The recent increase in the occurrence of common bed bug and tropical bed bug in shared areas highlights the need for rapid species identification at infestation sites, which is crucial for implementing targeted control measures due to differences in genetic and physiological traits. In this study, molecular diagnostic methods were developed using species-specific ITS2 sequences. Both multiplex PCR and loop-mediated isothermal amplification (LAMP) protocols with a DNA release method successfully distinguished between the two bed bug species regardless of developmental stages in 0.5~2.5 hours, even with dead specimens. Especially, LAMP's simplicity and speed make it applicable for rapid and accurate bed bug diagnosis at infestation sites.

Pyrethroid resistance in cockroach populations has been a public health challenge since the 1950s. The pyrethroid resistance in the German cockroach, Blattella germanica, is primarily attributed to knockdown resistance (kdr) mutations (E434K, C764R, and L993F) in the voltage-sensitive sodium channel gene (vssc). In this study, the pyrethroid resistance state of the German cockroach in the Republic of Korea (ROK) was assessed by analyzing the frequencies of kdr mutations using one-step PCR with total RNA. The results revealed that among the 25 populations examined, 14 populations exhibited the L993F kdr mutation, while no other mutations were detected. Since other cockroach species are also commonly found in human dwellings in ROK, the vssc genes were cloned from four other species, including Blattella nipponica, Periplaneta americana, Periplaneta japonica, and Periplaneta fuliginosa. Based on the genomic DNA (gDNA) sequences obtained from the vssc cloning, primer sets were designed to amplify the vssc fragment spanning the L993F mutation for each species and used to monitor the development of pyrethroid resistance in cockroach populations in the ROK. The study will facilitate the implementation of a nationwide monitoring program to assess cockroach resistance and select suitable alternatives.

Medically significant indoor/ectoparasitic insect populations, including bed bugs and head lice, have developed considerable resistance to insecticides due to limited introduction of new genetic traits and the absence of an overwintering barrier. In contrast, outdoor pests like Anopheles and Culex mosquitoes exhibit fluctuating resistance patterns, likely influenced by factors such as overwintering barriers and relatively wider open habitats. Mosquitoes also face selection pressure from diverse sources beyond public health insecticides unlike bed bugs or head lice. Understanding different factors driving resistance among pests is essential for effective resistance management.

꿀벌에 대한 중요성이 인식되고 도시양봉의 수요가 증가하는 가운데 도시양봉에 최적화된 벌통을 제작하였 다. 꿀벌과 도시양봉에 대한 설문를 진행한 결과, 분봉으로 인한 민원이 도시양봉을 하는 데 가장 큰 저해요소로 꼽혔다. 이에 분봉을 방지하여 시민과 어우러질 수 있으며 친환경적인 벌통을 제작하는 데 초점을 맞췄다. 분봉을 방지하기 위해서는 여왕벌의 이탈을 감지하는 자성 센서와 벌들이 분봉을 하고자 하는 욕구인 분봉열을 감지하 는 온도 센서를 설치하여 효율을 파악하였다. 더불어 최근 이상기후로 인한 잦은 폭우와 고열을 견디기 위하여 밀랍을 이용한 벌통 코팅을 진행하였다. 벌통의 바닥에는 트레이를 서랍처럼 분리 설치할 수 있도록 함으로써 무더운 기온에서는 손쉽게 트레이를 빼서 환기에 중점을 두고, 그 외의 조건에서는 트레이를 끼워둠으로써 바닥 에 떨어진 꿀벌의 사체를 주기적으로 수거하여 유전자 분석을 함으로써 꿀벌의 건강 상태를 점검할 수 있도록 하였다. 꿀벌이 해당 벌통으로 인하여 스트레스를 받는지 꿀벌의 주요 스트레스 마커 유전자의 상대적 발현량을 조사한 결과, 일반적인 벌통에서의 발현량 수준과 큰 차이가 없는 것을 확인할 수 있었다. 이처럼 새로이 디자인된 벌통을 이용한다면 이상기후에서도 도시양봉을 하는 데 기여할 수 있을 것으로 기대된다.

