• Korean journal of applied entomology
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• v.54 no.4
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• pp.303-310
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• 2015

The diamondback moth, Plutella xylostella, overwinters in some protected areas in Korea. Using a sex pheromone trap, the adults were monitored since the occurrence of the overwintering populations. In Andong, P. xylostella exhibited four adult peaks in a year. Biological characters, such as cold tolerance, insecticide susceptibility, and developmental rate, were analyzed and showed a significant variation among different local overwintering populations. Population genetic variation was assessed with molecular markers, in which the initial high genetic variation among the overwintering populations decreased with the progress of seasons. These results suggests that there may be a significant migration of P. xylostella to decrease the genetic variation among the different local populations that are different in biological characters.

• Journal of Mushroom
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• v.12 no.4
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• pp.357-362
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• 2014

Pathogenicity of Steinernema carpocapsae GSN1 strain was evaluated against Morophagoides moriutii larvae. In Petridish tests, insect mortality by the nematode was dose dependent, which increased with dose from 5 to 160 infective juveniles(IJs)/larva. Pathogenicity against fourth-instar larvae was higher than the rate of corresponding second- and third-instar larvae, showing 100% insect mortality with the dose of 40 IJs/$4^{th}$ instar larva and 80 IJs/$2^{nd}$ or $3^{rd}$ instar larvae. Lethal concentration values at 50% ($LC_{50}$) of S. carpocapsae GSN1 strain were 4.2 IJs/$2^{nd}$ instar larva; 8.5 IJs/$3^{rd}$ instar larva; and 2.3 IJs/$4^{th}$ instar larva, respectively. The number of nematodes established in M. moriutii larvae after infection increased in the increment of dose and insect developmental stage. The highest number of nematodes was harvested from fourth instar larvae of M. moriutii at a dose of 160 IJs per larva, showing 22.5 nematodes per insect larva. Nematode reproductive capacity was related to insect developmental stage, showing 6,335 IJs/$2^{nd}$ instar larva, 21,660 IJs/$3^{rd}$ instar larvae, and 88,700 IJs/$4^{th}$ instar larvae.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.387-390
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• 2012

Beet armyworm (Spodoptera exigua), diamondback moth (Plutella xylostella) and tobacco cutworm (S. litura) are insect pests causing damage in many economically important vegetables in Korea. Bacillus thuringiensis, commonly known as Bt, has been available as an alternative insecticide for many years. Five commercial Bt products and the mixtures evaluate the control efficacy against three kinds of moths. These commercial Bt products had high control efficacy against $2^{nd}$ instar of diamondback moth, but didn't show high mortality against beet armyworm and tobacco cutworm. Mixtures of Bt products didn't have synergistic effects to the tested moths. Also application of twice and four times the recommended concentration didn't improve the control effects against the tested three species of moths.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.117-125
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• 1998

Flupyrazofos (O,O-diethyl-O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)thiophosphoric acid ester) is a new organo-phosphorous insecticide. Flupyrazofos has exhibited excellent activity against diamondback moth (Plutella xylostella, DBM), and it is highly activity against rice armyworm(Pseudaleta separata) and cotton caterpillar(Palpita indicae). Flupyrazofos has then revealed outstanding both rapidity and residual action for DBM, although no systemic actions were observed and no cross-resistances were found to the resistance strains (Op-R, Py-R, IGR-R). Also, susceptibilities of five local strains to flupyrazofos were similar to those of the susceptible strain. These results indicate that flupyrazofos has considerable potential for controlling diamondback moth, rice armyworm and cotton caterpillar in field.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.171-178
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• 2011

