• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.479-484
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• 2011

The number of comstock mealybug, Pseudococcus comstocki (Kuwana) suddenly increased at ginseng fields in Yangpyeong, Gyeonggi-do from mid July to early August. By the late of September just before digging up the roots of ginseng, more than 8 individuals of the comstock mealybug per plant were occurred and evenly dispersed around the roots. Through the bioassay in the laboratory, six environmental friendly agricultural materials (for example, Nobug, Kkagsami, GB-1, GB-2, GB-3, GB-5) containing sophora extract or paraffin oil as main components were selected by the effective control agents for controlling the comstock mealybug. These selected agents showed a quite similar insecticidal activities to 2 insecticides such as clothianidin and thiamethoxam registered in control of ginseng insect pests. Also. in the ginseng field test, the agent containing sophora extract and paraffin oil, like 2 insecticides showed high control effects against the comstock mealybug.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1013-1017
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• 2020

Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) harbor diverse microbial symbionts that play essential roles in host physiology, ecology, and evolution. In this study we aimed to reveal microbial communities associated with two different mealybugs, papaya mealybug (Paracoccus marginatus) and two-tailed mealybug (Ferrisia virgata) collected from the same host plant. Comparative analysis of microbial communities associated with these mealybugs revealed differences that appear to stem from phylogenetic associations and different nutritional requirements. This first report on both bacterial and fungal communities associated with these mealybugs provides a preliminary insight on factors affecting the endomicrobial communities.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.6-13
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• 1990

The banana insect pest species and their damages were surveyed from 9 vinyl hoses of Cheju Island on August in 18. A total of 5 pest species wre found ; banana root weevil (BRW) Cosmopolites sordidus Germar (Curculionidae) a wireworm Melonotus sp. (Elateridae), a spider mite teranychid sp. (Tetranychidae), mulberry mealybud Pseudococcus comstocki (Kuwana)(Pseudococcidae), and common cutworm Spodoptera litura (Fabricius)(Noctuidae). Among them, the BRW which attacked the rhizome of banana plant was newly recorded from Korea. It is assumed that the weevil would be introduced from Japan, Philippine or SriLan-Ka wiht the banana seedlings imported during early 1980's.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.51-62
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• 2022

Numerous insect pests threaten the Korean orchard industry through feeding on various tissues of fruit trees. Generally, the control of economically important orchard pests is based on the use of chemical insecticides. Owing to growing concerns regarding the environmental and human health effects of insecticides, environment-friendly pest control strategies are urgently needed. Pheromones of orchard pests could lead to an environmentally safe control system based on mating disruption or mass trapping. This review summarizes the functions and compounds of known pheromones from 51 orchard pests in Korea. The pheromones identified to date from 14 species in the families Miridae, Aphididae, Diaspididae, Pseudococcidae, Rutelidae, Cecidomyiidae, and Eurytomidae and 26 species in the order Lepidoptera are female-produced sex pheromones that attract only males. In contrast, all known examples for 11 species in the families Alydidae, Pentatomidae, Thripidae and Cerambycidae are male-produced aggregation pheromones that attract both sexes. Research on pheromones in new pests, kairomones in key orchard pests, mating disruption dispensers to generate prolonged release of the pheromones, and trap design and trap location for mass trapping will be required for the expanded use of pheromones and other semiochemicals in orchard pest management in the future.

• Korean journal of applied entomology
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• v.51 no.3
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• pp.207-213
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• 2012

The cryptic mealybug, Pseudococcus cryptus, has been increasingly damaging citrus, particularly those plants grown in plastic greenhouses. This study was conducted to monitor the seasonal phenology of adult male cryptic mealybugs and to determine the timing for control using a sex pheromone trap. Adult males responded to a synthetic sex pheromone and trap color. An increasing number of males were attracted to the traps with increasing concentrations of sex pheromone up to 5 mg. The males occurred annually four times and had three cohorts at a time due to different overwintering developmental stages. After overwintering the adult males began to in mid-late April. A positive correlation was observed between the number of adult males caught in traps and the mean density per twig of all motile stages except first stage nymphs of the cryptic mealybugs. The peak time for the first nymph to occur was estimated from the maximum attraction time of the males, and the cumulative degree days (DD) was 350 DD, similar with the preoviposition period.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.163-170
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• 2012

Nineteen registered insecticides including 8 mixed formulations with buprofezin and 11 single formulations which is not including buprofezin were evaluated by spray application for their toxicity against adult and nymph of citrus mealybug, Planococcus citri. Five mixed formulations with buprofezin such as buprofezin 15EC+acetamiprid 4EC, buprofezin 10SC+clothianidin 3SC, buprofezin 20WP+dinotefuran 15WP, buprofezin 20SC+thiacloprid 5SC, and buprofezin 20SC+thiamethoxam 3.3SC showed high insecticidal activity (>93%) against nymph and adult of P. citri. Insecticidal activities of EPN 45EC, fenitrothion 50EC and methidathion 40EC in organophosphorous group showed 90 to 93% against nymph only. In addition to, insecticidal activities of acetamiprid 8WP, clothianidin 8SC, dinotefuran 20WG and thiamethoxam 10WG in neonicotinoids group showed above 90% against nymph only. In systemic and residual effect, five mixed formulations that was already proved to have high insecticidal activity showed low toxicity with below 60% against $3^{rd}$ instar nymph of P. citri in tomato and rose under greenhouse. Control efficacy of five mixed formulations with buprofezin was above 90%, 80% and 70% at 5 days after treatment (DAT), 10 DAT and 15 DAT, respectively.

