Mosquitoes were collected from three different environments (urban area, migratory bird refuge, and cowshed) in Gyeoungbuk from March to November 2022. A total of 4,701 female mosqutoes were collected: 1,635 from urban area, 2,801 from migratory bird refuge, and 265 from cowshed. Among collected 9 species, Aedes vexans was the most dominant species (50.9%), followed by Culex pipiens complex (31.8%), and A. albopictus (7.1%). In urban area, C. pipiens complex was the dominant species at 75.5%, while A. vexans was the dominant species at 82.3% and 58.9% in respective migratory bird refuge and cowshed. Among 253 pools tested for flavivirus, Japanese encephalitis virus (type Ⅴ) was detected in one pool of C. orientalis collected from the migratory refuge.
Ixodidae에 속하는 일부 참진드기들은 중증열성혈소판감소증후군(severe fever with thrombocytopenia syndrome; SFTS)을 비롯한 질병을 매개하는 공중보건학적으로 중요한 해충이다. 우리나라에서는 2013년 이후로 SFTS 환자 발생수가 지속적으로 증가하는 경향을 보이며, 경상북도는 전국적으로 2번째로 많은 SFTS 환자가 발생하는 지역이다. 본 연구에서는 2019년 경북 상주 지역의 진드기 분포를 조사하기 위해 시민의 생활 반경 주변을 도심 녹지지역, 관리 취약지역 및 농촌지역으로 구별하여 flagging 방법을 통해 진드기를 채집하였고, 채집 진드기내 SFTS 바이러스 보균 여부를 조사하였다. 채집된 진드기 수를 Collection Index (CI = tick number / 1h / 2 people)로 산출한 결과, 상주시 내 총 26개 지점에서 작은소피참진드기와 개피참진드기, 일본참진드기를 포함하는 총 CI 143의 진드기가 채집되었고, 그 중 작은소피참진드기가 96.5%(CI 138)로 우점종으로 확인되었다. 채집된 진드기의 약 92%(131 CI)는 인적이 드물고 시청이나 관계 당국의 관리가 이루어지지 않는 관리 취약지역에서 채집되었으나, 도심의 녹지지역와 농촌 지역에서는 8.4%(CI 12)의 진드기만 관찰되었다. 총 CI 143의 진드기를 26개 pooling 한 후 SFTS 바이러스 존재 여부를 조사하였으나, 모두 음성으로 확인되었다. 본 연구의 결과는 지역주민들로 하여금 진드기 매개 질병으로부터 안전한 생활을 하기 위한 권고 자료로 활용할 수 있을 것으로 기대된다.
바퀴는 혐오감을 줄 뿐만 아니라 여러 종류의 병원체를 기계적으로 전파하는 주요한 위생곤충이며, 바퀴 방제를 위해 독먹이제를 가장 많이 사용한다. 본 연구에서는 4종류(chlorpyrifos, avermectin, hydramethylnon 및 fipronil)의 살충 주성분이 각각 함유된 국내 유통 독먹이제 3종 (Korea Combat Ultra Slim (K-CUS), Korea Combat Power (K-CP) 및 Korea Zaps Dual Bait (K-ZDB))과 미국 유통 독먹이제 3종(US Combat Source Kill Max (US-CSKM), US Hot Shot MaxAttrax Roach Bait (US-HSM) 및 US Raid Double Control Small Roach Bait (US-RDC))의 독일바퀴(Blattella germanica)에 대한 살충효력을 검증하였다. 6종의 독먹이제 중 fipronil을 살충 주성분으로 사용하는 세 가지의 독먹이제(K-CUS, K-CP 및 US-CSKM)가 속효성 및 높은 살충효과를 나타내었다. K-CUS과 K-CP의 살충효력의 지속성을 검정하기 위해 두 제품을 개봉 후 6개월 및 12개월 이후에 추가로 생물검정을 실시한 결과, 두 제품 모두 시간이 지남에 따라 제품 개봉 직후에 비해 살충효 과가 감소하는 경향을 보였지만, 40시간 이내 독일바퀴에 대한 사충률이 90%에 도달하는 것을 감안하면 적어도 이들 독먹이제의 옥내 설치 후 1 년동안은 살충효과가 유지되는 것으로 판단된다.
