• Korean journal of applied entomology
• /
• v.53 no.4
• /
• pp.465-472
• /
• 2014

The tobacco whitefly, Bemisia tabaci, infest the Oriental melon and give significant economic damage along with its virus-vectoring activity. Various biotypes of B. tabaci have been well known and are classified depending on the severity of crop damage and insecticide susceptibility. In this study, B. tabaci adults were collected in the melon fields located in Poongchun-myeon, Andong, Korea and diagnosed on their biotypes using PCR molecular markers. From the all the 11 greenhouses, B. tabaci biotype Q was identified. In addition, biotype B adults were also found from the 4 greenhouses. These results report the first occurrence of B. tabaci at the Oriental melon farms in Gyeongbuk province with mixed infection by the two biotypes in the area.

• Korean Journal of Environmental Agriculture
• /
• v.3 no.2
• /
• pp.43-49
• /
• 1984

The acute toxicity of an insecticide cartap to several species of freshwater animals was evaluated in the laboratory with special reference to the species specificity, effects of water temperatures and pH values. The aquatic animals tested were the Carassius auratus L., Aphyocypris chinensis $G{\"{U}}NTHER$, Misgurus anguillicaudatus CANTOR, Moina macrocopa STRAUS. The susceptibility of aquatic animals to cartap was different with the species of animals. At the water temperature of $25^{\circ}C$ and pH 7, TLm values of the insecticide to the C. auratus L., A. chinensis G. and M. anguillicaudatus were 0.88, 0.26 and 0.13 ppm in 48 hours, respectively, and to Moina macrocopa S., 306 ppm in 3 hrs. In the case of the three species of fish, TLm 48 values were significantly decreased with rise in temperature. In the case of water flea, where TLm value was 107 ppm at $20^{\circ}C$, there was no consistent response to temperature change, with the highest figure at $25^{\circ}C$ than at either 20 or $30^{\circ}C$. and the susceptibility of C.auratus L. and A. chinensis G. greatly decreased with the increase of pH in water. The toxicity to M. anguillicaudatus and M. macrocopa was significantly higher at pH 9 than at pH 6 or 7. In conclusion, the toxicological reactions of the freshwater animals to cartap were variably influenced by the water temperatures and pH values of water and species of animals.

• The Korean Journal of Pesticide Science
• /
• v.12 no.3
• /
• pp.262-269
• /
• 2008

This study was performed to investigate the toxicity of 39 registered insecticides to the susceptibility, systemic effect, and residual effect and control effect against Pine sawyer beetle, Monochamus saltuarius. Eleven kinds of chemicals such as fenitrothion, fenthion, phenthoate, phosphamidon, dinotefuran, actamiprid, clothianidin, thiacloprid, thiamethoxam, esfenvalerate+fenitrothion, and fipronil were showed 100% insecticidal activity both in body spray and twig dipping bioassay. Among these chemicals, fenitrothion and fenthion were showed 100% insecticidal activity when sprayed at 4000 times diluted solutions, and phenthoate, thiacloprid, thiamethoxam and fipronil were showed 100% insecticidal activity when sprayed at 2000 times diluted solution. Root systemic effect was showed 100% mortality in phosphamidon, clothianidin, thiamethoxam, and 77.7% in thiacloprid. In residual effect, fenitrothion and thiamethoxam were showed 80% mortality fifteen days after treatment (DAT), and fenthion, phosphamidon, clothianidin were showed 80% mortality ten DAT, fenitrothion, thiamethoxam, fipronil showed 100% mortality in seven DAT, thiacloprid was showed 100% mortality in three DAT. Fenthion and phenthoate were showed 100% mortality one DAT. In the control effect, 6 kinds of chemicals were showed 100% mortality one DAT and all chemicals showed 100% mortality three DAT.

