Tyrosine-mediated cuticle tanning (pigmentation and sclerotization) is a vital process for insect growth and development. In this metabolism, dopamine and N-β-alanyldopamine (NBAD) are major precursors to black melanin-like and yellowish quinonoid pigments, respectively. NBAD synthase (Ebony) catalyzes the synthesis NBAD by conjugation of dopamine and β-alanine, while NBAD hydrolase (Tan) dose a reverse reaction of NBAD synthesis catalyzed by Ebony. In this work, we cloned cDNAs of ebony and tan from two beetle species, Tribolium castaneum and Tenebrio molitor. Loss of function phenotypes produced by RNAi for these genes indicate that Ebony, but not Tan, is required for cuticle pigmentation in both beetles. This work was supported by NRFs (NRF-2015R1A2A2A01006614).

Chitin deacetylases (CDAs) are extracellular-modifying enzymes that deacetylate chitin to produce chitosan. Insect CDAs have been divided into five groups based on phylogenetic analysis. We previously reported the functional importance of group I CDAs, TcCDA1 and TcCDA2, from Tribolium castaneum in molting, morphology of cuticle as well as in movement of legs. However, ultrastructure in the cuticle after RNAi for these genes have not been investigated. In this study, we further analyzed precise localization of these proteins and ultrastructural changes/defects of the cuticles in TcCDA1- and TcCDA2-deficient insects. Loss of function of TcCDA1 and TcCDA2 causes disorganized horizontal laminae and vertical pore canals in both rigid (e.g. elytron and ventral body wall) and soft (e.g. hindwing and dorsal body wall) adult cuticles. These results indicate that TcCDA1 and TcCDA2 are critical for development and formation of the beetle cuticles

Insect cuticle/exoskeleton covering the entire external surface of the body is essential for protecting insects from various environmental stresses. Tyrosine metabolism plays a major role in not only the darkening of cuticle but also its hardening. In this work, we have focused on the functional analysis of nine genes involved in tyrosine-mediated cuticle tanning (pigmentation and sclerotization) pathway in Tenebrio molitor, which has a unique adult cuticle coloration, dark/black dorsal thorax and elytron, and reddish ventral thorax and abdomen. The temporal and spatial expression patterns of the genes were analyzed by real-time PCR, and RNA interference (RNAi) was performed to study the functional importance of these genes in cuticle coloration and/or hardening in T. molitor. This work was supported by NRFs (NRF-2015R1A2A2A01006614 and NRF-2015R1A6A3A04060323).

In the Korean fashion industry, 3D printing systems are considered as new technology and a new opportunity. With 3D printers, consumers can be manufacturers and individuals can develop businesses with little upfront capital. In this study, a dress form for the typical Korean women’s body shape was developed using 3D technology (3D scanning, 3D modeling, and 3D printing). Ten women with apparel sizes 85-91-160 were selected from 3D body-scan data collected by SizeKorea of 201 women aged 25 to 34 (2010). First, 15 horizontal cross-sections were collected from the 3D scan data of the 10 subjects. Then, inside lines of those cross-sections were drawn at 15-degree intervals, and the lengths were measured. The average of the inside lines was connected to the internal spline curve, and the curves were used as the average cross-sections. The average torso body and the dress form of Korean women were developed into a 3D solid model using a 3D CAD program (Solidworks 2012). An output mockup was printed by the FDM type’s 3D printing system (Bonbot 1200, Bonbot 3-H4) using PLA material. The dimensions comparing the 3D solid modeling to the 3D printed mockup of the dress form were measured, and minor differences were between 0.00cm and 0.40cm. In the future, 3D printing systems are expected to be in use for various personalized dress forms.

