To identify genes that commonly respond to the treatment of different insecticides, 3rd instar larvae of the diamondback moth, Plutella xylostella, were treated with sublethal doses (<LC10) of chlorantraniliprole, cypermethrin, dinotefuran, indoxacarb and spinosad via leaf dipping. Then, transcriptomic profiles of treated larvae were compared with that of untreated control. A total of 117,181 transcripts in average with a mean length of 662 bp were generated by de novo assembly, of which 35,329 transcripts were annotated. Among them, 207, 153, 336, 360, and 262 transcripts were determined to be up-regulated whereas 117, 47, 92, 115, and 81 genes were down-regulated following treatments with chlorantraniliprole, cypermethrin, dinotefuran, indoxacarb and spinosad, respectively. Finally, with the criteria of >10 X fold change (FC) and p < 0.05 or >4 X FC, p < 0.05 and q < 0.2, the genes commonly over-transcribed in all treated insects were selected and their over-transcription levels were confirmed by quantitative PCR. These commonly responding genes included three cytochrome P450 genes (Cyp303a1, Cyp6a20 and CYP9E2), three cuticle protein genes (LM-8, LM-19 and TM-A3A), lavesin-1, acyl-CoA D11 desaturase, glucose dehydrogenase, nose resistant to fluxetine protein 6, chorion peroxidase and protein yellow. As the five test insecticides have distinct structure and mode of action, the genes identified in this study were suggested to be involved in general chemical defense at the initial stage of intoxication. Their possible roles in tolerance and resistance development were further discussed.
Aphidiinae in Braconidae includes more than 400 species within approximately 60 genera worldwide. Species of Aphidiinae are mostly known as solitary koinobiont endoparasitoids specifically associated with aphid hosts, and some of them are used for biological control. In the present study, two aphiniine species are newly recognized from South Korea based on morphological and molecular study: Aphidius rhopalosiphi de Stefani-Perez 1902 and A. uzbekistanicus Luzhetzki 1960. Although It was very difficult to discriminate two species morphologically, we cleary identified them by using COI (cytochrome c oxidase subunit I) DNA Barcode sequences. Here we present their morphological descriptions, illustrations and barcoding results.
Swarming alates of termite Macrotermes sp. has been accepted as food among people of Benishangul Gumuz zone in west Ethiopia bordering with Sudan. The preference seems to be for the reproductive caste. We assessed the nutritional composition of nymph and alate of Macrotermes sp. of Ethiopia. The adult contained higher amino acids (31%) compared to nymph (21%). However, the distribution of amino acids in the protein was similar (ap. 4:6 essential to non-essential amino acids). Both stages tend to have high fat contents (50%). Fat supplement could be a possible reason behind the human consumption of termites. Beside the bio-prospection of termite as food or oil source, termite foraging would have important evolutionary biology due to their significant amount of energy-yielding nutrients which could presumably be critical resource for development of larger brained hominines.
Nitric oxide (NO) is an immune mediator in several insects. In addition, eicosanoids mediate various immune responses in response to microbial challenges. This study focuses on cross-talk between two immune mediators. Nitric oxide synthase (SeNOS) of Spodoptera exigua was predicted in its cDNA sequence by interrogation to the transcriptomes and validated by RT-PCR against developmental stage and larval tissues. RNA interference (RNAi) of SeNOS suppressed nodule formation of S. exigua larvae against heat-killed Xenorhabdus hominickii. RNAi of SeNOS also suppressed NO levels in fat body and hemocytes along with suppression of PLA2 activity. NOS-specific inhibitor, L-NAME, also inhibited PLA2 activity, but its enantiomer, D-NAME, did not. However, PLA2 of dexamethasone or oxindole did not suppress NO levels in the immune tissues. In addition, X hominickii did not inhibit up-regulation of NO levels. These results suggest that NO signal activates PLA2 to produce eicosanoids to mediate immune responses
Rapid resistance detection of resistance level is most important step to manage the resistant population in Tetranychus urticae in Korea. Residual contact vial bioassay (RCV) and quantitative sequencing (QS) methods were employed to determine the resistance level and applied to measure the resistance level of 46 field population collected from rose, strawberry and apple trees. Most populations exhibited multiple resistance pattern to various types of acaricides. Especially, the resistance levels in mites from rose cultivation area were higher than those from strawberry and apple cultivation areas. The resistance level detection would provide a useful parameter enabling the proactive action for a proper resistant population management for T. urticae.
Ryanodine receptors (RyRs) regulate the contractions of insect muscles by altering intracellular Ca2+ concentration and are the targets of chlorantraniliprole. Here we established two resistant strains of Drosophila melanogaster, which were treated with low or high concentrations of chlorantraniliprole, and their resistance levels were determined on the basis of contact and ingestion toxicities. Compared with the wild type, the two resistant strains did not show any significant differences in contact toxicity. However, they showed significantly increased resistance ratios in ingestion toxicity than that by the wild type. The resistant strains had altered expression levels of RyRs and more enhanced Acetylcholinesterase and Glutathione-S-transferase activities than that by the non-selected strain. These results suggested that the resistance development of chlorantraniliprole in the two strains might be mediated by the activation of detoxification pathways in D. melanogaster.
