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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]

Rhizoctonia solani and Fusarium solani were found to have an association with damping-off and complex wilt and root rot symptoms of tomato seedling plants gathered from various greenhouses in Qassim region, Saudi Arabia. The acquired isolates were found virulent enough to attack tomato plants (cv. Tres Cantos) causing complex wilt/rot diseases as well as pre and post emergence of damping-off diseases. These isolates present more virulence in the pathogenicity tests. Huwa-San TR50, a hydrogen peroxide solution that has been stabilized by adding a small amount of silver and has been used extensively as a germicide. Biocide agent Huwa-San TR50 (hydrogen peroxide with 3% silver), was examined for biological control of root wilt/rot and damping-off as well as growth augmentation of tomato plants in vitro and in vivo. The hostile biocide agent hampered growth of the tested morbific fungi and recorded highest inhibited growth in vitro. Under growth chamber condition, all treatments notably decreased root rot/wilt and damping-off intensity and resulted into an increase in the number of surviving plants. Moreover, under growth chamber conditions, these remedies caused an increase in growth parameters (height of plants, and weights when fresh and dry) of the surviving plants which were kept in pots rather than in control conditions. Tomato soil drenching with Huwa-San TR50 in concentration 12000, 14000 and 16000 ppm achieved the ideal results for combating root wilt/rot and damping-off diseases, as well as the highest growth parameters were recorded in growth chamber conditions with the addition of enhanced plant growth and higher yield constituents. [ABSTRACT FROM AUTHOR]

Tuta absoluta Meyrick (pinworm), is a seriously crucial leaf mining, stalk borers and fruit damaging pest of solanaceae plants. Among solanaceous plants, tomato is considered to be the most preferred host to T. absoluta. Infestations caused by pinworm lead to reduction in tomato yield and its worldwide export. The current study has been conducted to evaluate effectiveness of two entomopathogenic fungi; Beauveria bassiana and Metarhizium anisopliae against eggs of T. absoluta under laboratory conditions. The potential of the two fungi was also assessed as an instrument of integrated pest management system through biological control. Eggs of T. absoluta were treated with four different conidial concentrations of each entomopathogenic fungus. These fungi were evaluated for their toxicity at four different conidial concentrations (4x105, 6x105, 8x105 and 1.0x106 conidia/mL). Twenty-one days post treatment, spore concentration 1.0x106 conidia/mL, resulted in the highest death rate: 50 and 37.6% with eggs when treated by B. bassania and M. anisopliae, respectively. The lowest mortality 33.6 and 25.6% of eggs was observed when T. absoluta eggs were treated with 4x105 conidia/mL of B. bassania and M. anisopliae, respectively. Mortality values resulted from the experiments indicated that B. bassania showed superiority over M. anisopliae regarding its effect on controlling of T. absoluta eggs. In addition, 4x105 conidia/mL showed the minimum mortality effect among the two fungi used in the bioassay. Mortality and spore production on the eggs were significantly higher with the higher spore concentrations (8x105 conidia/mL) of M. anisopliae and B. bassiana. Our findings suggest that the moderate (8x105 conidia/mL) and the higher (10x105 conidia/mL) spore concentration/ml of B. bassania and M. anisopliae are potent entomopathogenic and have the potential to be developed as effective and potent bio-control agents hostile to T. absoluta eggs in IPM programs. [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]

Injudicious application of insecticides can cause a sharp reduction in the population of several predatory insects and mites including parasitoids. The current study was designed to investigate the effect of four insecticides (i.e. bifenthrin, cypermethrin, deltamethrin and acetamiprid) against the natural population of hymenopterous parasitoids parasitizing various pests of Alfalfa. When used against the pests of Alfalfa, these insecticides also affected the natural population of hymenopterous parasitoids significantly, resulting into ecological imbalance and making the crop more susceptible to pest infestation. This study has proved that bifenthrin, cypermethrin, deltamethrin and acetamiprid can cause a sharp decline of the population of twelve different hymenopterous parasitoids families of (trichogrammatidae, mymaridae, aphelinidae, encytidae, eulophidae, pteromalidae, eupelmidae, ichneumonidae, braconidae, proctotrupidae, platygastridae and scelionidae) with a detectable variation in their resistance to these insecticides. The comparison of means of survival percentage for different insecticides revealed that cypermenthrin caused the lowest mortality (highest survival percentage) to parasitoids followed by deltamenthrin, acetamiprid and bifenthrin to cause maximum mortality respectively (lowest survival percentage) to hymenopterous parasitoids. This would add further environmental concern to the natural population of several predatory insects as their viability will be significantly affected in different contaminative areas. Thus, such studies are also required to investigate the effects of other insecticides which have been extensively used for pest control. [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]

