In order to develop the D. adamsi breeding technique that is highly likely to be used as an emotional pet insect, the results of the D. adamsi was collected in the large exhibition Jang Tae-san in Daejeon to the indoor breeding began to spawn after 10 days after the training, the egg laying period was 33.6 days, the average number of spawn per female was 27.7, and the period was 11.8 days. D. adamsi larvae bred with food of oak-boiled molted two times, the duration of 1st larvae development was 11.8 days, 2nd larvae 14.5 days, and the third larvae was 29.4, and the larvae were used to build houses using Masato(soil) and in the pupae, and then in April of the following year. D. adamsi has a characteristic to build a house with fallen leaves and spawn one or two eggs in the fallen leaves, and the results of the spawn mat test using fallen leaves, leaf mold and a sawdust, etc., and the number of spawn was high in the Masato was spread about 3 ~ 5cm, and a fallen leaves on a 10 cm or so, and the growth and survival rate of the larvae were also high. Larvae breeding density was 2 ~ 3 ℓ in the container size to raise the object was normal growth, the higher the density mortality was high and the growth was sluggish. Larvae feeding conditions were normally developed in dry fallen leaves and fermented fallen leaves, compared to the sterile fallen leaves, oak sawdust, sterile fallen leaves and oak sawdust was abnormal, the mortality rate was higher than 50%.
The fruit fly, Drosophila melanogaster, is a good model organism in various areas of biological science. Since D. melanogaster has been thought to be adapted to the chemical stress environment caused by the overripen, decay and fermented fruits, identification of the genes involved in chemical tolerance and investigation of their expression patterns are essential for better understanding of the physiological evolution in D. melanogaster. For investigation of the gene expression level, 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 the present study, therefore, we validated the expression stabilities of ten candidate reference genes using three softwares (geNorm, NormFinder and BestKeeper) in D. melanogaster exposed to different concentrations of acetic acid, ethanol and 2-phenylethanol. Although three programs resulted in slightly different gene stability ranks, but overall tbp encoding TATA box binding protein was most stable gene in acetic acid and ethanol exposed fly, while nd encoding NADH dehydrogenase was the most suitable reference gene in the case of 2-phenylethanol treatment. In the comparison of three chemical treatment condition, nd was also suggested to be most optimal reference gene. In addition, optimal number of reference gene for accurate normalization was calculated by geNorm pairwise analysis, and selection of multiple reference genes was suggested to be better for target gene normalization method than use of a single reference gene.
To control an external parasitic mite, a honey bee line possessing high hygienic behavior (HHB) against an external parasitic mite, Varroa destructor, has been bred in South Korea and an assessment method has been necessitated to diagnose HHB line from the low hygienic behavior (LHB) line. Thus, in this study, we developed single nucleotide polymorphism (SNP) markers from whole genome sequencing of each 20 worker bees from HHB and LHB lines of A. mellifera ligustica (Hymenoptera: Apidae). An average of 319,445,977 sequence reads was mapped to the known A. mellifera reference genome (an average of 87.46%). In 2,316,128 and 3,266,756 SNPs from each HHB and LHB line, an average of 93.6% and was located in the intergenic spacers and introns, whereas, the remaining 6.4% was located in the genic region, respectively. Among them 20 SNPs that were fixed at each line possessing within-individual homozygosity were selected and each four SNPs were used to diagnose the two honey bee lines either by typical PCR-restriction fragment length polymorphism method or allele-specific PCR. The remaining six SNPs had the size difference, enabling relatively easy differentiation between the two honey bee lines on typical agarose gel and another remaining six SNPs only has sequence difference including SNP sites. Thus, these SNP markers can be used to diagnose the honey bee line with HHB from LHB line against V. destructor.