A series of conserved point mutations in acetylcholinesterase (AChE) confer resistance to organophosphorus and carbamate insecticides in most arthropod pests. However, the mutations associated with reduced sensitivity to insecticides usually results in the reduction of catalytic efficiency and leads to a fitness disadvantage. To compensate for the reduced catalytic activity, overexpression of neuronal AChE appears to be necessary, which is achieved by a relatively recent duplication of the AChE gene (ace) as observed in the two-spotted spider mite and other insects. Unlike the cases with overexpression of neuronal AChE, the extensive generation of soluble AChE is observed in some insects either from a distinct non-neuronal ace locus or from a single ace locus via alternative splicing. The production of soluble AChE in the fruit fly is induced by chemical stress. Soluble AChE acts as a potential bioscavenger and provides tolerance to xenobiotics, suggesting its role in chemical adaptation during evolution.
The telescope to be onboard SPICA (Space Infrared Telescope for Cosmology and Astrophysics) has an aperture diameter of 2.5 m and its imaging performance is to be diffraction-limited at a wavelength of 20 μm at the operating temperature of <8 K. Because manufacturing precise autocollimating at mir- rors (ACFs) with sizes comparable to the SPICA telescope is not technically feasible, we plan to use sub-aperture stitching interferometry through ACFs for optical testing of the telescope. We have verified the applicability of the sub-aperture stitching technique to the SPICA telescope by performing stitching experiments in a vacuum at a room temperature, using the 800-mm telescope and a 300-mm ACF. We have also developed a new method to reduce uncertainties possibly caused by cryogenic and gravitational deformations of ACFs.
We report our research on aluminum mirror optics for future infrared astronomical satellites. For space infrared missions, cooling the whole instrument is crucial to suppress the infrared background and detector noise. In this aspect, aluminum is appropriate for cryogenic optics, because the same material can be used for the whole structure of the instrument including optical components thanks to its excellent machinability, which helps to mitigate optical misalignment at low temperatures. We have fabricated alu- minum mirrors with ultra-precision machining and measured the wave front errors (WFEs) of the mirrors with a Fizeau interferometer. Based on the power spectral densities of the WFEs, we conrmed that the surface accuracy of all the mirrors satised the requirements for the SPICA Coronagraph Instrument. We then integrated the mirrors into an optical system, and examined the image quality of the system with an optical laser. As a result, the total WFE is estimated to be 33 nm (rms) from the Strehl ratio. This is consistent with the WFEs estimated from the measurement of the individual mirrors.
For future space IR missions, such as SPICA, it is crucial to establish an experimental method for eval- uating the performance of mid-IR detectors. In particular, the wavelength dependence of the sensitivity is important but difficult to be measured properly. We are now preparing a testing system for mid-IR Si:As/Si:Sb detectors on SPICA. We have designed a cryogenic optical system in which IR signal light from a pinhole is collimated, passed through an optical filter, and focused onto a detector. With this system, we can measure the photoresponse of the detector for various IR light using optical lters with different wavelength properties. We have fabricated aluminum mirrors which are adopted to minimize thermal distortion effects and evaluated the surface figure errors. The total wavefront error of the optical system is 1.3 μm RMS, which is small enough for the target wavelengths (20-37 μm) of SPICA. The point spread function measured at a room temperature is consistent with that predicted by the simulation. We report the optical performance of the system at cryogenic temperatures.
To realize large-format compact array detectors covering a wide far-infrared wavelength range up to 200 μm, we have been developing Blocked-Impurity-Band (BIB) type Ge detectors with the room- temperature surface-activated wafer bonding technology provided by Mitsubishi Heavy Industries. We fabricated various types of p+-i junction devices which possessed a BIB-type structure, and evaluated their spectral response curves using a Fourier transform spectrometer. From the Hall effect measurement, we also obtained the physical characteristics of the p+ layers which constituted the p+-i junction devices. The overall result of our measurement shows that the p+-i junction devices have a promising applicability as a new far-infrared detector to cover a wavelength range of 100-200 μm.
We present project updates of the next-generation infrared space mission SPICA (Space Infrared Tele- scope for Cosmology and Astrophysics) as of November 2015. SPICA is optimized for mid- and far-infrared astronomy with unprecedented sensitivity, which will be achieved with a cryogenically cooled (below 8 K), large (2.5 m) telescope. SPICA is expected to address a number of key questions in various fields of astrophysics, ranging from studies of the star-formation history in the universe to the formation and evolution of planetary systems. The international collaboration framework of SPICA has been revisited. SPICA under the new framework passed the Mission Definition Review by JAXA in 2015. A proposal under the new framework to ESA is being prepared. The target launch year in the new framework is 2027/28.