The tomato borer or the tomato leafminer (TLM), Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) has invaded the Mediterranean basin recently from South America and it is becoming a major global pest of tomato. Additionally, the Egyptian cotton leafworm (ECLW), Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) is also a serious pest of various economic and non-economic crops in other Mediterranean countries. The excessive use of chemical pesticides is dangerous because these insect pests can develop resistance. The purpose of the present study was to evaluate the efficacy of emamectin-benzoate insecticide against two lepidopterous insects namely; T. absoluta and S. littoralis under laboratory conditions. Laboratory results showed that emamectin-benzoate was effective against larval stages of insects under laboratory conditions. All four concentrations of emamectin-benzoate caused a significant percentage of mortality after 24 hours of treatment as the percentage of mortality increased gradually with time. But almost all concentrations caused 100% mortality of larvae in both species on the 4th and 5th day of treatment. The obtained results showed that there were significant differences between insecticide concentrations, time of exposure and mortality percentage without any adverse effect on the tomato plants. [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]

Silver Nanoparticles (AgNP) have become one of the most promising approaches for pest control in recent years. The present study aimed to evaluate the effects of silver nanoparticles on all stages of eriophyid mite, the tomato russet mite, Aculops lycopersici (Massee) (Acari: Eriophyidae) and tetranychid mite, the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). This includes its impacts on phytoseiid predators, Euseius scutalis (Athias-Henriot) and Neosiulus cucumeris Oudemans (Acari: Phytoseiidae), on tomato plants under greenhouse conditions. Four different concentrations of silver nanoparticles (53.94, 107.88, 161.82 and 215.76ppm) as well as the control (well water) were examined. The obtained results indicated that the mortality percentage of both phytophagous and predatory mites were associated with an increase of the concentrations of silver nanoparticles. Silver nanoparticles were found to be significantly effective in killing A. lycopersici and T. urticae with minimal effects on E. scutalis and N. cucumeris. The mortality percentage was 20.88, 45.34, 72.80 and 93.37% for A. lycopersici and 18.99, 42.69, 73.21 and 85.21% for T. urticae while the mortality percentage was 2.39, 8.66, 17.48 and 23.77% for E. scutalis and 4.43, 12.71, 14.42 and 19.95% for N. cucumeris one week after exposure to 53.94, 107.88, 161.82 and 215.76ppm of silver nanoparticles, respectively. Moreover, the findings showed that silver nanoparticles caused a reduction in the percentage of eggs hatching. The percentages of larvae hatching from eggs were 68.11, 49.73, 34.55 and 20.36% for A. lycopersici and 79.20, 64.36, 43.30 and 30.29% for T. urticae one week after exposure to silver nanoparticles at 53.94, 107.88, 161.82 and 215.76ppm, respectively, compared with the control (well water). This research proved that the implementation of silver nanoparticles at low dosages could reduce the population of phytophagous mites associated with tomato plants, with low detrimental effects on non-target mites. [ABSTRACT FROM AUTHOR]

The oriental spider mite is the common name of Eutetranychus orientalis (Klien). The efficacy of Huwa-San TR50, abamectin and bifenthrin for the control of the oriental spider mite was evaluated under field and laboratory conditions. Seven concentrations of Huwa-San TR50 (500, 1000, 2000, 3000, 4000, 5000 and 6000ppm) and the recommended dose (RD) of abamectin and bifenthrin including a control (well water) were applied in the field and laboratory. E. orientalis were susceptible to certain concentrations of Huwa-San TR50 and the RD of abamectin and bifenthrin. All these substances produced a significant reduction on the adults' mortality of E. orientalis. Nevertheless, the compared efficacy showed differences as Huwa- San TR50 was found to significantly kill E. orientalis and can also cause a failure in the eggs hatching of E. orientalis under field and laboratory conditions. In addition, it caused a dose dependent on the population and number of larvae hatching form eggs of E. orientalis. In contrast, abamectin and bifenthrin can only cause a significant reduction on the population of E. orientalis whereas Huwa-San TR50 can cause a reduction on both the population and number of larvae hatching form eggs of E. orientalis, as Huwa-San TR50 can reduce the number of larvae hatching from eggs of by ~2-fold of the reduction gained with the application of the RD of abamectin and bifenthrin. The application of Huwa-San TR50 would be considered as a promising method for controlling E. orientalis as it is environmentally friendly chemical compound compared with other acaricides such as abamectin and bifenthrin. [ABSTRACT FROM AUTHOR]