Insect-killing fungi have high potential in pest management. A deeper insight into the fungal genes at the whole genome level is necessary to understand the inter-species or intra-species genetic diversity of fungal genes, and to select excellent isolates. In this work, we conducted a whole genome sequencing of Beauveria bassiana (Bb) JEF-007 and characterized pathogenesis-related features and compared with other isolates including Bb ARSEF2860. A large number of Bb JEF-007 genes showed high identity with Bb ARSEF2860, but some genes showed moderate or low identity. The two Bb isolates showed a significant difference in vegetative growth, antibiotic-susceptibility, and virulence against Tenebrio molitor larvae. When highly identical genes between the two Bb isolates were subjected to real-time PCR, their transcription levels were different, particularly in heat shock protein 30 (hsp30) gene which is related to conidial thermotolerance. In several B. bassiana isolates, chitinases and trypsin-like protease genes involved in pathogenesis were highly conserved, but other genes showed noticeable sequence variation within the same species. Given the transcriptional and genetic diversity in B. bassiana, a selection of virulent isolates with industrial advantages is a pre-requisite, and this genetic approach could support the development of excellent biopesticides with intellectual property protection.
In the present study, we make a first report on the complete mitochondrial DNA genome of Leptaulax koreanus, a Korean endemic species, in Passalidae. The mitogenome is 18,730 base pairs with 13 protein coding genes (PCGs), 22 tRNAs, two rRNAs and a 4240 bp long AT-rich region. The overall base composition is 78.4% AT and 21.6% GC. The maximum likelihood analysis inferred that L. koreanus is a sister to other Scarabaeoidea species. The phylogeny suggested that L. koreanus is the basal group of Scarabaeoidea.
최근 기온이 높아지면서 강원도 대관령 감자 재배지로 날아오는 진딧물 발생이 늘어나고 있다. 그 중 복숭아혹진딧물(Myzus persicae)은 전 세계적으로 분포하고 경제적으로 중요한 해충으로, 감자, 고추 등 노지작물에 흡즙을 통한 바이러스 매개하고 생육저하를 일으키는 피해를 주고 있다. 본 연구는 복숭아혹진딧물의 지리적 차이에 따른 집단의 유전적 관계 규명을 통해 기주식물, 메타집단 등의 군집구조 및 발생패턴을 분석하고, 이러한 요인으로 인한 진딧물 집단의 분산 및 이주 관계를 추정하였다. 최종적으로 개체들 간의 집단유전학적 관계규명을 통해 이들의 확산과 비래 양상을 규명하고자 한다.
Origin of Red imported fire ant (RIFA : Solenopsis invicta) is Central America, a tropical climate region. It has settled in the invasive area, causing various problems. In recent, Solenopsis invicta were discovered in Busan in 2017 and then in 2018 at a construction site in Busan, Pyongtaek, Incheon and in Daegu. This study aims to confirm the origin of invasive colonies of Solenopsis invicta. We tried to test previously developed microsatellite markers so that we establish the tracing protocol for molecular epidemiology of RIFA. We justified 66 microsatellite markers already developed using DNA from the RIFA found in Incheon Harbor. As results, 30 markers were selected to facilitate amplification and fragment analysis.
Cymbidium flower is mainly grown for exportation to China and Japan, but detection of a few pests including the cotton aphid, Aphis gossypii (Hemiptera: Aphidae), necessitated post-harvest treatment for casual exportation. Thus, we irradiated electron beam to cotton aphids occurring in cymbidium to establish post-harvest method for casual exportation of the flowers. For cymbidium, six categories of product quality were examined after eight different doses were irradiated (100, 200, 300, 400, 500, 600, 800 and 1,000 Gy). One thousand Gy to cymbidium caused an extreme deterioration only in vase life in both colors compared to control (0 Gy). In the case of cotton aphids, adult longevity decreased from 11.23 (100 Gy) to 4.70 (400 Gy) when four different doses were irradiated (100, 200, 300, and 400 Gy), with control being an average of 20.89 days. The numbers of total first instar nymph produced per adult was not significantly differed among five doses (2.21 ~ 2.74 individuals), but was substantially lower compared to control (an average of 51.46; P < 0.0001). Live F1 nymphs did not develope to adults at all five doses, except for a single nymph at 100 Gy, which was dead right after emergence. The results of probit analysis indicated that majority of adults required 3.33 ~ 7.55 days for 90% mortality at 200 Gy and higher, but at 100 Gy it required 41.56 days. Therefore, higher than 100 Gy might be required for complete control of adult cotton aphids and their F1.
