Japanese pine sawyer, Monochamus alternatus, is the main pest that mediates pine wilt nematode, Bursaphelenchus xylophilus, that causes serious damage to pine forests. In this study, we studied the strategy to control M. alternatus using entomopathogenic fungi. The fungi were collected from soil by an insect-baiting method and two fungal isolates (Metarhizium anisopliae JEF-197 and JEF-279) showed high virulence against M. alternatus. The Metarhizium isolates were evaluated for insecticidal activity against M. alternatus by spray treatment on live pine trees and wintering trees, and the M. anisopliae JEF-197 showed high insecticidal activity. In addition, the interaction of fungi and M. alternatus were analyzed by RNA-seq. This result can contribute to the development of insect control agents using entomopathogenic fungi.

The fumigation toxicity of carbonyl sulfide to T. castaneum as a storage grain pest was evaluated. Carbonyl sulfide (COS) is registered in Australia for microorganism present in soil, root and fertilizer. the fumigation activity of carbonyl sulfide was investigated in 12 L desiccator for 24 h exposure to eggs, larvae, pupae, adults of T. castaneum. Eggs and pupae were showed 87.3% and 95.6% mortality for 25 mg/L of COS, respectively. Larvae and adults were investigated with 80.0% and 100.0% mortality at 15 mg/L treatment, respectively. Therefore, the eggs of T. castaneum showed the highest tolerance to COS.

The fumigation activity of phosphine (PH3) to T. castaneum as a storage grain pest was evaluated. The lethal concentration time (LCT) value of each developmental stage (egg, early larva, late larva, pupa and adult) of T. castaneum was analyzed in 12 L desiccator. At the T. castaneum larva stages, exposure for 4 h showed low LCT value, especially in early stage larvae (LCT99 = 0.32 mg·h/L) which is very high susceptibility to PH3. However, T. castaneum eggs were observed very high tolerance to PH3 at LCT99 77.47 mg·h/L. Therefore, the fumigant activity of PH3 against T. castaneum can be found to be significantly different depending on developmental stage.

The Shine Muscat grape(Vitis vinifera L.) have high quality and the cultivation area is increasing recentely in Republic of Korea. The total cultivation area of the country('18) is 963ha, and the cultivation area of Gyeongbuk area is 81%, which is 780ha. But the research on pests causing damage in cultivation is insufficient. Recently, the damage caused by Bark beetles is increasing due to the abnormal weather and the increase of the cultivation area of shine muskets. The Bark beetles that occur in the Grape Shine Muskete plantation are Xyleborinus saxesen, which pierce tree trunks and cause the whole tree to die. Xyleborinus saxesen occurred continuously from April to August, and it occurs in Shine Muscat stem damaged by the frostbite. Shine muskets are weak to frostbite, so it is necessary to keep the trees free from frostbite in winter and early spring.

Three ambrosia beetle species, Xyleborus glabratus, Monarthrum mali, and Euwallacea fornicatus belong to subfamily, Scolytinae, showing similar morphology and body size, but their flight capability and patterns showed species-specific. Body length of Xyleborus glabratus and Monarthrum mali was negatively correlated with flight capabilities; shorter beetles performed longer average flights, longer single flights, total flight distance, and total flight time. Elytral length also was negatively correlated with flight distance in X. glabratus and M. mali. Conversely, only average flight time of E. fornicatus was positively correlated with body length, pronotal width, and elytral length. Body length had no effect on the flight velocity of any of the three beetle species examined. Therefore, our results indicate that body size characteristics of ambrosia beetles differentially influence on their dispersal by species.

정읍과 장수지역은 고도 차이로 인해 평균기온이 다르며, 이러한 환경조건은 생물군집에 영향을 미칠 수 있다. 지표서식성 딱정벌레와 거미에 대한 영향을 알아보기 위해 2018년 3월에 지역별로 10지점의 논둑에서 pitfall-trap을 이용하여 조사하였다. 딱정벌레는 정읍에서 42종이 장수에서 30종이 발견되었으며, 작은모래거저리가 가장 많았다. 거미는 두 지역 모두 40종이 발견되었으며, 턱거미가 가장 많았다. nMDS와 MRPP 분석에서 두 지역의 딱정벌레와 거미의 군집조성이 모두 유의적 차이가 없었다. 딱정벌레와 거미의 개체수와 다양성지수 (species richness, Shannon index, evenness 등)도 지역간 차이가 없었다. 하지만 청동머리먼지벌레의 상대밀도는 장수가 12.3%로 정읍의 0.6%보다 컸다. 또한 밭고랑거미는 장수에서 거미 총개체수의 5.6%를 차지하였으나 정읍에서는 채집되지 않았다. 이러한 결과는 두 지역의 환경차이가 딱정벌레와 거미의 전체 군집조성에 미치는 영향은 뚜렷하지 않지만, 일부 종에 대해서는 지역적 특이성을 보일 수 있다는 점을 시사한다.