We propose a cosmological survey to probe star formation and nuclear activity in galaxies at redshifts of z=2-4 by polycyclic aromatic hydrocarbon (PAH) features using the SPICA mid-infrared instrument (SMI) with a spectral resolution of R=20. We will cover a wavelength range of 20-36 μm that corresponds to z=2-4 for the PAH features (11.3, 7.7, and 6.2 μm). The sensitivity will be 1 X 10-19 W/m2 (5 σ) in case of a reference survey that covers 4 arcmin2 field in a one-hour observation. It corresponds to LIR=2 X 1011 L⊙ at z=3 and will give us more than 10000 galaxies in a 450 hour survey.
Properties of ULIRGs (Ultra Luminous InfraRed Galaxies) are important to understand the cosmic star formation history. To investigate their properties up to z=0.3, we search for ULIRGs identified by using the AKARI/FIS Bright Source Catalogue and the WISE All-Sky catalog. By matching the AKARI 90 μm catalogue with the WISE catalog, we selected 3,452 galaxies. Additionally, combined with the SDSS DR10 spectroscopic data, we selected 952 galaxies with spec-z. We then computed total infrared luminosities using SED fitting technique, and identied 31 ULIRGs, 561 LIRGs and 344 IRGs. For these galaxies, we found an indication that ULIRGs selected by AKARI change the SED shape with redshift (z = 0.1 - 0.3).
We present a summary of our spectroscopic redshift catalogue of 404 sources in the AKARI Deep Field South (ADF-S). We have used the AAOmega spectrograph to target mid-infrared and far-infrared sources selected primarily from AKARI observations in this field for which we were able to obtain optical counterparts. Our sources with identified redshifts include 316 with Hα detections at z 0:345 and 15 sources at z > 1 with MgII or Ly emission lines. About 13% of our z 0:345 sources are dominated by active galactic nuclei (AGN) emission, although many show emission from both star formation and AGNs. The median Balmer decrement is 5.9. Ultra-luminous infrared galaxies (ULIRGs) were found only in the higher-redshift sources. Optical and near infrared data will be available shortly, enabling calibration of the line luminosities and spectral energy distribution (SED) tting for these sources.
The AKARI North Ecliptic Pole Deep Field is a natural location to accomplish deep extragalactic surveys. It is supported by comprehensive ancillary data extending from radio to X-ray wavelengths, which have been used to classify radio sources as radio-loud and radio-quiet objects and to create a catalogue of Active Galactic Nuclei (AGN). This has been achieved by using a radio-optical classification and colour- colour diagrams rather than the more usual way based on spectroscopy Furthermore, we explore whether this technique can be extended by using a far-Infrared (FIR) colour-colour diagram which has been used to identify 268 high redshift candidates.
We report the results of a multi-wavelength study in the North Ecliptic Pole (NEP) deep field and examine the far infrared-radio correlation (FIRC) for high and low redshift objects. We have found a correlation between the GMRT data at 610 MHz and the Herschel data at 250μm that has been used to define a spectral index. This spectral index shows no evolution against redshift. As a result of the study, we show a radio colour-infrared diagram that can be used as a redshift indicator.
We selected 47 DOGs at z ~ 1:5 using optical R (or r' ), AKARI 18 μm, and 24 μm color in the AKARI North Ecliptic Pole (NEP) Deep survey field. Using the colors among 3, 4, 7, and 9μm, we classified them into 3 groups; bump DOGs (23 sources), power-law DOGs (16 sources), and unknown DOGs (8 sources). We built spectral energy distributions (SEDs) with optical to far-infrared photometric data and investigated their properties using SED fitting method. We found that AGN activity such as a AGN contribution to the infrared luminosity and a Chandra detection rate for bump and power-law DOGs are signicantly different, while stellar component properties like a stellar mass and a star-formation rate are similar to each other. A specific star-formation rate range of power-law DOGs is slightly higher than that of bump DOGs with wide overlap. Herschel/PACS detection rates are almost the same between bump and power-law DOGs. On the other hand SPIRE detection rates show large differences between bump and power-law DOGs. These results might be explained by differences in dust temperatures. Both groups of DOGs host hot and/or warm dust ( 50 Kelvin), and many bump DOGs contain cooler dust ( < 30 Kelvin).
We have imaged the AKARI Deep Field with the GMRT radio telescope at 610 MHz, detecting 1224 radio components, which are optically identified with 455 optical galaxies having a mean r0 magnitude brighter of 22.5 (to a completeness limit of 25.4 mag), and an average redshift ~ 0.8.
The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field (5.4 deg2), using 10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ~25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute signicantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1< z <2, the CSFRD will be twice as high at the epoch. We are carrying out deep imaging of the NEP eld in 5 broad bands (g; r; i; z; and y) using Hyper Suprime-Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate mid- IR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.