• Korean journal of applied entomology
• /
• v.26 no.2 s.71
• /
• pp.83-88
• /
• 1987

Differences in susceptibility of several organophosphate, carbamate and pyrethroid insecticides to three species of aphids were determined by leaf-dipping and spray methods. The insects tested were the apterous adults of the green peach aphid (Myzus persicae), cotton aphid (Aphis gossypii) and soybean aphid (Aphis glycines). The comparison of $LC_{50}$ levels was indicated as follows; (1) The susceptibility to insecticides tested were greatly varied with the test methods. (2) The leaf dipping method is more recommendable than the spray method for insecticide screening with aphids. It was easier, more accurate and less variable than the latter. (3) The susceptibility to insecticides was greatly varied between the aphid species. Soybean aphid was more susceptible to the insecticides than green peach aphid and cotton aphid. Exceptionally, pirimicarb was not effective on the cotton aphid.

• Journal of Korean Society of Forest Science
• /
• v.85 no.3
• /
• pp.439-442
• /
• 1996

In this study, we tried to figure out the ecology of Masakimyia pustulae Yukawa et Sunose which attacts evergreen euonymus and results in scenic damage caused by early falling of leaves and may increase the susceptibility for anthrocnose. In addition, we tried to develope a method for the control of the insect to prevent spreading of the damage by use of insecticide. The results obtained from the study were as follows : 1. Masakimyia pustulae emerged from late April to late May at Chuncheon area. Average length of the adult insects was $1.88{\pm}0.43mm$, and the life span of them reached about 11 hours. The sex ratio of the insect was 56 : 44(female : male), and they ovipositied $90{\pm}28$ eggs. The shape of eggs was oval with average length $0.32{\pm}0.013mm$. The length of larvae averaged $1.64{\pm}0.25mm$ and started pupation from mid-March, which took about 40~50 days, although there was variance due to temperature variation in each spring. 2. The 3% powder of carbofuran treatment by burying $200g/m^3$ of the insecticide around the damaged tree during mid-March with additional burying about a week after pupation showed good result for the control of the insect, which resulted in more than 96.2% removal of the insects.

• The Korean Journal of Pesticide Science
• /
• v.13 no.3
• /
• pp.197-202
• /
• 2009

Based on the insecticidal efficacy by insecticide treatment methods, neurophysiological responses were compared with the larvae of diamondback moth (DBM) and beet armyworm (BAW) using pyrethroids working on nervous system. By body spray method, all pyrethroids were showed lower insecticidal activity below 50% on the larvae of DBM and BAW. By leaf dipping method, DBM larvae were showed the insecticidal activity as 100% at 50 ppm deltamethrin, 80.0% at fenvalervate and 63.3% at permethrin. However, BAW larvae were showed lower insecticidal activity as similar as control in all concentration. In order to examine electrophysiological response on nervous system on DBM and BAW larvae when treated three insecticides, we investigated the voltage and reaction degree. The voltage of DBM were responded as high as $10^{-7}M$ in deltamethrin, $10^{-5}M$ in fenvalerate and $10^{-3}M$ in permethrin. However, those of BAW were showed dull responses with small variation of voltage to all three insecticides.

• Korean journal of applied entomology
• /
• v.63 no.1
• /
• pp.33-42
• /
• 2024

The green peach aphid, Myzus persicae is a representative agricultural insect pest that is polyphagous and causes serious damage to tobacco, potatoes, peppers, cabbage, and peaches. In this study, we analyzed the level of development of insecticide resistance to λ-cyhalothrin, imidacloprid, and flupyradifurone and the point mutations (R81T, L1014F, M918L) in 12 field populations of M. persicae. In addition, the expression level of CYP6CY3, a cytochrome P450 gene, was analyzed through qRT-PCR. As a result, λ-cyhalothrin showed high resistance ratio (RR) of > 200 in all 12 populations. Imidacloprid and flupyradifurone showed high RR of >200 in YS, UR, HY, and WJ populations. The R81T was detected in approximately 50%, L1014F in approximately 33.3%, and M918L in 100% of the 12 populations. Additionally, the expression level of subunit CYP6CY3 was highest in imidacloprid-resistant population (YS). These results suggest that M918L point mutation can be used as λ-cyhalothrin-resistance molecular diagnostic and R81T point mutation and the high expression of CYP6CY3 can be used as imidacloprid-resistance molecular diagnostic markers.

