SCP represent valuable metrics that can be used for predicting the seasonal changes of the cold hardiness of T. urticae females
Deciphering the Metabolic Changes Associated with Diapause Syndrome and Cold Acclimation in the Two- Spotted Spider Mite Tetranychus urticae
Diapause is a common feature in several arthropod species that are subject to unfavorable growing seasons. The range of environmental cues that trigger the onset and termination of diapause, in addition to associated hormonal, biochemical, and molecular changes, have been studied extensively in recent years; however, such information is only available for a few insect species. Diapause and cold hardening usually occur together in overwintering arthropods, and can be characterized by recording changes to the wealth of molecules present in the tissue, hemolymph, or whole body of organisms. Recent technological advances, such as high throughput screening and quantification of metabolites via chromatographic analyses, are able to identify such molecules. In the present work, we examined the survival ability of diapausing and nondiapausing females of the two-spotted spider mite, Tetranychus urticae, in the presence (0 or 5uC) or absence of cold acclimation. Furthermore, we examined the metabolic fingerprints of these specimens via gas chromatography-mass spectrophotometry (GC-MS). Partial Least Square Discriminant Analysis (PLS-DA) of metabolites revealed that major metabolic variations were related to diapause, indicating in a clear cut-off between diapausing and non-diapausing females, regardless of acclimation state. Signs of metabolic depression were evident in diapausing females, with most amino acids and TCA cycle intermediates being significantly reduced. Out of the 40 accurately quantified metabolites, seven metabolites remained elevated or were accumulated in diapausing mites, i.e. cadaverine, gluconolactone, glucose, inositol, maltose