Bacillus thuringiensis (Bt) is a bacterial biopesticide against insect pests, mainly lepidopterans. Spodoptera exigua and Plutella xylostella exhibit significant decreases in Bt susceptibility in late larval instars. To enhance Bt pathogenicity, we used a mixture treatment of Bt and other bacterial metabolites which possessed significant immunosuppressive activities. Mixtures of Bt with culture broths of Xenorhabdus nematophila (Xn) or Photorhabdus temperata ssp. temperata (Ptt) significantly enhanced the Bt pathogenicity against late larval instars. Different ratios of Bt to bacterial culture broth had significant pathogenicities against last instar P. xylostella and S. exigua. Five compounds identified from the bacterial culture broth also enhanced Bt pathogenicity. After determining the optimal ratios, the mixture was applied to cabbage infested by late instar P. xylostella or S. exigua in greenhouse conditions. A mixture of Bt and Xn culture broth killed 100% of both insect pests when it was sprayed twice, while Bt alone killed less than 80% or 60% of P. xylostella and S. exigua, respectively. Other Bt mixtures, including Ptt culture broth or bacterial metabolites, also significantly increased pathogenicity in the semi-field assays. These results demonstrated that the Bt mixtures collectively names "Bt-Plus" can be developed into potent biopesticides to increase the efficacy of Bt.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.13-18
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• 2007

Morphological characters of adult and immature stages on Elophila turbata (Butler, 1881) belonging to subfamily Nymphulinae, family Crambidae are redescribed base on Korean materials. Also we observed biological characters of this species including host plants, Spirodela polyrhiza(L.) Schleiden, Salvinia natans ($Linn\acute{e}$) Allioni and Lemna perpusilla Torre. And, photographs of adult, genitalia and immature stages are provided.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.1-6
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• 2015

This study was conducted to estimate the economic injury level (EIL) to leaf broccoli (leaf vegetable) by the diamondback moth (Plutella xylostella L.) in 2007 and obtain basic data for pest management. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 1.5 and 2.0 larvae per plant) as initial density were established. We inoculated larvae on cheesecloth covering to survey changes in larval density. When grown for consumption, leaves of broccoli are harvested in periods. High levels of larvae were associated with significant reductions in leaf yield. There were 0%, 15%, 35%, 42%, 44% yield reductions due to a density of 0, 0.5, 1.0, 1.5, 2.0 diamond back moth larvae per plant, respectively, 25 days after larva inoculation. The regression equation used to predict leaf yield based on the number of initial larvae per plant was y = 1636-394x($R^2=0.79^{***}$>). EIL of the diamondback moth on leaf broccoli was 2~3 larvae per 10 plants for a damage level of 5%. The economic threshold was 1~2 larvae per 10 plants. Thus, diamondback moth management should be initiated when 1~2 larvae appear on 10 plants.

• Korean journal of applied entomology
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• v.35 no.4
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• pp.273-279
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• 1996

Based on the material in the Center for Insect Systematics, Chuncheon, Korea and Institute of Biology and Pedology, Vladivostok, Russia, 4 species of tineids are described as new to science: Morophaga parabucepkala sp. nov., Ceratutzcus orientatzus sp. nov., Gerontha ampliptera sp. nov., and G. namhaensis sp. nov. Furthermore 6 species are recognized new to Korea: , and 4 species new to Russian Far East:

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.317-322
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• 2004

Insecticidal activity, systemic and residual effects, and effects on enzyme activities (esterase, acetylcholinesterase, glutathione S-transferase) of indoxcarb were evaluated against Plutella xylostella. The insecticide was very effective against larvae of P. xylostella. Also, indoxacarb showed only residual effect to P. xylostella when applied to vegetable leaves. It inhibited acetylcholinesterase activity, but didn't do esterase and glutathione S-transferase activities.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.227-233
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• 2001

Four polymorphic allozymes were used for genetic analysis of overwintering populations of field diamondback moth, Plutella xylostella (Linne). Different allele frequencies were found among three local populations of Andong, Youngchon, and Yangsan in all loci. Two allozyme loci (acid phosphatase and phosphoglucomutase) showed significant deviation from Hardy-Weinberg equilibrium in allele frequencies among these populations. Estimated Nei's genetic distance varied from 0.0151 between Yangsan and Youngchon to 0.0877 between Andong and Youngchon. Compared with the previous genetic distances in this moth, a little higher genetic differentiation among these overwintering populations suggests that there would be a specific genetic bottleneck in each local population during overwintering period.