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The world population is projected to reach a staggering 9.8 billion people by the year 2050, placing pressure on our already precarious food security. The need to raise more livestock is unavoidable. The black soldier fly (Hermetia illucens) feeds on a variety of organic wastes. Therefore, H. illucens larvae have already been used as a partial substitute for fishmeal. In contrast, the use of antibiotics in livestock feed as a growth promoter and prophylaxis is endangering global health due to the threat of antimicrobial resistance. Therefore, efforts are underway to find natural substances that can act as substitutes for antibiotics with similar weight gain effects. Insect antimicrobial peptides are defense molecules with distinct structural traits that enable permeation and disruption of target membranes. Here, we investigated various methods for stimulating synthesis of AMPs in H. illucens larvae. The activation of innate immune response pathways leading to the production of various types of AMPs upon thermal injury was also investigated. Although not using bacteria, the thermal treatment to elicit expression of AMP genes was similar to the infection by Gram-positive bacteria. Our findings might prove beneficial in the industrial use of black soldier flies to maintain livestock and improve environmental health.

Background: The dung beetle Phelotrupes auratus is a holometabolous insect belonging to the order Coleoptera, and it is widely distributed in Japan. The P. auratus habitat depends on host herbivore animals. P. auratus eats the dung of the host herbivores and carries it underground for its young. In this process, herbivore droppings disappear from the ground, not only keeping the ground hygienic but also maintaining good soil conditions for plant growth. In this way, a rich ecosystem is maintained. In recent years, the population of P. auratus has decreased, and the main cause has been the decrease in grazing land. It seems that Japanese dung beetles are mainly dependent on herbivores for nutrient sources. However, the physiological relationship between host herbivores and P. auratus has not been well investigated. Here, we investigated the nutritional metabolism system of P. auratus by performing whole gene expression analysis of individuals collected from two areas where the ecosystem is occupied by different specific herbivores.Results: We obtained 209,123 transcripts from P. auratus from Nara Park and Cape Toi and identified 2,592 differentially expressed genes in the fat bodies of the Nara Park and Cape Toi groups. We annotated P. auratus transcripts using Homo sapiens and Drosophila melanogaster genes as references; 36.6% of P. auratus transcripts were assigned to H. sapiens genes, and 24.7% of P. auratus transcripts were assigned to D. melanogaster genes. Therefore, we chose H. sapiens genes for P. auratus transcript annotation. Principal component analysis and gene set enrichment analysis revealed that the nutritional metabolism of P. auratus from Cape Toi might differ from that of P. auratus from Nara Park.Conclusion: We analyzed the nutritional metabolism system of P. auratus from Cape Toi and Nara Park and found that the characteristics of the nutritional metabolism process might depend on the plants consumed by the host herbivore. Our findings will contribute to elucidating the relationships among habitat plants, herbivores, and dung decomposers and may aid in the maintenance of sustainable land health cycles.

Phytophagous insect larvae feed on plants containing secondary metabolic products with biological activity against other predatory organisms. Phytophagous insects can use their specialised metabolic systems to covert these secondary metabolic products into compounds with therapeutic properties useful to mankind. Some Asians drink tea decoctions made from phytophagous insect frass which is believed to be effective against inflammatory diseases. However, insects that can convert plant-derived secondary metabolic products into useful human therapeutic agents remain poorly studied. Here, we constructed the TUATinsecta database by integrating publicly plant/insect datasets for the purpose of selecting insect species. Using TUAT-insecta we selected the Asian swallowtail butterfly, Papilio xuthus larvae fed on several species of Rutaceous plants and examined whether the plant-derived secondary metabolites, especially those present in frass, were chemically altered or not. We extracted metabolic products from frass using three organic solvents with different polarities, and evaluated solvent fractions for their cytotoxic effects against several human cell lines. We found that chloroform frass extracts from P. xuthus larvae fed on Poncirus trifoliata leaves contained significant cytotoxic activity. Our findings demonstrate that screening of insect species using the ‘TUATinsecta’ database provides an important pipeline for discovering novel therapeutic agents that might be useful for mankind.

This letter proposes a routing framework for heterogeneous multi-robot teams in exploration tasks. The proposed framework deals with a combinatorial optimization problem, and provides a new solving algorithm, for Generalized Team Orienteering Problem (GTOP). In this letter, a route optimization problem is formulated for a heterogeneous multi-robot system. A novel problem solver is also proposed based on self-organizing map. The proposed framework has a strong advantage in its scalability because the processing time is independent from the number of robots, and the heterogeneity of the team. The validity of the proposed framework is evaluated in the exploration, and mapping tasks by heterogeneous robot team with overlapping abilities. The simulation results show the effectiveness of the proposed framework, and how it outperforms the conventional greedy exploration scheme.

The body form of holometabolous insects dramatically transforms from larval to adult stages during the pupal developmental stage. In motoneuron "remodelling," larval neuronal cells degenerate and reconnect to new adult muscles. However, the factor that controls location-specific neuronal remodelling has not yet been elucidated. Here, we show that an antioxidant enzyme, Tribolium castaneum superoxide dismutase 6 (TcSOD6), is secreted into the haemolymph and controls the remodelling of adult neuronal cells during metamorphosis. TcSOD6 has a unique domain architecture and is mainly expressed in the pupal developmental stage. The knockdown of TcSOD6 expression in the pupa inhibits axon formation, suggesting a need for SOD activity in neuronal remodelling. Therefore, we conclude that TcSOD6 plays a role in neuronal remodelling during metamorphosis, providing new insights into the evolution of SOD functions.