지리산국립공원 내 딱정벌레목 곤충상 모니터링을 위하여 고도 200m~1000m 사이에 남쪽과 북쪽 사면에 4개씩 총 8개 지점을 대상으로 2018년 5월부터 10월까지 함정트랩(pitfall trap)을 이용하여 정량 조사를 실시하였다. 총 6회 현장 조사를 실시한 결과 확인된 딱정벌레는 총 13과 58종 9729개체가 채집되었다. 이들을 과 수준에서 확인한 결과 대부분은 딱정벌레과(84.96%, 8266개체)에 속한 것으로 나타났으며 송장벌레과(3.36%), 풍뎅이붙이과(3.11%) 순으로 나타났다. 각 지점에서 얻어진 종 수와 개체수를 이용하여 고도별 사면별 딱정벌레 군집 양상을 분석한 결과 많은 차이를 나타내었다. 추후 이들 차이를 나타나게 한 생태학적 원인을 규명할 예정이다.

Females of adzuki bean beetle (ABB), Callosobruchus chinensis (L.), a cosmopolitan field-to-storage pest of legumes, release sex pheromone consisting of two isomeric components, 2Z-homofarnesal and 2E-homofarnesal. Two day old virgin ABB adults were exposed to sub-lethal fumigation doses (LC25=0.0056 and LC50=0.0076 mgL-1) of phosphine (PH3) to evaluate the effects on adult longevity, fertility and sex pheromone production. Longevity (female; P < 0.001, male; P < 0.001), fecundity (P < 0.001) and sterility (P < 0.001) were significantly affected. The GC-MS for solid phase micro extraction exhibited the significant reduction of release of both of the pheromone components; 2Z-homofarnesal (P < 0.0038) and 2E-homofarnesal (P = 0.0009) when the females were exposed to LC25 dose of PH3. This study unveils the detrimental effects of PH3 fumigation on some of the biological parameters of ABB.

The Wolbachia bacterium, one of the most prevalent endosymbiotic bacteria, is known to induce reproductive anomalies in various invertebrate taxa. We investigated Wolbachia infection frequency in 203 Coleopteran insects collected from Korea. Among them 26 species (12.8%) across families proved to harbor Wolbachia. The phylogenetic trees of two Wolbachia specific genes imply that there have been complex horizontal gene transfers and recombination events within and between divergent Wolbachia subgroups. Interestingly, we also find that the infection frequency is noticeably low and incongruent at the family level when compared to other literature cases of Wolbachia infection in beetle species.

Small hive beetle (Aethina tumida Murray, 1867) (SHB) is one of the important pests of bee keeping industry. This species is endemic in sub-Saharan region of Africa that has recently became an invasive and distributing rapidly throughout the world. Recent detections of SHB in Philippines, Brazil and South Korea indicate that SHB has the potential to become a global pest for apiculture and wild bees. Having enough knowledge about the population source of invasion can help understand the pest ecology and develop the control tactics. SHB has invaded to South Korea in 2017 and cause heavy damage to apiaries in Miryang City, in south-eastern part of Korea and the origin of this pest is still unknown. The aim of this study is to evaluate the phylogenetic position and origin of Korean population of SHB. We sampled the SHB from different bee hives in Miryang city and used 922 bp part of cytochrome oxidase subunit 1 (CO1) region of mitochondrial DNA to compare with all previously reported COI sequences of SHB. The result showed that the population of SHB in south Korea is classified with South Africa, Zimbabwe, Madagascar, Canada, Australia and USA populations in one clade and among them, the lowest genetic distance between South Korean and USA populations indicated that most likely the SHB was imported from the United states to South Korea. No genetic difference has been detected between studied sequences from Korean population indicating that the invasion would had happen in one occasion.

In Europe, the cabbage stem flea beetle (Psylliodes chrysocephala) is a specialized insect feeding on Brassicaceae plants. The plants use the glucosinolate-myrosinase defense system, but P. chrysocephala can overcome this chemical defense by detoxification of the emerging ITCs by conjugation with glutathione (mercapturic acid pathway). In addition to known products of the mercapturic acid pathway, previously unreported metabolites were isolated, and their structures were elucidated by means of high resolution mass spectroscopy (HR-ESITOFMS) and nuclear magnetic resonance (NMR). The products found may represent general detoxification products of the mercapturic acid pathway.

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.

