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Miticidal action of hexythiazox has been investigated against three mites, Citrus Rust Mite, Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae), False Spider Mite, Brevipalpus californicus (Banks) (Acari: Tenuipalpidae) and Citrus Brown Mite, Eutetranychus orientalis Klein (Acari: Tetranychidae), infesting citrus trees in the region of Al Qassim, Saudi Arabia. Three concentrations of hexythiazox, half of the recommended dose (HRD), the recommended dose (RD) and double recommended dose (DRD) were used against the selected mite species at immature and adult stages. Mortality data was recorded after regular intervals of a day till seven days of post-treatment application. Larvicidal action of the pesticide was observed in terms of post spray percentage of egg hatching. Trails regarding mortality of immature and adult mites were carried out under laboratory and field conditions. A maximum of 72.88% and 64.41% mortality was observed in immature mites of P. oleivora at RD under laboratory and field conditions respectively. The highest mortality of adult mites at RD was recorded again in P. oleivora that was 18.97 and 20.39% under laboratory and field conditions respectively, showing that mortality percentage was insignificant in adults. Under the same conditions, mortality of mites observed at HRD was non-significant and there was negligible increase in mortality when concentration was increased from RD to DRD. Success of hatching for the treated eggs of the three selected mites was observed in the range of 5.00 to 12.50% at the recommended dose. This indicated that hexythiazox has the significant potential of inhibiting hatching process. For the successful control over citrus mites, the appropriate time of spray is prehatching stage. [ABSTRACT FROM AUTHOR]

The toxicity of glyphosate and metribuzin on five species of soil-dwelling predatory mites, Lasioseius dentatus (Fox) (Acari: Ascidae), Androlaelaps casalis (Berlese) (Acari: Laelapidae), Rhodacarus roseus (Oudemans) (Acari: Rhodacaridae), Macrocheles muscaedomesticae (Scopoli) (Acari: Macrochelidae) and Cunaxa setirostris (Hermann) (Acari: Cunaxidae) was evaluated under laboratory conditions. Three different concentrations (half of the recommended dose (HRD), recommended dose (RD) and double the recommended dose (DRD)) of both herbicides were tested. All soil-dwelling predatory mites under study showed high susceptibility to both herbicides, demonstrating that they can significantly reduce the population of all five species of soil-dwelling predatory mites. HRD of glyphosate can reduce the population of all five species of soil-dwelling predatory mites by > 50%, except C. setirostris, as its mortality was 30%, whereas HRD of metribuzin can only reduce the population of L. dentatus and M. muscaedomesticae by > 50%. Obviously, glyphosate seems to be more toxic to all five species of soil-dwelling predatory mites than metribuzin. L. dentatus was found to be the most sensitive soil-dwelling predatory mite, whereas C. setirostris was found to be the least sensitive to both herbicides, as well as a control (well water), compared with all the tested soil-dwelling predatory mites. Finally, the highest mortality rates (100%) were obtained for DRD of both herbicides. Therefore, extra care and serious caution must be exercised when diluting and applying these herbicides to ensure their RD is never exceeded as they can kill all soil-dwelling predatory mites studied here in significant numbers, which leads to a sharp reduction in their populations as well as a reduction in their role in the ecological balance. [ABSTRACT FROM AUTHOR]

