• Korean journal of applied entomology
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• v.43 no.1
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• pp.71-79
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• 2004

Toxicities of 42 pesticides (13 acaricides, 13 insecticides, 13 fungicides and 3 adjuvants) commonly used to control rose insect, mite, and disease pests were evaluated to the two-spotted spider mite, Tetranychus urticae egg and adult, and its predator Phytoseiulus persimilis egg, nymph and adult at the recommended concentration. The effect of density suppression of T urticae by predatory mite and pesticide mixture on the rose in the greenhouses was also investigated. Among 13 acaricides tested, acequinocyl, bifenazate, fenbutatin oxide and spirodiclofen showed much less toxicity to P. persimilis than to T urticae. Among insecticides, acetamiprid, imidacloprid, spinosad, thiamethoxam and acetamiprid＋etofenprox showed low toxicity to P. persimilis. and T ruticae. Among 13 fungicides, azoxystrobin, kresoxim-methyl, myclobutanil, nuarimol, triadimefon, triflumizole and oxadixyl＋mancozeb had a negligible effect on P. persimilis and T. urticae. Among three adjuvants, cover and siloxane expressed high toxicity, while spreader showed very low toxicity to P. Persimilis. In the greenhouses experiments, the density of T urticae before treatment was 65.3 mites per leaf. However, their density after release about 30 predatory mites per rose abruptly decreased from 3.8 mites at 11th day to zero mite at 20th day. During survey periods, four treatments of fungicides (kresoxim-methyl, myclobutanil, nuarimol, triflumizole) for the control of Sphaerotheca pannosa and one treatment of insecticide (spinosad) the control of Frankliniella occidentalis were applied, and these treatments had no the pesticides had no effect on the predatory mite density. It may be suggested from these results that four acaricides, five insecticides, seven fungicides, and one adjuvant could be incorporated into the integrated T. urticae management system with P. persimilis on rose cultivation.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.66-71
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• 2016

Susceptibility of the predatory mite, Phytoseiulus persimilis to 8 insecticides was evaluated. In treatments with insecticides tested, 78-92% of adult female predators survived after 168 hrs after treatment. Adult female predators treated with insecticides tested produced 62.6-93.4% as many eggs as did control females and eclosion of eggs deposited by treated predators was not affected. Moreover, hatch percentage of P. persimilis eggs and survival of nymphs were not seriously affected by exposure to the insecticides tested. Immatures of P. persimilis survived on the leaf disc treated with insecticides tested and 98-100% of immature predators reached adulthood. Based on the results, insecticides tested are expected to be promising candidates for use in integrated pest management program with P. persimilis.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.173-177
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• 2006

Biological control of Tetranychus urticae by Phytoseiulus persimilis was observed in eggp1ant greenhouse fur spring and autumn season culture. Tetranychus urticae was controlled to low density of less than 1 mite from June 24 after p. persimilis were released 3 times at rate of 10 per plant on June 1, 11, and 18, 2004 in spring season experiment. The population of Tetranychus urticae was also less than 1 mite per eggp1ant leaf from September 1 to October 22 after three times releases of 10 P. persimilis in autumn season experiment. In Phytoseiulus persimilis released plot, the percentage of leaves with T. urticae adults and nymphs were 8.6$\sim$13.3% and 5% or less in spring and autumn season experiment. The density of T urticae was from 1 to 2 on leaves with T urticae adults and nymphs.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.54-62
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• 2004

The selective toxicity of spirodiclofen and fluacrypyrim+tetradifon to the predatory mite, Phytoseiulus persimilis and the tea red spider mite, Tetranychus kanzawai was evaluated. The bean leaf discs with adult females or eggs of both species were sprayed with several concentrations of spirodiclofen or fluacrypyrim+tetradifon. Spirodiclofen and fluacrypyrim+tetradifon were much less toxic to P. persimilis than to T. kanzawai. Although the survival rate of adult females of P. persimilis tended to decrease with increasing concentrations of spirodiclofen, 92-68% of predators survived at concentrations of 22.5-180 ppm. Likewise, reproduction was reduced with increasing spirodiclofen concentration. Spirodiclofen did not affect the hatch of P. persimilis eggs. Survival of immature predators decreased with increasing spirodiclofen concentration, however, 88-20% of immature predators reached adulthood at 22.5-90 ppm. In the case of fluacrypyrim+tetradifon, the survival rate of adult females of P. persimilis tended to decrease with increasing concentrations of fluacrypyrim+tetradifon. However, 94-72% of predators remained alive at concentrations of 22.5-180 ppm. Likewise, reproduction was reduced with increasing fluacrypyrim+tetradifon concentration. Fluracypyrim+tetradifon did not affect the hatch of P. persimilis eggs. Survival of immature predators decreased with increasing fluacrypyrim+tetradifon concentration, however, 100-86% of immature predators reached adulthood at 22.5-180 ppm. Based on the results, spirodiclofen and fluacrypyrim+tetradifon appeared to be promising candidates for use in integrated mite management programs where P. persimilis is the major natural enemy.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.151-155
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• 1999

Biological control of Tetranychus kanzawai by Phytoseiulus persimilis on the Angelica utilis was done in 'walk-in' plastic tunnels. The population of T. kanzawai nymphs and adults per 4 cm2 in damaged leaf decreased from 25 mites on July 22 after 25 predatory mites per m2 were released on July 23 to 0.4 mites on September 9 and then rose to 9.3 mites on October 16, 1997. Phytoseiulus persimilis could suppress T. kanzawai to low population level from August 13 to October 1.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.383-391
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• 2020