In Korea, the Asian honey bee (Apis cerana) and the European honey bee (Apis mellifera) (Hymenoptera: Apidae) are the two most common honey bee species. These two closely related species are known to have different sensitivity levels to various insecticides due to millennia of exposure to different pests and pesticides. It is reported that A. cerana is known to be more sensitive to several insecticides, such as amitraz, fenitrothion, and fipronil, than A. melllifera. Multiple studies investigated toxicological responses and related CYPome in A. mellifera, but little is known in A. cerana. The goal of this study is to elucidate the underlying mechanism of different toxicological responses between two bee species, with an emphasis on cytochrome P450 (P450), a significant enzyme involved in metabolic activities. The differences in basal P450 expression patterns were investigated by comparing the relative expression levels of P450 orthologs in several dissected organisms of each species. To compare the sensitivity against major insecticides, lethal doses of major insecticides relevant to both honey bee species were assessed by topical and oral ingestion bioassays. The determined sublethal doses of insecticides were applied to honey bees, and the inducibility of P450s was investigated by comparing the expression patterns of multiple P450s. From these results, this study eventually attempts to compare the toxicological differences between two Apis species with differences in induced cytochrome P450 expression levels.

The Varroa mite, Varroa destructor, a parasitic mite that afflicts honey bees, has become increasingly resistant to acaricides like fluvalinate due to its widespread use. The target site insensitivity mechanism, mediated by the L925V/M/I mutations in the voltage-gated sodium channel, plays a major role in resistance. Additionally, cytochrome P450 monooxygenases (Cyp450s) appear to function as a metabolic resistance factor; however, no Cyp450-mediated resistance mechanism has been reported to date. The aim of this study was to identify and characterize Cyp450s associated with fluvalinate resistance. A synergistic bioassay confirmed the involvement of Cyp450s in conferring tolerance or resistance to fluvalinate. Correlation analysis between mortality data and the expression levels of Cyp450 genes led to the identification of several candidates that may play a crucial role in fluvalinate resistance. Analysis of tissue distribution patterns revealed that these genes were most abundantly expressed in the cuticle and synganglion. This suggests that, despite their relatively low expression level, they may play a critical role in protecting the target site from fluvalinate due to its predominant expression in neuronal tissues. Functional analysis, in conjunction with baculovirus expression, demonstrated that fluvalinate has high inhibition rates against the recombinant candidate Cyp450s, suggestive of their strong interaction with fluvalinate. We discussed the potential utilization of their expression levels as a molecular marker for diagnosing metabolic resistance in field-collected Varroa mites.

The Varroa mite, Varroa destructor is an ectoparasite that parasitizes honey bees. The widespread usage of acaricides, particularly fluvalinate, has resulted in the emergence of resistance in Varroa mite populations all over the world. The goal of this study is to track fluvalinate resistance in Varroa mite field populations in Korea using both bioassay and molecular markers. To accomplish this, a residual contact vial (RCV) bioassay for on-site resistance monitoring was developed. Early mortality evaluation in the RCV bioassay was effective for reliably separating mites with the knockdown resistance (kdr) genotype, but late mortality evaluation was useful for distinguishing mites with additional resistance factors. The RCV bioassay of 14 field mite populations collected in 2021 revealed potential resistance development in four populations. Quantitative sequencing was used as an alternate method to examine the frequency of the L925I/M mutation in the voltage-gated sodium channel (vgsc), which is related with the fluvalinate kdr phenotype. While the mutation was not present in Varroa mite populations in 2020, it appeared in 2021, rose in frequency in 2022, and was practically ubiquitous across the country by 2023. This recent emergence and rapid spread of fluvalinate resistance within a span of three years demonstrate the Varroa mite's significant potential for developing resistance. This situation emphasizes the critical necessity to replace fluvalinate with alternate acaricides, such as fenpyroximate, coumaphos, and amitraz. A few novel vgsc mutations potentially involved in resistance were identified. Potential factors driving the rapid expansion of resistance were further discussed.

담배가루이(Bemisia tabaci (Gennadius))는 전세계적으로 다양한 작물을 가해하고 있는 흡즙성 해충이다. 국내에서는 1998년에 최초로 유입이 보고되었고 현재 전국에 널리 퍼져 농가에 경제적으로 큰 손실을 주고 있다. 담배가루이의 주 방제방법인 화학적 방제를 위해서는 정확한 약제 저항성 진단을 바탕으로 한 약제 선택이 중요하다. 따라서 본 연구에서는 2020년 6월부터 10월까지 전국 7개도 12지역의 온실에서 담배가루이를 채집하여 잔류접촉법 기반 생물검정 및 분자마커를 통해 약제 저항성을 진단하였다. 그 결과, 작용기작이 다른 5종 약제(dinotefuran, spinosad, emamectin benzoate, chlorfenapyr 및 bifenthrin)에 대해 전국적으로 높은 저항성을 지니고 있으며 유기인계 및 피레스로이드계 약제에 대한 저항성 점돌연변이가 포화상태임을 확인하였다. 이는 약제 저항성 모니터링에 기반한 담배가루이 약제 저항성 관리가 시급하다는 것을 시사한다.