Dysmicoccus brevipes (Cockerell), Dysmicoccus neobrevipes Beardsley and Pseudococcus longispinus (Targioni-Tozzetti) are widely-distributed pests that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of these mealybug pests into South Korea remains a primary concern because of their high incidence in interceptions screened during inspection. Hence, these species prompted a modelling effort to assess their potential risk of introduction. Potential risk maps were developed for these pests with the CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 climate change scenario. Results show that D. brevipes, D. neobrevipes and P. longispinus have little potential for invasion in the exterior environment of South Korea due to high cold stress in the 2020s. However, for D. brevipes and P. longispinus, 3 and 86 locations in Jejudo, were predicted to be marginally suitable for this pest under future climate factors, respectively. In that respect, the results of these model predictions could be used to prepare a risk-based surveying program that improves the probability of detecting early D. brevipe, D. neobrevipes and P. longispinus populations.

This study investigated the fumigant activity of phosphine (PH3) on 2 kinds of mealybug (Pseudococcus longispinus and P. orchidicola (Hemiptera: Pseudococcidae)) adults and nymphs. All of the two mealybugs adults showed higher LCT99 values than nymphs, and P. longispinus showed higher tolerance than P. orchidicola in a 12 L desiccator. The absorption of phosphine on 13 nursery plants showed 12.2~41.5% difference depending on the plant. All of the mealybugs treated with phosphine 2 mg/L in 0.5 m3 fumigation chamber for 4 h showed 100% fumigant activity, except P. longispinus adult (approximately 90% at bottom part). However, when the exposure time was increased to 24 h, all of them showed 100% mortality. In the treatment of 10 m3 container, the 24 h treatment of phosphine showed 100% mortality to P. longispinus and P. orchidicola adults and nymphs. In all the experiments, no phytotoxicity of phosphine observed on 13 plants until 1 month after treatment.

A combination using phosphine (PH3) and ethyl formate (EF) was performed to compensate for the disadventages (long exposure time and phytotoxicity) of a single substance. P. longisipinus was more susceptible to mixed phosphine and ethyl formate than P. orchidicola in 12 L dessicator. Mortality of mixed treatment was higher than aggregated mortalities that treated individually, so it indicated to have a synergic effect on each other. Ethyl formate was showed higher adsorption rate than phosphine on imported nursery plants and showed differences depending on the plant. P. longispinus and P. orchidicola was showed 100% mortality when phosphine and ethyl formate was treated as 1 g/m3 and 30 g/m3 for 4 hour in 0.5 m3 fumigation chamber and in 10 m3 container. Phytotoxicity was evaluated to mixture of phosphine and ethyl formate at 1 month after treatment.

국내 분포조사가 되어 있지 않은 긴꼬리가루깍지벌레와 붉은몸긴꼬리가루깍지벌레를 대상으로 3년간(2015~2017년) 281지점의 관엽식물과 666지점의 과수를 조사하였다. 관엽식물의 경우 긴꼬리가루깍지벌레는 34지점에서 발견되었고, 붉은몸긴꼬리가루깍지벌레는 87지점에서 발견되었으나 과수에서는 두 종 모두 발견되지 않았다. 분포조사를 통해 채집한 긴꼬리가루깍지벌레와 붉은몸긴꼬리가루깍지벌레는 실내사육하며 온도별 발육특성을 조사하였다. 긴꼬리가루깍지벌레 암컷 약충은 14℃에서 정상적인 발육을 하지 못하였으며, 16℃에서는 361.4일로 발육 기간이 가장 길었으며 32℃에서는 39.0일로 가장 짧았다. 긴꼬리가루깍지벌레 암컷 성충수명은 28℃에서 71.7일로 가장 짧았으며, 산자수의 경우 32℃에서 177.7마리로 가장 많았다. 붉은몸긴꼬리가루깍지벌레 암컷 약충은 12℃에서 정상적인 발육을 하지 못하였으며 14℃에서 184.9일로 발육기간이 가장 길었으며, 28℃에서는 21.5일로 가장 짧았다. 붉은몸긴꼬리가루깍지벌레 암컷 성충수명은 28℃에서 51.5일로 가장 짧았으며, 산자수의 경우 28℃에서 143.8마리로 가장 많았다. 세대순증가율(R0)과 내적자연증가율(rm)은 긴꼬리가루깍지벌레는 각각 32℃에서 162.3, 0.127이며, 붉은몸긴꼬리가루깍지벌레는 각각 28℃에서 98.3, 0.139로 가장 크게 나타났다. 따라서, 긴꼬리가루깍지벌레와 붉은몸긴꼬리가루깍지벌레의 최적 온도는 각각 32℃와 28℃로 판단되며 국내에서의 월동은 불가능한 것으로 보인다.

Two species of the genus Coccura Šulc, 1908 from Korea are reviewed. Coccura convexa Borchsenius, 1949 and C. suwakoensis (Kuwana and Toyoda, 1915) were recorded from North Korea by the report of Danzig (1980). Although Kwon et al. (2003) described Coccura comari (Kunow, 1880) from South Korea, we found that this species was misidentification of C. suwakoensis. In this study, we suggest that Coccura comari (Kunow, 1880) is to be excluded from the Korean fauna. The occurrence of C. suwakoensis is also recorded from South Korea for the first time, based on the additional populations which were heavily infested on the Chinese fingetree, Chionanthus retusus Lindley and Paxton. A key to the species of Coccura known from Korea is provided with diagnoses and photographs.