• Korean journal of applied entomology
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• v.35 no.2
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• pp.119-125
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• 1996

Temperature-dependent development study for overwintered eggs of Pseudococcus comstocki (Kuwana) wasconducted to develop a forecasting model for egg hatch date. Hatch times of overwintered eggs were comparedat five constant temperatures (10, 15, 20, 25, 27$^{\circ}$C) and different collection dates. A nonlinear, four-parameterdevelopmental model with high temperature inhibition accurately described (R2=0.9948) mean developmentalrates of all temperatures. Variation in developmental times was modeled(~~=0.972w9)it h a cumulative Weibullfunction. Least-squares linear regression (rate=O.O06358[Temp.]-0.07566)d escribed development in the linearregion (15-25$^{\circ}$C) of the development curve. The low development threshold temperature was estimated 11.9"Cand 154.14 degree-days were required for complete development. The linear degree-day model (thermal summation)and rate summation model (Wagner et al. 1985) were validated using field phenology data. In degreedaymodels, mean-minus-base method, sine wave method, and rectangle method were used in estimation of dailythermal units. Mean-minus-base method was 18 to 28d late, sine wave method was 11 to 14d late, rectanglemethod was 3 to 5d late, and rate summation model was 2 to 3d late in predicting 50% hatch of overwinteredeggs. hatch of overwintered eggs.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.77-85
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• 2018

We surveyed 281 sites of tropical plants and 666 sites of fruit plants for three years (2015~2017) on Pseudococcus longispinus and Pseudococcus orchidicola which have not been surveyed domestically. In tropical plants, P. longispinus were found at 34 sites, while P. orchidicola were found at 87 sites. However, both species were not found in fruit plants. The developmental characteristics of P. longispinus and P. orchidicola were investigated under various temperatures. The female nymph of P. longispinus did not develop at $14^{\circ}C$ and the developmental period was the longest at $16^{\circ}C$ for 361.4 days and the shortest at $32^{\circ}C$ for 39.0 days. The longevity of female adult of P. longispinus was the shortest at $28^{\circ}C$ as 71.7 days. The number of offspring was highest at 177.7 at $32^{\circ}C$. The female nymph of P. orchidicola did not develop at $12^{\circ}C$. However, the developmental period was the longest at $14^{\circ}C$ for 184.9 days and the shortest at $28^{\circ}C$ for 21.5 days. The longevity of female adult of P. orchidicola was the shortest at 51.5 days at $28^{\circ}C$. The number of offspring was highest at 143.8 at $28^{\circ}C$. The net reproductive rate ($R_0$) and intrinsic rate of increase ($r_m$) of P. longispinus were 162.3 and 0.127 at $32^{\circ}C$, respectively. The $R_0$ and $r_m$ of P. orchidicola were 98.3 and 0.139 at $28^{\circ}C$, respectively. These results suggest that the optimum temperature of P. longispinus and P. orchidicola was $32^{\circ}C$ and $28^{\circ}C$, respectively. Therefore, we guess that they can never be able to survive the winter of Korea.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.43-51
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• 2003

This study was carried out to develop the forecasting model of Pseudococcus comtocki Kuwana for timing spray. Field phonology and temperature-dependent development of p. comstocki were studied, and its stage transition models were developed. p comstocki occurred three generations a year in Suwon. The 1 st adults occurred during mid to late June, and the 2nd adults were abundant during mid to late August. The 3rd adults were observed after late October. The development times of each instar of p. comstocki decreased with increasing temperature up to 25$^{\circ}C$, and thereafter the development times increased. The estimated low-threshold temperatures were 14.5, 8.4, 10.2, 11.8, and 10.1$^{\circ}C$ for eggs, 1st+2nd nymphs, 3rd nymphs, preoviposition, and 1st nymphs to preoviposition, respectively. The degree-days (thermal constants) for completion of each instar development were 105 DD for egg,315 DD for 1st+2nd nymph, 143 DD for 3rd nymph, 143 DD for preoviposition, and 599 DD for 1 st nymph to preoviposition. The stage transition models of p. comstocki, which simulate the proportion of individuals shifted from a stage to the next stage, were constructed using the modified Sharpe and DeMichele model and the Weibull function. In field validation, degree-day models using mean-minus-base, sine wave, and rectangle method showed 2-3d, 1-7d, and 0-6 d deviation with actual data in predicting the peak oviposition time of the 1st and 2nd generation adults, respectively. The rate summation model, in which daily development rates estimated by biophysical model of Sharpe and DeMichele were accumulated, showed 1-2 d deviation with actual data at the same phonology predictions.