Haemaphysalis longicornis (H. longicornis) is the most dominant species that accounts for more than 90% of domestic ticks in Korea. It is also a main mediator and propagator of Severe Fever with Thrombocytopenia Syndrome virus. In order to efficient control of H. longicornis, it is essential to obtain the genetic information of pesticide target genes and determine the mutations putatively involved in insecticide resistance. Acetylcholinesterase (Ace) is a target gene of organophosphorus and carbamate insecticides, but no sequence information of Ace is available to date in H. longicornis. Therefore, in this study, we analyzed the transcriptome of H. longicornis and obtained the sequence information of three Ace genes (HlAce1, HlAce2 and HlAce3). Based on the comparison analysis with sequences of multiple ace genes from other hard ticks, mites and insects, three HlAces were grouped in Acari Ace1, Ace2 and Ace3 clade, respectively. Among three HlAces, HlAce1 seems to be major enzyme because of its conserved amino acids involved in catalytic function.
We monitored the population of Haemaphysalis longicornis, in Andong, Gyungbuk from April to November, 2018. Among total 2,994 ticks collected for 8 months, H. longicornis 1,677(56%), H. spp Larva 1,074(35.9%), H. flava 213(7.1%), Ixodes nipponensis 30(1.0%) were identified. In addition, considering the environment, 1,727(57.7%), 907(30.3%), 192(6.4%) and 168(5.6%) ticks were collected in the grassland, graves, copse, mountain path, respectively. In the pathogen diagnosis with PCR using SFTS virus specific primers, positive viruses were detected in H. longicornis, H. flava and H. spp from June to October. The minimum field infection rate of June, July, August, September and October were 0.4%, 0.8%, 1.2%, 0.8% and 2.3%. respectively.
Honey bee, Apis mellifera L., have been widely used as a model organism for biological science because of its highly developed sociality, specialized labor division and passive population management. In order to examine the expression patterns of genes putatively involved in social development in honey bee, quantitative real-time PCR (qRT-PCR) that has been widely used to investigate the expression level of target gene can be used in honey bee study. However, the selection and validation of optimal reference genes is a crucial step prior to running qRT-PCR. In the present study, therefore, the seasonal expression stability of five candidate reference genes in the abdomen of forager and nurse was investigated using three programs (geNorm, NormFinder and BestKeeper), and selected reference genes were validated by the normalization of expression level of vg encoding vitellogenin. Although three programs revealed slightly different gene stability values, overall the combination of two genes (rpS18 and gapdh encoding ribosomal protein S18 and glyceraldehyde-3-phosphate dehydrogenase, respectively) was resulted in the most suitable use for normalization of the target gene in forager. However, a single gene, either rpL32 or rpS18 in the nurse or either rpL32, rpS18, or gapdh in the comparison between foragers and nurses, were suggested to be applied for normalization of seasonal and labor-specific gene expression by qRT-PCR.
Heamaphysalis longicornis is a major vector for Severe Fever with Thrombocytopenia Syndrome (SFTS) virus and the density of the vector has been increasing because of the climate change. The incidence of fatalities due to SFTS is increasing every year. In this study, to evaluate the SFTS transmission by ticks, the density of ticks mediating SFTS was monitored. Tick was collected every month from four different sites (Grass land, Mountain path, Grave, Copse) in Andong with the traps containing dry ice as CO2 attractants. Among 2,572 ticks of 3 species; H. longicornis, H. flava, and Ixodes nipponensis were most abundantly collected from April to August. H. longicornis is the richest species (92.8%), whereas Ixodes nipponensis was the least species (0.8%). The 54.5% of the sample were nymph stage and female/male ratio was 64.3%. According to the pathogene analysis, SFTS virus was detected from H. longicornis adult and larvae stages collected in July and August. In July samples, SFTS virus was detected only from grassland site, but the virus was observed in the sample from all four sites in August. For effective prevention of SFTS, the tick density should be continuously monitored based on the onset time of SFTS with the consideration of habitate, habit & life history of ticks.
Honey bee has been widely used as a model insect for biological sciences because of its sociality and specialized labor division. For the investigation of the seasonal and labor-dependent expression patterns of genes putatively involved in its sociality, quantitative real-time PCR (qRT-PCR) can be applied to quantify gene expression level and selection of reliable reference gene(s) for normalization is an accurate step. In this study, using three softwares (geNorm, NormFinder and BestKeeper), we evaluated seasonal expression stabilities of four reference genes that have been widely used for qRT-PCR in forager and nurse heads. Among four candidates, two genes, rpS18 and gapdh, were suggested to be the optimal reference genes for qRT-PCR.