In order to accumulate the ecological information of Drosophila suzukii for export negotiations of domestic strawberry, we weekly monitored occurrence of D. suzukii at three strawberry fields located in Gok-seong, Dam-yang and Hwa-sun using the best combination of trap and attractant from November 2017 to May 2018, the period of strawberry production. Monitoring was carried out at three sites (a hill located 150 meter distant to greenhouse, outside greenhouse and inside greenhouse) in Gok-seong. Drosophil suzukii was trapped at three short periods from November to the beginning of December, from the end of December to the beginning of January, and from April in a hill. At outside greenhouse, D. suzukii was trapped at two short periods from November to the early December and the beginning of May. In inside greenhouse, it occurred once after May 24th. Gok-seong data can be summarized as more occurrence for longer period as the distance to greenhouse increases. Dam-yang occurred once in a short period inside greenhouse and hill, respectively on May. In case of Hwa-sun, D. suzukii did not trapped in whole trapping sites during trapping period, except for the surrounding grape and peach cultivation areas at the end of November. Summarized, no occurrence periods are from November 20th, 2017 to May 14th, 2018 inside greenhouse; from December 11th, 2017 to May 3rd, 2018 outside greenhouse; and from January 8th, 2018 to April 12th, 2018 on a hill. In connection with strawberry culture, the D. suzukii tends to occur at the beginning and the end of the strawberry production period. We expect this result can serve as a helpful data for export negotiation for quarantine.
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.
Whitefly (Hemiptera: Aleyrodidae) pests, including the tobacco whitefly, Bemisia tabaci, and the greenhouse whitefly, Trialeurodes vaporariorum, are economically important in agriculture. With the annual growth of the domestic fresh fruit export market, various quarantine treatment methods are being used to export strawberries of better quality. The objective of the present study was to evaluate the effects of gamma rays on the development and reproductive sterility of B. tabaci and T. vaporariorum. In both species, the eggs were completely inhibited from hatching at 50 Gy, and the emergence of 3rd instar nymphs was completely suppressed at 150 Gy. Some adult B. tabaci and T. vaporariorum spawning occurred at 100 Gy and 70 Gy, respectively; however, at these irradiation levels, F1 hatchability was completely inhibited. Dosimetry results showed that the penetrating power of gamma ray in the strawberry-filled box was the lowest at the mid-box position. Therefore, B. tabaci and T. vaporariorum were placed in the middle of the strawberry-filled box and irradiated. A gamma-ray irradiation of 100 Gy suppressed the development and reproduction of eggs and adults in both B. tabaci and T. vaporariorum. However, the development of 3rd instar nymphs was inhibited at 300 Gy for B. tabaci and 200 Gy for T. vaporariorum. Our data suggest that at least 300 Gy should be used for the control of these two types of whitefly for strawberry export.
For the setting of control timing, the number of overwintering eggs on host plants and population density of Metcalfa pruinosa nymphs and adults was surveyed in the three peach orchards. According to a survey of the overwintering eggs density (∅2~3㎝, 20㎝ branches) of M. pruinosa on host plants, 221.8 in Mugunghwa trees, 189.3 Oak trees, and 152.7 Acacia trees, and 57.0 Peach showed the number of eggs laid. Examined peach branches within the 50cm (∅1~5cm) was not found population densities of M. pruinosa nymphs and adults, and it was also very low in the sticky trap. The peak density of the adult was highest at 5.4 per trap on August 7 after being first investigated on July 16 in a string wrap survey, and then decreased.
In the peach orchard, it is judged that the control of the M. pruinosa is due to be 20 days after the end of the insect hatching, and that distribution of host plants is more important in the outside region than inside region.