Insect cuticle or exoskeleton is an extracellular matrix consisting of three major morphologically distinct layers, the water-proofing envelope, the protein-rich epicuticle and the chitin/protein-rich procuticle. To accommodate growth, insects must periodically replace their cuticles in a process called “molting or ecdysis”. During each molt cycle a new cuticle is deposited simultaneously with degradation of the inner part of the chitinous procuticle of the old one by molting fluid enzymes including epidermal chitinases. In this study, we show a novel role for an epidermal endochitinase containing two catalytic domains, TcCHT7, from the red flour beetle, Tribolium castaneum, belonging to a subfamily (group III) of insect chitinases in organizing chitin in the newly forming cuticle rather than in degrading chitin present in the prior one. RNAi of TcCHT7 reveals that this enzyme is nonessential for any type of molt or degradation of the chitinous matrix in the old cuticle. In contrast, TcCHT7 is required for formation of properly oriented long chitin fibers inside pore canals that are vertically oriented columnar structures, which contribute to maintain the integrity and the mechanical strength of a light-weight, yet rigid, adult cuticle. Because group III chitinases are highly conserved among insect and other arthropod species, these enzymes have a critical role in the higher ordered organization of chitin fibers for development of the structural integrity of many invertebrate cuticular extracellular matrices. This work was supported by NRFs (NRF-2015R1A2A2A01006614 and NRF-2018R1A2B6005106)

Trails of the convergence ladybird negatively affected the brown citrus aphid population. On 3 days after treatment of ladybird trails, the population growth rate of the brown citrus aphid on treatment and control swingle flushes in the test tube were –0.1848 and –0.0385, respectively. In pot experiments, there were no significant differences in population growth rates between treatment and control swingle plants on 3 and 7 days after treatment of ladybird trails. But, on 10 days after treatment, each population growth rate was -0.0415 and 0.1125, respectively so there was significantly different statistically. Thus, our result support the potential practical application of ladybird trails as an effective control agent for managing of herbivorous insect pests in citrus groves.

While the darkling beetle, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is considered a pest of stored products, it does not pose a significant economic threat to this industry. The grains these beetles feed on are often already damaged. However, the beetle is considered the foremost premise pest in the poultry industry in many countries of the world. Recently, the darking beetle has also infested in broiler chicken houses of Korea. The problems caused by this pest are destroying their insulative capability, lowering chick’s overall performance and transmitting pathogenic organisms, and have been substantial economic losses to poultry producers. Therefore, we surveyed the status of infestation and damage of this pest in broiler chicken houses. Because there is no simple one step process that will completely eliminate darkling beetle populations from broiler facilities, we would like to outline further studies on the proper control measures.

The dung beetle, Copris tripartitus, has been listed as an endangered insect in Korea. In contrast to typical genomic characteristics, the 15,457-bp long, the complete mitochondrial genome (mitogenome) of C. tripartitus has a few unusual characteristics. The genome has the trnP-trnT arrangement at the ND4L-ND6 junction, which is found only in two species of Scarabaeoidea, including C. tripartitus, in 53 available species. Twelve protein coding genes (PCGs) have typical ATT and ATG start codons, whereas COII had the start codon GTA, which is unprecedented in Scarabaeidae. The 297-bp A + T-rich region, which is the shortest available in Scarabaeidae, harbors three repeat units (26, 29, and 21 bp), each consisting of duplicated identical sequences interspersed in the A + T-rich region. Phylogenetic analyses were performed using the concatenated sequences of the 13 PCGs and two rRNA genes using both the Bayesian inference (BI) and maximum likelihood (ML) methods for the families Scarabaeidae and Lucanidae that are available for their mitogenomes in Scarabaeoidea. Our consensus phylogeny yielded monophylies of each family and the subfamily Scarabaeinae in Scarabaeidae with the high nodal supports (0.99-1 by BI and 79-100 by ML). Among the three tribes, represented by multiple genera in Scarabaeinae each Oniticellini and Onitini was supported as monophyletic groups with the highest nodal supports (1 by BI and 100 by ML), whereas Onthophagini was non-monophyletic group, presenting the tribe relationships: ((((Oniticellini + Onthophagini [Caccobius, Milichus, Onthophagus]) + Onthophagini [Digitonthophagus, Phalops]) + Onitini) + (Phanaeini + Eurysternini) + Coprini).

