• Korean journal of applied entomology
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• v.42 no.3
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• pp.233-240
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• 2003

The effect of density suppression of Amblyseius fallacis (Garman) against Panonychus citri (McGregor) on citrus tree introduced with some different ratio was investigated. When it was introduced with over 16:1 (Panonychus citri: A. fallacis) ratio, Panonychus citri was suppressed very effectively. And in case of introduced once or two times with 20: 1 ratio when the density of Panonychus citri was reached 0.5 and 1.0 per leaf, the density of A. fallacis was formed highly, but the suppression effect against Panonychus citri was not effective. Also, the density changes of P. citri and A. fallacis on the citrus tree released with 10: 1 ratio (P. citri: A. fallacis) when the density of P. citri was reached about 0.1 per leaf in plastic film house were investigated. In case of released twice at the interval of 10 days, the density of A. fallacis was high and P. citri was suppressed so effectively over two month. On the inside of canopy of the citrus tree planted in plastic film house, the air temperature was much lower than on the outside of canopy, while relative humidity was much higher.

• Korean journal of applied entomology
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• v.41 no.1
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• pp.55-60
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• 2002

Predation amount and density suppression ability of three species of phytoseiid mites (one native, Amblyseius womersleys Schica; two introduced species, Amblyseius fallacis Garman and Typhlodromus occidentalis Nesbit) on Panonychus citri McGregor were examined in laboratory condition (25$\pm$1$\^{C}$, RH 65$\pm$5%, 16L:8D). A. fallacis and T. occidentalis consumed 20.1 and 9.1 eggs of P. citri, respectively, whereas A. womersleyi consumed 1.1 eggs. When each larva, protonymph and deutonymph of P. citri were supplied as prey for 24 hours. A. womersleyi consumed 23.8, 16.5 and 9.0, and A. fallacis consumed 26.1, 18.2 and 7.4, respectively. However, T. occidentalis consumed only 7.8, 4.2 and 4.2. respectively Density suppression ability of A. womersleyi and A. fallacis against P. citri was very high at the release ratios of 20 : 1 (prey : predator). However, T. occidentalis did not regulate P. citri population effectively Developmental periods from egg to adult of A. womersleyi and A. fallacis was 6.1 and 5.9 days at 25$\^{C}$, respectively.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.296-301
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• 2003

This study was conducted to select low toxic insecticides against natural enemies, and to evaluate resistance stability and cross-resistance to resistance strain for the fulfillment of integrated pest management development. Toxicity of imidacloprid and spinosad to Amblyseius cucumeris was relatively low regardless of the adopting test methods. In addition, those to the Amblyseius fallacis was also low by slide dipping method. The slide dipping method was useful to eliminate repellency effect by mites to the tested insecticides. Mortality of A. fallacis to deltamethrin recorded in 1994 and 1999 was 21.6% and 7.4%, respectively. Meanwhile, the permethrin-resistanct strain of A. fallacis was maintained its resistance to deltamethrin. However, the cross-resistance to the newly introduced insecticides namely imidacloprid, fipronil, chlorfenapyr, abamectin, and spinosad. was relatively low.

• Korean journal of applied entomology
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• v.37 no.1
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• pp.53-58
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• 1998

Comparative studies on some ecological characteristics of three phytoseiid mitespecies (one native; Arnblyseius womersleyi Schica, and two introduced species; A. fallacis Garmanand Typhlodromus occidentalis Nesbit) were carried out. The two-spotted spider mite (Tetranychusurticae Koch) was supplied as prey. Under four constant temperatures of 20, 23, 25 and 30f OS$^{\circ}$C,duration of growth from egg to adult for A. womer.vleyi was 11.5, 7.7, 6.7 and 5.6 days. While twoother species needed slightly shorter time but not significantly different. Critical temperature andeffective degree-days (DD) of A. womerslevi females were 83$^{\circ}$C and 1 1 1.6 DD, whereas those of A..fallacis were 10.7"C and 86.0 DD, and those of 7: occidentalis were 10.7"C and 94.1 DD. Also, thoseof males were similar to their females. Average longevity of females of A. womersleyi, A. fallucisand 7: occidentalis were 18.2 k 8.67, 19.6 3~7.18 and 13.0f5.66 days, total fecundity were 34.3 $-11.93, 39.8k 12.64 and 23.6k8.86, respectively. Under four constant temperatures of 20, 23, 25 and30-t0.S$^{\circ}$C, A. womersleyi consumed 9.1 f2.49, 9.7 k2.00, 9.7 f 2.61, and 10.3 k2.33 eggs of 7:urticae throughout their development. A. ,fizlluc~i.sc onsumed 10.2 k 2.52, 9.7 f2.29, 10.7 f 2.37 and10.1 k2.62 eggs, while, 7: occidentalis consumed 1 1.9 k3.43, 14.2 f4.50, 14.8 k 3.2 1 and 12.7 f2.95 eggs, respectively. Gravid females of A. womersleyi, A. f~zllacis and 7: occidentalis consumed11.4f1.59, 12.5k1.43 and 11.7k3.07 eggs, or consumed 11.9f 2.63, 12.4k3.82, and 12.5f 3.73protonymphs of 7: urticae in a day at 25-30$^{\circ}$C.e in a day at 25-30$^{\circ}$C.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.125-129
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• 2001

Some wingless species have evolved take-off behaviors that enable them to become airborne. We examined aerodynamic attributes of dispersal relative to the body size and standing vs. walking postures for three phytoseiids that were suspected to have different take-off behaviors and dispersal abilities, Phytoseiulus persimilis Athias-Henriot, Neoseiulus fallacis (Carman) and N. californicus (McGregor). The average vertical profile of Pp in the walking position was significantly higher than those of Nf and Nc when in walking position. The body height of Nf in the standing posture was significantly greater than the body height of Pp when in the walking position. Cross-section areas also showed similar patterns of difference. Nf in the standing posture would have more than twice the drag force than in walking posture because of more fluid momentum in the wind boundary layer However, Pp in the walking position would have similar drag to Nf in the standing posture because of a higher vertical profile and larger size. Thus we add the scientific evidence of presence and absence of take-off behavior of some phytoseiid mites and evolutionary aspects of aerial dispersal are further discussed.

• Korean journal of applied entomology
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• v.36 no.3
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• pp.237-242
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• 1997

Comparative studies on suppression possibility with three phytoseiid mite species (An.thly,seiu,sw omersleyi Schicha. A. ,fidIrrc~i.Gs arman and T\ulcornerphlorlrotiiu.s oc~c~idetitaliNs esbit) to the two-spotted spider mite (Te~trrrt~yc.Iir~l~l\ulcorner.i\c .(re Kwh) on kidney bean leaves in field and greenhouse were carried out. In the field experiments with the initial prey -predator ratio of 4 : 1. I0 : I and 20: I . A. ,firllrrcis suppressed successfully the prey populations at all three ratios 17 days after the initial infestation. A. wornc,r-;leyi \uppressed the prey population only at the ratio of 4 : 1, while T. oc~c~ideritcr1iw.s as unable to suppress the prey population at all tested ratios. In the greenhouse experiments with the initial prey-predator ratio of 10: 1, A. jil1ltrci.s could suppress the prey population continuously during the infestation period. A. ~~otnc~r,slceoyuil d suppress the prey population for 13 days after the initial infestation, while T. occie1mttrli.s could suppress the prey population for 8 - 23 days after the initial infestation.