Olive is a blessed and therapeutic fruit cultivated all around the globe in relatively temperate and dry regions. Keeping in view the quality and yield of the crop, use of pesticides is indispensable. Traditional pesticides used against crop enemies are effective but unsafe to environment, humans and predators. Olive fields of Saudi Arabia are the biggest in the world and facing infestation due to rapidly increasing number of diverse mite species. Recently, four mite species, Tegelophus hassani, Aceria olive, Oxycenus niloticus and Tetranychus urticae found to be causing severe damage to the plants, have been identified in the olive fields of Saudi Arabia. Huwa-San TR50 is a well-known water disinfectant and considered to be safe as its adverse effects on plants have not been reported as yet. The present study has been conducted to evaluate the use of Huwa-San TR50 as an acricide against four olive mites and two of their predators under laboratory and field conditions. Five different concentrations of Huwa-San TR50; 1000, 2000, 3000, 4000 and 5000 ppm were used based on previous studies to observe mortality of the selected phytophagous mites namely T. hassani, A. olive, O. niloticus and T. urticae. Gradual increase in mortality was observed when mites were treated with Huwa-San TR50 in the concentration range of 1000 - 5000 ppm. Optimum concentration of Huwa-San TR50 to be used against the mites was found to be 4000 ppm as there was negligible increase in mortality beyond this concentration. T. urticae was relatively resistant to Huwa-San TR50 with mortality of 76.58% at optimal concentration. Huwa-San TR50 has effectively impacted egg hatching especially in case of O. niloticus, where successful hatching was only 20%. Eggs of T. urticae are relatively resistant showing 57.97% hatching. The same trend and similar results of mortality and egg hatching were obtained under laboratory and field trials. As an essential part of this research, effect of Huwa-San TR50 was also observed on two predatory mites namely; Phytoseius plumifer and Agistemus exertus and it was found to be relatively safe to predatory mites showing mortality of 30 to 34% at optimum concentration. Again there was insignificant difference in mortality and egg hatching under field and laboratory conditions. Huwa-San TR50 being ecofriendly, safe to predatory mites and an effective acaricide against olive mites and their eggs is recommended for its commercial use in olive orchards. [ABSTRACT FROM AUTHOR]

Traditional acaricides, when used in agricultural fields and green houses, kill predatory mites along with phytophagous mites and cause disturbance in the natural biological control system. The present study involves a novel strategy in pest control systems that is through parallel control on hatching along with killing mites while being at the same time relatively safe to predatory mites. The efficacy of Huwa -San TR50 on the mortality of grape erineum mites, Colomerus vitis, and their egg hatching in comparison to traditional acaricides has been evaluated. Abamectin and bifenthrin cause 83.82 and 98.11% mortality of predatory mites, respectively, when treated with recommended doses. The efficiency of these two acaricides is relatively lower against phytophagous mites, as the highest mortality is 84.46% with bifenthrin and 76.00% with abamectin. It is also observed that abamectin and bifenthrin affect the hatching process negligibly for the eggs of both Colomerus vitis (Pagenstecher) (Acari: Eriophyidae) and Tenuipalpus granati (Sayed) (Acari: Tenuipalpidae). Mortality of C. vitis and T. granati caused by Huwa -San TR50 is 89.86 and 81.76%, respectively, at a spray concentration of 4000ppm. The application of Huwa-San TR50 on eggs of the two phytophagous mites severely affected hatching and only 33.92% successfully hatched. This laboratory study suggests that Huwa -San TR50 can be a better replacement for chemical acaricides. Further, to protect the natural control system through predatory mites, Huwa -San TR50 should be applied as it causes significant mortality in C. vitis and T. granati and is insignificantly harmful to predatory mites. [ABSTRACT FROM AUTHOR]