We developed a simple molecular detection tool that rapidly and accurately identifies Spotted wing Drosophila (SWD) without sophisticated instruments or expertise. We first identified a gene that is present in the SWD genome but not in that of any other insect species. Then, we developed the loop-mediated isothermal amplification (LAMP) assay, which was designed based on genomic DNA of SWD specific gene. This LAMP assay detected only genomic DNA from SWD—not from Drosophila melanogaster. In addition, this assay could detect genomic DNA in SWD geographical strains collected from 8 different locations in Asia, Europe, Hawaii, and the USA. Our LAMP assay could be a useful detection tool for identifying SWD rapidly in the field. This work was carried out with the support of the Cooperative Research Program for Agriculture Science & Technology Development (Project No: PJ0116302016).

The habitat of the cockroach varies by species. The German cockroach (Blattella germanica) lives in human dwellings, while the Japanese field roach (Blattella nipponica) lives in a mountainous region. Based on phylogenetic analysis of mtCO I, the two species are closely related to each other and B. germanica is divergent from wild species such as B. nipponica. Their habitats and walking speed differ even though the two species have similar morphology. We hypothesized that habitats might influence walking speed via changes to appendage morphology and enzyme-based physiological differences. We found that phenotype such as appendage length and esterase isozyme expression were clearly different between the two species. These differences might be responsible for the observed difference in walking speed.

To obtain information on the sanitary of indoor environment in greenhouses used for shiitake cultivation, bacteria associated with larvae and imagoes of Sciaridae flies, pest to shiitake mushroom, were isolated and identified. A total of 1,048 bacterial colonies were isolated from the flies’ larvae and 984 bacterial colonies were isolated from the flies’ imagoes. Based on molecular analysis of the 16S rDNA sequence, Achromobacter xylosoxidans and Tetrathiobacter kashmirensis of β-proteobacteria, Enterobacter asburiae and Raoultella ornithinolytica of γ -proteobacteria, Curtobacterium sp. and Microbacterium thalassium of Actinobacteria, and Penibacillus taichungensis of Firmicutes were identified from the colonies of the flies’ larvae. While, Bacillus megaterium, B. thuringiensis, Lysinbacillus sphaericus and L. fusifomis of Firmicutes, Microbacterium thalassium and Citricoccus parietis of Actinobacteria, and Enterobacter asburiae of γ-proteobacteria were identified from the flies’ imagoes. Some of the isolated bacterial species were known be human pathogens. Overall, the results of this study suggested that mushroom fly carrying human pathogenic bacteria is one of sources impact on the sanitary of indoor environment of greenhouses used for shiitake cultivation.

Insect chitinases (CHTs) belong to family 18 glycosylhydrolases and hydrolyze chitin by an endo-type manner. One of the functions of CHTs is in the turnover of chitin-containing extracellular matrices such as the cuticle and peritrophic matrix of the midgut. There are a large number of genes encoding CHT-like proteins in insects, and they have been classified into eleven groups based on phylogenetic analysis. We have investigated functions of a group III chitinase in Tribolium castaneum (TcCHT7) containing a predicted transmembrane segment in N-terminal region. Recombinant TcCHT7 exhibits chitinolytic activity against CM-Chitin-RBV. Immunohistochemical analysis shows that TcCHT7 is localized in newly formed procuticle in elytral cuticles, suggesting that TcCHT7 is released from the plasma membrane of underlying epidermal cells. TcCHT7-deficient pupae and adults fail to undergo wing-expansion and abdominal contraction. In addition, cuticular chitin accumulates in the inner region of the procuticle where disorganized horizontal laminae and pore canals are evident. These results demonstrate that TcCHT7 plays a critical role in the formation of the rigid and soft cuticles of the beetle. This work was supported by NRFs (NRF-2015 R1A2A2A01006614).