The vertical distribution and dispersion of the two-spotted spider mite, Tetranychus urticae and its predator, Phytoseiulus persimilis, were investigated within and between green pepper plants. We also tested the effect of an artificial bridge with threads on dispersal of P. persimilis between the plants. The extent of spread of T. urticae depended on its infested density and location. When 10 adults of T. urticae were inoculated on upper leaf, they stayed on the upper leaf until 5 days after inoculation. However, when 100 adults were inoculated on an upper leaf, they dispersed to the lower leaf within a day. In condition that 10 adults of T. urticae were inoculated on the lower leaf, they started to move toward upward within a day. In the absence of T. urticae, P. persimilis tended to move to the leaves where T. urticae was present when both T. urticae and P. persimilis were inoculated together within a plant. An artificial bridge with threads between two plants was helpful to disperse P. persimilis to neighboring plants. Therefore, it would be expected that the dispersal of P. persimilis can be promoted by supplying the artificial bridges among plants and by narrowing the distances between plants.

• Korean Journal of Organic Agriculture
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• v.14 no.3
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• pp.315-323
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• 2006

The potential of the predatory mite Phytoseiulus persimilis (Acarina : Phytoseiidae) to control two spotted spider mite Tetranychus urticae (Acarina : Tetranychidae) was investigated on sustainable strawberry fields in Jeonnam area. The density of T. urticae increased from 4th and 7th weeks after single and two timings release P. persimilis, respectively. On the three timings of release plot, number(density) of T. urticae on a leaf maintained fewer than 10 during the 15 weeks after release. In the 1,000 release of P. persimilis per $100m^2$ plot, P. persimilis could not suppress T. urticae. In the 2,000 release plot, P. persimilis could suppress T. urticae with low density which was the similar in the 3,000 release plot. Two-spotted spider mite, T. urticae, occurred from late March and increased density in Hampyeong area. In the P. persimilis released field, T. urticae inhibited continuously after release. In Boseong area, density of P. persimilis increased 50 per 10 leaves through increasing of T. urticae. Percent of occurrence of T. urticae showed high $10.5{\sim}75.5%$ in none-release predatory mite but not high in release treatment. T. urticae on sustainable strawberry field could be inhibited by P. persimilis.

• Korean Journal of Organic Agriculture
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• v.27 no.3
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• pp.327-339
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• 2019

The differential susceptibility of the two spotted spider mite, Tetranychus urticae and its predator, Phytoseiulus persimilis against extracts of Gleditsia japonica var. koraiensis, Camellia sinensis, Cinnamomum cassia, Lantana camara and their mixtures was evaluated. The plant extracts tested were much less toxic to P. persimilis than to T. urticae. The plant extracts tested had little effect on the survival of P. persimilis adult females. Moreover, reproduction of P. persimilis adult females and eclosion of eggs deposited by treated predators were not seriously affected. The treatments of the plant extracts tested showed no serious toxic effect on P. persimilis eggs and exhibited 84~100% hatchability. The treatments with mixtures 3 and 1 were effective against the adult females of T. urticae and yielded 76.0% and 72.7% adulticidal activity at 7 days after treatment, respectively. The treatment of mixture 2 revealed 63.3% adulticidal activity. Generally, the acaricidal activity of the individual treatment of each plant extract was lower than the mixtures. The adult females of T. urticae treated with mixtures 3 and 1 produced only 29.5~31.3% as many eggs as the control females did. All the plant extracts tested exhibited no noticeable toxic effect to the eggs of T. urticae. These results suggest that mixtures 3 and 1 might be used for the control of T. urticae, and expected to be promising candidates for use in integrated mite management program with P. persimilis.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.975-985
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• 2015

The susceptibility of the twospotted spider mite, Tetranychus urticae and the predatory mite, Phytoseiulus persimilis to extracts of Melia azedarach, Piper nigrum, Syringa velutina and their mixtures was evaluated in laboratory bioassays. Treatments of mixture 1 and 2 were effective against adult females of T. urticae and yielded 73.3 and 70.7% adulticidal activity at 7 days after treatment, respectively. Treatment of mixture 3 revealed 62.7% adulticidal activity. However, M. azedarach, P. nigrum and S. velutina had lower adulticidal activity than the other treatments. Adult females of T. urticae treated with mixture 1 and 2 produced only 11.1-16.7% as many eggs as control females did. All the plant extracts tested were ineffective to against the eggs of T. urticae. Plant extracts tested had little effect on the survival of P. persimilis adult females. Moreover, reproduction of P. persimilis adult females and eclosion of eggs deposited by treated predators were not seriously affected. Treatment of plant extracts tested showed no toxic effect on P. persimilis eggs and produced 100% hatchability. These results suggest that mixture 1 and 2 might be used for the control of T. urticae, and expected to be promising candidates for use in integrated mite management program with P. persimilis.

• Journal of Sericultural and Entomological Science
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• v.52 no.2
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• pp.155-158
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• 2014

Biological control of Tetranychus urticae by Phytoseiulus persimilis was carried out on tropical plant (Erythrina caffra, Phytolacca dioica) from April to July. Experiments were conducted at Tropical Plant Resources Research Center of Korea National Arboretum. Phytoseiulus persimilis (200 individual/tree) was released once (12. May) to control Tetranychus urticae. We measured the density of leaf-feeding T. urticae at intervals of approximately 2weeks after introducing P. persimilis. The densities of T. urticae were suppressed 10%, in Erythrina caffra and 49% in Phytolacca dioicas after 2 weeks introducing them.