Small hive beetles (SHBs) are parasites of bee colonies and is one of the invasive pest species worldwide. In this study, we aimed to investigate a chemical responsible for the attractiveness of a hive to this pest. Based on the laboratory observation, we found the fermented pollen dough (honey bee food) was highly attractive to adult SHBs. Olfactometer bioassay showed the crude methanol extract of this material is attractive to both sexes (> 60%). However, the methanol extracts of fresh honey and pollen patty which we used as a food of SHB were not attractive to the pest. The crude methanol extract of fermented pollen dough was subjected to partitioning with n-hexane, chloroform, ethyl acetate, and n-butanol. The n-hexane and chloroform fractions were attractive > 80% for both sex SHBs. On the other hand, ethyl acetate and n-butanol were repulsive >70% and >80%, respectively. The wandering larvae of the pest showed a reverse response for the solvent fractions observed in adults. HPLC and GC-MS analysis indicated the methanol extract of fermented pollen dough constitute butanoic acid (7.70%), neopentylamine (7.29%), (E)-9-octadecenoic acid ethyl ester (3.89%) and hexadecanoic acid, ethyl ester. While these compounds were not found even in a trace level in the methanol extract of honey and pollen patty. Based on this findings these constituents of the fermented pollen dough were formed by the action of SHB and its larvae and we believe these volatile organic compounds are responsible for attractiveness to SHB as pollen dough undergoes attach by SHB and ferment. We are working on investigating attractiveness of each of these chemicals toward the pest. We recommend further work on these chemicals for their application to control this pest.

Azuki bean beetle (ABB), Callosobruchus chinensis (L.) is a cosmopolitan field-to-storage pest of legumes. Its female sex pheromone consists of two isomeric components, 2Z-homofarnesal and 2E-homofarnesal. Two day old virgin adults were exposed to sub-lethal fumigation doses (LC25=2.80 and LC50=3.32 mgL-1) of ethyl formate (EF) to see the effects on adult longevity, fecundity, sterility and female sex pheromone production. Longevity (female; P < 0.001, male; P < 0.001), fecundity (P < 0.001) and sterility (P < 0.001) were significantly affected. The Gas Chromatography-Mass Spectrometry for solid phase micro extraction revealed that release of both of the pheromone components were not affected by LC25 dose of EF. However, the fecundity (per female/day) was significantly (P < 0.001) stimulated by the tested EF doses when the female adults were treated irrespective of the male treatment, probably revealing a hormetic effect. This study provides insight into the effect of EF fumigation on biological activities of C. chinensis.

Many insects are able to feed on crucifers despite the presence of a potent activated defense system known as the mustard oil bomb. In damaged tissue, mustard oil glucosides (glucosinolates) are hydrolyzed by the enzyme myrosinase to form toxic mustard oils (isothiocyanates). Here, we analyzed how the the cabbage stem flea beetle Psylliodes chrysocephala, a key pest of oilseed rape, copes with this chemical defense. First, we found that P. chrysocephala prevents the activation of ingested glucosinolates by two different strategies, a) by sequestering glucosinolates and b) by converting glucosinolates to desulfo-glucosinolates. Our next aim was to identify the sulfatase enzyme(s) responsible for the detoxification of glucosinolates in P. chrysocephala. Nine arylsulfatase-like genes were identified in the transcriptome of P. chrysocephala, and five of them showed glucosinolate sulfatase activity upon heterologous expression in Sf9 cells. By using RNAi, we confirmed that PcGSS1 and PcGSS2 are active towards benzenic and indolic glucosinolates in P. chrysocephala adults in vivo. However, in feeding experiments, the proportion of sequestered and desulfated glucosinolates ranged from 26 to 35% which suggests that these strategies alone are likely not sufficient to overcome the chemical plant defense. Indeed, P. chrysocephala additionally conjugates isothiocyanates to glutathione and metabolizes them via the conserved mercapturic acid pathway. In summary, the cabbage stem flea beetle avoids isothiocyanate formation by specialized strategies (sequestration and desulfation), but also relies on a conserved detoxification pathway to prevent toxicity of isothiocyanates.

독특한 경관특성과 높은 보존적 가치에도 불구하고, 사구와 관련된 곤충 다양성 연구는 매우 부족한 편이다. 따라서 본 연구에서는 태안해안국립공원에서 주로 관찰되는 사구와 방풍림(해송)에서 서식하는 지표성 딱정벌레류 군집 구조에 대한 비교 연구를 수행하였다. 2014년 6월 중순부터 10월 중순까지 함정트랩을 이용하여 방풍림 5개 지점과 사구 3개 지점을 조사하였다. 조사 결과, 총 2,335개체의 지표성 딱정벌레류를 채집하였으며, 이들은 15속 30종으로 동정되었다. 사구에서는 24종이 채집되었는데, 둥근칠납작먼지벌레(158개체)와 등빨간먼지벌레(153개체)가 우점하였다. 반 면, 방품림에서는 14종이 채집되었고, 둥근칠납작먼지벌레(1,630개체), 윤납작먼지벌레(130개체) 및 붉은칠납작먼지벌 레(42개체)가 우점하였다. 방풍림과 사구의 지표성 딱정벌레류 종 구성의 유사도는 27.4%로 낮았다. 본 연구 결과는 태안해안국립공원에서 발견되는 사구 지형이 방풍림과 비교해서 다른 곤충 군집을 보유하고 있음을 보여주고 있으며, 이는 향후 곤충 보전을 위한 중요한 정보가 될 것이다.