Chitin deacetylases (CDAs) are chitin-modifying enzymes that deacetylate chitin to form chitosan. In insects, this modification may contribute to the affinity and/or cross-linking of chitin/chitosan-like polysaccharides for a variety of structural proteins that may lead to diverse mechanical properties of the cuticle. DmCDA1 (serpentine) and DmCDA2 (vermiform) from Drosophila melanogaster play roles in development and morphology of embryonic tracheal tubes. We previously reported the functional importance of TcCDA1 and TcCDA2 orthologs to DmCDA1 and DmCDA2 from Tribolium castaneum, in molting, morphology of cuticle, and movement of legs. In this study, we further analyze ultrastructural defects of the cuticles and leg joints in TcCDA1- and TcCDA2-deficient insects. Loss of function of TcCDA1 and TcCDA2 causes disorganized chitinous horizontal laminae and vertical pore canals of rigid adult cuticle (e.g. elytron). Both proteins are also required for laminal organization in soft cuticle (e.g. hindwing). Morphological analysis of TcCDA1- and TcCDA2A-deficient adult revealed that ruptured tendons between femur and tibia cause the defects in movement of the leg joint. This work was supported by NRF (NRF-2015R1A2A2A01006614).

Pigmentation or melanization is an important physiological event in insects and is involved in cuticle tanning, wound healing and encapsulation as a defensive response. Dopachrome-conversion enzyme (DCE, Yellow) significantly accelerates the melanization of the chorion in mosquito eggs. In this study, we demonstrated functional importance of two ovary-specific yellow genes, AalY-g and AalY-g2, in the Asian tiger mosquito, Aedes albopictus. The transcripts of both genes were detected in the ovary of adult females only 48-72 h after blood feeding. RNAi for AalY-g or AalY-g2 had no effect on fecundity. However, the outermost colorless exochorion of the eggs was fragile and partially peeled off, and initial melanization of the endochorion was significantly delayed. Eggs from control females exhibited high desiccation resistance, whereas those from dsAalY-g- or dsAalY-g2-treated females were collapsed (50-80%) under the air-dry condition. Ultrastructural analysis revealed abnormal morphology of the endochorion and vitelline membrane in the AalY-g and AalY-g2-deficient eggshell. These results indicate that AalY-g and AalY-g2 are critical for integrity and desiccation resistance of the Ae. albopictus eggs. This work was supported by NRFs (NRF-2015R1A6A3A04060323).

Recently, many habitat corridors have been constructed in Korea, but the effect of corridor types, i.e. overpasses and underpasses, on arthropods was poorly examined. Therefore, we compared the effect of habitat corridor types in terms of abundance, species richness, and composition of carabid beetles. As a result, 3,737 ground beetles belonging to 60 species were collected by pitfall trapping across the northwestern forest–habitat corridor–southeastern forest transects in 2015. Abundance and species richness of total carabid beetles in underpasses were significantly lower than overpasses. And species composition of underpasses corridors was significantly different compared to other habitats, such as overpasses and forests. Although more samples are needed to understand the effect of corridor types, the current underpasses may be unfriendly structures to movement of ground dwelling arthropods as well as carabid beetles.

Even though plant protections using chemical pesticides have several advantages, non-specific toxicities to other beneficial insects and humans and rapid development of tolerance and/or resistance of target pests to chemicals are major disadvantages. Recent researches suggested that using double stranded RNA (dsRNA) could be species specific and environmental friendly pest management protocols. However, efficiency of dsRNA treatments are known to be variable according to its application methods. For example, injections of dsRNAs to pests were known to be effective in all species. However, efficiencies of oral application of dsRNAs were known to be dependent on species. Thus, development of tools that could enhance the efficacy of orally treated dsRNAs are utmost important for widening usages of dsRNAs in plant protection. Recently, we found that the efficacy of oral treated dsRNAs to target pests could be enhanced by nano-technologies. I will show how applying nano-technology to dsRNAs enhance the efficiency of dsRNAs. (This work was carried out with the support of the Cooperative Research Program for Agriculture Science & Technology Development (Project title: Studies for biological characteristics of and control methods against the migratory locust, Locusta migratoria, Project No: PJ011630042016), Rural Development Administration).