In order to renovate spirodiclofen contaminated soil through biodegradation, a high-effective spirodiclofen degrading bacterium was isolated from corn cultivated soil in Weifang of Shandong, China using enrichment culture and HPLC method. The strain identification was studied, the best cultivated conditions and pesticides degrading substrate range of the strain was also determined. The spirodiclofen degradation rate of the screened strain WF14-6 was 76.42% after 120 h cultivation, based on morphology and 16S rRNA gene sequence analysis, the strain was identified as Enterobacter sp. The best cultivated temperature and pH of the strain were 30℃and 7.0. After 72 h cultivation, the degradation rate of strain to imidacloprid and acifluorfene was 31.35~41.06%, the degradation rate to bupirimate、diafenthiuron and dimethomorph was 20.81~23.90%.

The acaricidal activity of Asarum heterotropoides root-derived principles, methyleugenol, safrole, 3-carene, α-asarone, pentadecane and A. heterotropoides root steam distillate constituents was tested against poultry red mites Dermanyssus gallinae (De Geer). All active principles were identified by spectroscopic analysis. Results were compared with those of two conventional acaricides, benzyl benzoate and N,N-diethyl-3-methylbenzamide (DEET). Methyleugenol (24 h LC50 = 0.57 μg/cm2) and safrole (24 h LC50 = 8.54 μg/cm2) were the most toxic compounds toward D. gallinae, followed by 3,4,5-trimethoxytoluene, 3,5-dimethoxytoluene, estragole, α-terpineol, verbenone, eucarvone, linalool, and terpinen-4-ol (LC50 = 15.65–27.88 μg/cm2). Methyleugenol was 16.7× and 11.0× more toxic than benzyl benzoate (LC50 = 9.52 μg/cm2) and DEET (LC50 = 6.28 μg/cm2), respectively; safrole was 1.1× and 0.73× more toxic. Asarum heterotropoides root-derived materials, particularly methyleugenol and safrole, merit further study as potential acaricides. Global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments justify further studies on A. heterotropoides root extract and steam distillate preparations containing the active constituents described as potential contact-action fumigants for the control of mites.

본 연구에서는 계피 정유 3종의 구성성분을 분석하였고, 미국선녀벌레에 대한 살충활성을 검정하였다. (E)-Cinnamaldehyde을 포함한 9종의 계피 정유 구성성분과 21종의 유사 물질을 미국선녀벌레 약충에 대해 살충활성을 검정한 결과, hydro-cinnamic acid가 반수치사농도 1.55 mg/cm 2로 가장 좋은 살충활성을 보였으며, geranic acid도 1.59 mg/cm 2로 높은 살충 활성을 보였다. Cinnamaldehyde를 포함한 hydro-cinnamaldehyde, (E)-cinnamaldehyde, cinnamdyl alcohol, cinnamyl acetate, dibutyl phtalate, anethole, a-cyano cinnamic acid, (s)-perillyl alcohol, methyl cinnamaldehyde, bonyl acetate 12종이 중간정도의 활성(1.60 - 4.94 mg/cm 2 )을 보였으며, 다른 물질들은 살충활성이 낮거나 없었다. 미국선녀벌레 성충에 대해서는 eugenol 이 반수치사 농도 10.81 mg로 가장 높은 살충활성을 보였으며, geranic acid (30.68 mg)도 높은 살충력을 보였다. Cinnamaldehyde 등 9종이 반수 치사 농도 105.44~255.76 mg의 살충활성을 보였다. 다른 18종의 물질은 활성이 낮거나 없었다. 실제 포장인 인삼포장에 발생하는 미국선녀벌레에 대한 적용시험에서 cinnamon bark 정유와 cinnamon green leaf 정유가 각각 82.3%와 82.9%의 높 은 살충활성을 보였다. 농업환경에서 고독성 합성살충제의 사용을 줄일 수 있는 방안으로 본 논문에서 선발한 계피정유가 미국선녀벌레의 약충 및 성충 방제에 유용한 수단으로 이용될 수 있을 것으로 사료된다.