• Korean journal of applied entomology
• /
• v.63 no.1
• /
• pp.53-61
• /
• 2024

The susceptibility of Aphis gossypii populations collected from three fields (WJ, CC, and GS) was evaluated to three insecticides (afidopyropen, chlorfenapyr and cyantraniliprole) and three binary mixtures. Three field populations showed resistance ratios of over 100 to all insecticides. The Combination Index (CI), %M_(synergism), Co-Toxicity Coefficient (CTC), Wadley Ratio (WR), Synergism Ratio (SR) and Abbott Ratio (AR) were used to evaluate combined effect of the insecticides. Afidopyropen + chlorfenapyr (CI ≤ 0.16; %M_(synergism) ≥ 94; CTC ≥ 764.5; WR ≥ 6.4; SR ≥ 6.9 and AR ≥ 1.1) showed a synergism in all filed populations. WJ and CC populations showed a synergism in all binary mixtures of insecticides, but GS population showed an antagonism for chlorfenapyr + cyantraniliprole (CI, 1.63; %M_(synergism), 30; CTC, 64.0; WR, 0.6 and AR, 0.54) and afidopyropen + cyantraniliprole (CI, 6.7; %M_(synergism), 1; CTC, 19.8; WR, 0.2 and AR ≤ 0.55). All mixtures (afidopyropen + chlorfenapyr, chlorfenapyr + cyantraniliprole and afidopyropen + cyantraniliprole) showed a control value of over 99% after 21 days of treatment in the field. This study highlights that binary mixtures of three insecticides serve as an effective control strategy for A. gossypii.

• Korean journal of applied entomology
• /
• v.61 no.4
• /
• pp.529-537
• /
• 2022

The susceptibilities of five insecticides to the larvae of Spoladea recurvalis, a major pest of spinach, were evaluated. Lufenuron EC, chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed 90% or more insecticidal activity at dilution concentrations of 2 (12.5 ppm), 4 (12.5 ppm), 8 (2.5 ppm), 4 (20.0 ppm), and 8 (12.5 ppm), respectively. At their recommended concentrations, Chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed very high insecticidal activity of 98.3%, 100%, 95.0%, and 100%, respectively, after 72 h on S. recurvalis larvae exposed after 7 days of treatment. Field tests at two spinach greenhouses in Hwaseong and Yeoncheon showed a high control effect of over 90% after 7 days of treatment in both areas. In addition, the insecticides can be used as exclusive agents for S. recurvalis that occurs in spinach, as there is no phytotoxicity even at double doses.

• Korean journal of applied entomology
• /
• v.39 no.3
• /
• pp.199-205
• /
• 2000

The field control efficacy of entomopathogenic nematode, Steinernema carpocapsae Weiser, was evaluated on the beet armyworm, Spodoptera exigua (Hiibner). The insect pest has been known to be a defoliator at the aerial part of the crop and difficult to be controlled effectively with most commercial chemical insecticides due to its insecticide resistance. To overcome the susceptibility of the nematodes to desiccation when they were applied by leaf spray in field condition, we screened several commercial antidesiccants (alkyl glucoside, CMC, glycerol, Keltrol-F, Kunipia-G, and Laponite LXG) optimal for survival of the nematodes. Keltrol-F (0.1 %) was selected as a candidate supplement for field application of the nematodes. Leaf spray of the nematodes at 5,000 infective juveniles/ml of distilled water containing 0.1 % Keltrol-F resulted in 87.7% control efficacy on the 3rd instar larvae of Sp. exigua.