가루깍지벌레류인 Pseudococcus viburni Signoret (Hemiptera: Pseudococcidae)는 포도원과 다른 과실 과원에도 피해를 주는 국제적 해충 이다. 이 종은 한국에서 오랫동안 격리되어 왔으며 야외에서의 발생기록은 전혀 없다. 본 연구에서는 한국에서의 P. viburni 부재를 확인하기 위해 전국적으로 감 과수원 533사이트, 사과 및 기타 과수원 144사이트, 묘목원 및 온실 281사이트를 지난 3년간(2015-2017) 조사하였다. 그 결과 P. viburni는 한국의 야외에서나 묘목원 등에서 발생되지 않는 것으로 확인되어 이를 보고한다.

We investigated if Pseudococcus viburni and P. longispinus, the two notorious pest species of mealybugs are foundin Korea. Our survey involved a total of 602 sites all over the country for the last three years. Pseudococcus viburniwas only once referred in Gimpel’s 1983 dissertation on P. affinis group: only one record was noted from Korea amongmany specimens from various countries. However, the species has never been reported from Korea for the last severaldecades and none was found in our thorough survey. We believe there was a misidentification, as noted by the authorregarding the species complex, and conclude that P. viburni does not occur in Korea. On the other hand, P. longispinushas been found in 36 sites, all from imported tropical houseplants in a green house or nurseries. In addition, anothersimilar species has been found from 86 sites. This unknown species was surprisingly best matched with P. orchidicola.Both species could not survive Korea’s harsh winter and they could only survive in a temperature-controlled place suchas nurseries and restaurants.

Pseudococcus orchidicola and Pseudococcus longispinus, a notorious cosmopolitan pest species of mealybugs, known to be distributed indoors in Korea. The effect of temperature on the development of P. orchidicola and P. longispinus was studied. The duration of nymphal period of the two mealybugs at 24 and 28℃ have been recorded. Developmental duration of P. longispinus was longer than P. orchidicola in both females and males. The adult longevity was estimated to 74.9 and 91.1 days at 24℃ for P. orchidicola and P. longispinus, respectively. The average fecundity per female was greater at 28℃. The survival of P. orchidicola and P. longispinus during winter at outdoor was failed.

Pseudococcus longispinus, a notorious cosmopolitan pest species of mealybugs, known to be distributed indoors in Korea since 2002, is found to be mixed with another species, Pseudococcus orchidicola. Finding P. orchidicola as a pest of tropical plants in Korea is rather unexpected because of their main distribution in Pacific area and South Asia. However, all the available information from morphology, molecule and advices on identification from mealybug specialists indicated this is best matching P. orchidicola. Morphological, molecular and some biological notes on P. orchidicola are provided with some adult and nymphal images, and compared with P. longispinus. A full discussion mainly on identity and distribution of P. orchidicola is given.

캄보디아와 라오스에는 지금까지 가루깍지벌레과 25종 및 18종이 각각 보고되어 있다. 2015년 이들 지역에서 가루깍지벌레과14종이 채집 되었으며, 그 중 캄보디아에서 2종[Antonina graminis (Maskell, 1897), Coccidohystrix insolita (Green, 1908)], 라오스에서 5종[Nipaecoccus viridis (Newstead, 1894), Paracoccus marginatus Williams & Granara de Willink, 1992, Phenacoccus solani (Ferris, 1918), Rastrococcus iceryoides (Green, 1908)]을 처음으로 보고한다.

Mealybugs (Hemiptera: Pseudococcidae) are major pests of a wide range of crops and ornamental plants worldwide, and represented by 56 species in Korea. Occurrence of, or damage by, the longtailed mealybug, Pseudococcus longispinus Targioni-Tozzetti has not been reported since 2002. However, for the first time in many years, P. longispinus was reported at Phalaenopsis orchids by Kim et al in 2015. Therefore, the present study aimed to investigate the distribution of P. longispinus which is usually found inside a greenhouse or a building where the host plants are. We have collected 129 mealybug samples at 254 sites from Korea. Among these, 27 of P. longispinus and 62 of an unidentified Pseudococcus species were found mainly in ornamental plants such as Heteropanax fragrans, commonly known as happy trees in Korea. Morphological characteristics of the unidentified mealybug were very similar to those of P. longispinus. However, the genetic variability in COI sequence comparison was significantly different between the two species. Further studies are needed to clarify the valid name for this unidentified species, and we are currently working on it.

In Korea, six mealybug species have been reported on pears. This study investigated the occurrence of mealybugs in 19 pear orchards from 2013 to 2014. Two species, Crisicoccus matsumotoi (Siraiwa) (Hemiptera: Pseudococcidae) and Pseudococcus comstocki (Kuwana) were mainly found. The dominant species was C. matsumotoi identified on 73% of infested fruit. Toxicities of 14 registered insecticides (7 single formulations and 7 mixed formulations) commonly used to control P. comstocki were evaluated to C. matsumotoi nymphs and adults at the recommended concentration. As a results, all insecticides exhibited strong insecticidal activity with 100% mortality of both nymphs and adults. These results indicate that the 14 insecticides can be used in control for C. matsumotoi in field.

Previously study of mealybug faunas of Cambodia and Laos were known to comprise 25 species and 18 species, respectively. Recently, we have collected fourteen mealybug species in Cambodia and Laos from June to July, 2015. Among them, six species are first found in these countries: Coccidohystrix insolita (Green) in Cambodia; and Antonina graminis (Maskell) in both countries; Nipaecoccus viridis (Newstead), Paracoccus marginatus (Williams & Granara de Willink) Phenacoccus solani (Firris) and Rastrococcus iceryoides (Green) in Laos.