The toxicity of cypress (Cupressus sempervirens) and howood (Cinnamomum camphora) essential oils, and its constituents to adult western flower thrips, Frankliniella occidentalis using leaf-dipping bioassay and vapour-phase toxicity bioassays. Both cypress and howood essential oils were toxic to western flower thrips. The most active principles were determined to be linalool, linalool oxide, cis-linalool oxide, trans-linalool oxide, camphor, and 1,8-cineole from cypress and howood essential oils. Linalool (24h LC50, 0.030 µg/cm2), linalool oxide (24h LC50, 0.036 µg/cm2), cis-linalool oxide (24h LC50, 0.043 µg/cm2), trans-linalool oxide (24h LC50, 0.045 µg/cm2), and camphor (24h LC50, 0.10 µg/cm2) were the most toxic. Potent toxicity was also observed with 1,8-cineole, a-pinene, d-limonene, a-terpinene, cinnamaldehyde, b-pinene, 3-carene a-terpineol, camphene, and terpineol (24h LC50, 0.33–0.65 µg/cm2). The spray bioassy of cypress and howood oil formulation (500 ppm) resulted in > 80% mortality toward western flower thrips population. Global efforts to reduce the level of toxic synthetic insecticides in the agricultural environment justify further studies on cypress and howood essential oil-derived materials as potential contact-action fumigants for the control of western flower thrips populations.

The small brown planthopper (SBPH), Laodelphax striatellus Fallen, is an important pest that causes severe yield losses by transmitting plant viruses to rice. For the efficient control of SBPH in Korea, the respective resistance levels in the immigrant and indigenous populations need to be discerned. The resistance levels to 10 insecticides (three carbamates, an organophosphate, four neonicotinoids, and a phenylpyrazole) were evaluated in 21 field populations collected from either SBPH-immigrating or indigenous regions during two different seasons (early spring vs. late summer). Imidacloprid resistance was most widely observed in many regional populations, followed by thiamethoxam resistance. Interestingly, the resistance level to imidacloprid was significantly higher in both immigrant and late-summer-collected populations than in indigenous and early spring-collected populations, respectively [3.3- (p = 0.018) and 2.6-fold (p = 0.026)]. Moreover, the late summer immigrant population exhibited higher imidacloprid resistance (2.4-fold) than the early spring-collected population from the same region, suggesting that the migratory SBPH that immigrated into Korea already exhibited imidacloprid resistance traits and were further selected after inhabitation. All field populations showed little resistance to fipronil (0.1- to 0.7-fold), suggesting that it is the most effective among the tested insecticides to control field populations of SBPH. The coefficient of variation of the resistance ratio (RR) among different regional populations and the correlation coefficient of RR among different insecticides have been suggested as supplementary parameters when determining appropriate insecticides as respective indicators for the dispersion status of resistance among SBPH populations and the possibility of cross resistance among tested insecticides.

An assessment was made of the fumigant toxicity of 20 constituents from catnip oil and another additional five previously identified compounds of the oils and control efficacy of three experimental spray formulations containing catnip oil (1, 0.5 and 0.1% sprays) to females from B- and neonicotinoid-resistant Q-biotypes of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). Spathulenol (LC50, 0.39 μg/cm3) and thymol (0.45 μg/cm3) were the most toxic compounds, followed by carvacrol, α-terpineol, nerol, linalool, menthol and eugenol toward Q-biotype females (0.85–1.24 μg/cm3). The toxicity of these compounds was virtually identical toward both biotype females, indicating that the terpenoids and the insecticides (neonicotinoids and dichlorvos) do not share a common mode of action or elicit cross-resistance. The 0.5% spray of oil formulation resulted in > 80% mortality toward both biotype females. Global efforts to reduce the level of toxic synthetic insecticides in the agricultural environment justify further studies on catnip oil-derived materials as potential contact-action fumigants for the control of B. tabaci populations.

The migratory locust, Locusta migratoria, is one of the famous insect pests in the world. This species reveals several morphological variations; however, it is largely divided into two lineages, Southern (Africa, Southern Europe, Southern Asia, and Australian) and Northern (East Asia, Eurasian continent). In 2014, a large number of L. migratoria with red-brown color were suddenly occurred in the southern region (Haenam-gun, Jeollanam-do) in Korea. Generally, L. migratoria collected in Korea has revealed green color, indicating that the occurrence of the red-brown L. migratoria is unprecedented. In this study, mitochondrial COI sequences of 6 red-brown and 6 green individuals of L. migratoria were analyzed to examine 1) linage of the Korean L. migratoria and 2) co-relation between color and genetic difference. The analysis results reveal that all 12 individuals are belonging to the Northern linage; however, they have genetic divergences from 0% to 0.9%, consisting of five haplotypes. In addition, the red-brown and green individuals did not show genetic differences. Our study suggests that the Korean L. migratoria has genetic divergence which do not related with color differences. Additional studies should be need to examine the origin of the Korean L. migratoria and their geographical relationships.