The predatory phytoseiid mite, Phytoseius plumifer (Canestrini & Fanzago) (Acari: Phytoseiidae), has shown promising traits for biological control of four mite species, Aceria olivi, Oxycenus niloticus, Tegolophus hassani (Acari: Eriophyidae) and Tetranychus urticae (Acari: Tetranychidae), the major pests of olive trees in Saudi Arabia. In the present study, reproduction and population growth parameters of P. plumifer on moving stages of four mite species were studied in the laboratory at 35±1°C, 55±5% RH and a photoperiod of 12: 12 (L: D) hours. The predatory mite, P. plumifer demonstrated that it is capable of developing successfully from egg to adult stage throughout its entire life history consuming only four preys. The total immature developmental time was 5.67, 5.87, 5.92 and 5.77 days for females and 5.18, 5.32, 5.49 and 5.50 days for males when the predator consumed A. olivi, O. niloticus, T. hassani and T. urticae, respectively. The sex ratio of P. plumifer was 0.73, 0.70, 0.70 and 0.60 (females/females + males). Mated females laid on average 2.83, 2.70, 2.38 and 1.72 eggs per day and 57.46, 50.80, 50.02 and 33.95 eggs during their mean ovipositional period of 20.25,18.77, 20.95 and 20.88 days, respectively. The net reproductive rate (R0) was 37.65, 35.18, 33.59 and 26.38 females/female/generation, the intrinsic rate of increase (rm) was 0.298, 0.288, 0.277 and 0.179 females/female/day, the finite rate of increase (λ) was 1.937, 1.861, 1.785 and 1.212 population multiplication/day, and the mean generation time (T) was 14.25, 15.78, 15.22 and 16.56 days when a predator consumed A. olivi, O. niloticus, T. hassani and T. urticae, respectively. The adult predatory female consumed an average of 110.66 A. olivi, 103.71 O. niloticus, 99.75 T. hassani and 14.35 T. urticae/day. These findings imply that the four mites, especially A. olivi, proved to be acceptable nourishment for P. plumifer, as a facultative predator, where P. plumifer does well and is widely and successfully used for biocontrol of A. olivi, O. niloticus, T. hassani and T. urticae associated with olive trees. [ABSTRACT FROM AUTHOR]

Extensive use of pesticides in public health and agricultural programs has caused many environmental problems as well as toxic effects on non-target organisms including predatory mites. This study has been conducted to determine toxic effects of two acaricides; oxamyl and pyridaben at their three different concentrations. Effect of spray was observed on eggs, immatures and adults of seven predatory mites; Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), Amblyseius cydnodactylon (Shehata and Zaherand), Phytoseius plumifer (Canestrini and Fanzago), Typhlodromips swirskii (Athias-Henriot), Euseius scutalis (Athias-Henriot), Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae) and Agistemus exsertus (Gonzalez) (Acari: Stigmaeidae) under laboratory conditions. Immature stage of these predatory mites was found to be more susceptible than adults to both oxamyl and pyridaben. The latter was found to be more toxic to immatures and adults than oxamyl. Effect of both pesticides on hatching was found to be insignificant because more than 50% of their eggs were successfully hatched even at the DRD. This study has shown that oxamyl and pyridaben can disrupt biological control due to their toxicity to predatory mites, so extra care must be taken with over application of these acaricides. [ABSTRACT FROM AUTHOR]

Side effects of oxamyl and hymexazol on five species of soil-dwelling predatory mites, Lasioseius dentatus (Fox) (Acari: Ascidae), Androlaelaps casalis (Berlese) (Acari: Laelapidae), Rhodacarus roseus (Oudemans) (Acari: Rhodacaridae), Macrocheles muscaedomesticae (Scopoli) (Acari: Macrochelidae) and Cunaxa setirostris (Hermann) (Acari: Cunaxidae) were tested under stringent laboratory conditions. Both oxamyl and hymexazol were found to drastically kill all five predatory soil mites listed above at three different concentrations (half of the recommended dose (HRD), recommended dose (RD) and double the recommended dose (DRD). Oxamyl was found to be more toxic than hymexazol to all five predatory soil mites as it could reduce their population by > 40% at the HRD, except R. roseus, as its population was reduced to 27.80%. In addition, the application of oxamyl can decrease the population of five predatory soil mites by >83% at RD while at DRD a total mortality rate could be seen. In conclusion, this research study has provided evidence which highlights the reduction of population of five predatory soil mites even after the exposure to half of the recommended dose of oxamyl and hymexazol. Therefore, precautionary measures should be taken to maintain the sustainability and to avoid disturbing the natural balance of the ecosystem. [ABSTRACT FROM AUTHOR]