Objective Insects are the most evolutionarily successful groups of organisms, and this success is largely due to their flight ability. Interestingly, some stick insects have lost their flight ability despite having wings. To elucidate the shift from wingless to flying forms during insect evolution, we compared the nutritional metabolism system among flight-winged, flightless-winged, and flightless-wingless stick insect groups. Results Here, we report RNA sequencing of midgut transcriptome of Entoria okinawaensis, a prominent Japanese flightless-wingless stick insect, and the comparative analysis of its transcriptome in publicly available midgut transcriptomes obtained from seven stick insect species. A gene enrichment analysis for differentially expressed genes, including those obtained from winged vs wingless and flight vs flightless genes comparisons, revealed that carbohydrate metabolic process-related genes were highly expressed in the winged stick insect group. We also found that the expression of the mitochondrial enolase superfamily member 1 transcript was significantly higher in the winged stick insect group than in the wingless stick insect group. Our findings could indicate that carbohydrate metabolic processes are related to the evolutionary process through which stick insects gain the ability of flight.

Temperature is one of the most influential factors for animals. The acclimation (rearing) and challenge temperatures are often more important than the given temperature per se. These effects on physiological responses have been known, but not well understood on immune responses. Here, we investigated the integrated effects of rearing and challenge temperatures on haemocyte populations in larvae of a plusiine moth, Chrysodeixis eriosoma. We hypothesize that the haemocyte concentration is decreased (increased) at higher (lower) temperatures from rearing temperatures and that the proportions of haemocyte types exhibit directional changes at higher (lower) temperatures to compensate for immune reactions. We expect that increasing (decreasing) the challenge temperature from the rearing temperature enhances (reduces) phagocytic activity. We found that higher temperatures slightly decreased the haemocyte concentration. We detected small changes in the proportions of haemocyte types among rearing temperatures, but the changes were non‐directional and most of them were statistically insignificant. We also found the integrated effects only with increases in the challenge temperatures, which resulted in increased phagocytosis, whereas no apparent reactions were detected with decreases in the challenge temperatures. Our results show that the haemocyte concentration is significantly affected by the rearing temperature, which implies that haematopoiesis depends on the ambient temperature.We discuss some adaptive and non‐adaptive components for the positive integrated effects of increases in the challenge temperatures. We also discussed the obtained non‐responsiveness in the integrated effects with decreases in the challenge temperatures., Physiological Entomology, Article in Press.

BackgroundPolyembryony is defined as the formation of several embryos from a single egg. This phenomenon can occur in humans, armadillo, and some endoparasitoid insects. However, the mechanism underlying polyembryogenesis in animals remains to be elucidated. The polyembryonic parasitoid waspCopidosoma floridanumoviposits its egg into an egg of the host insect; eventually, over 2000 individuals will arise from one egg. Previously, we reported that polyembryogenesis is enhanced when the juvenile hormone (JH) added to the culture medium in the embryo culture. Hence, in the present study, we performed RNA sequencing (RNA-Seq) analysis to investigate the molecular mechanisms controlling polyembryogenesis ofC. floridanum. Functional annotation of genes is not fully available forC.floridanum; however, whole genome assembly has been archived. Hence, we constructed a pipeline for gene functional annotation inC. floridanumand performed molecular network analysis. We analyzed differentially expressed genes between control and JH-treated molura after 48 h of culture, then used the tblastx program to assign wholeC. floridanumtranscripts to human gene.ResultsWe obtained 11,117 transcripts in the JH treatment group and identified 217 differentially expressed genes compared with the control group. As a result, 76% ofC. floridanumtranscripts were assigned to human genes. Gene enrichment analysis revealed genes associated with platelet degranulation, fatty acid biosynthesis, cell morphogenesis in the differentiation and integrin signaling pathways were fluctuated following JH treatment. Furthermore, Cytoscape analysis revealed a molecular interaction that was possibly associated with polyembryogenesis .ConclusionsWe have constructed a pipeline for gene functional annotation ofC. floridanum, and identified transcripts with high similarity to human genes during early embryo developmental. Additionally, this study reveals new molecular interactions associated with polyembryogenesis; these interactions could indicate the molecular mechanisms underlying polyembryony. Our results highlight the potential utility of molecular interaction analysis in human twins.

BACKGROUND: Acting against the development of resistance to antibiotics and insecticides, involving negatively correlated cross-resistance (NCR) is an alternative to use- and-discard approach. It is termed NCR that toxic chemicals interact with each other and resistance of target organisms to one chemical is sometimes associated with increased susceptibility to a second chemical when; an allele confers resistance to one toxic chemical and hyper-susceptibility to another, NCR occurs. However, only 11 toxin pairs have been revealed to cause NCR in insects. Finding novel NCRs is needed for integrated pest management. RESULTS: We analyzed permethrin, an insecticide, induced transcriptomes of cultured fat bodies of the silkworm Bombyx mori, a lepidopteran model insect. Differentially expressed gene analyses suggested Bacillus thuringiensis (Bt) toxin was an NCR toxin of permethrin. NCR to permethrin and Bt toxins in Thysanoplusia intermixta, the agricultural pest moth, was examined; the children of permethrin survivor T. intermixta had increased susceptibility to Bt toxin. CONCLUSIONS: A novel NCR toxin pair, permethrin and Bt toxin, was discovered. The screening and developmental method for negatively correlated cross-resistance toxins established in this study was effective, in vitro screening using model organisms and in vivo verification using agricultural pests.

Copidosoma floridanum is a polyembryonic, caste-forming, wasp species. The ratio of investment in different castes changes with environmental stressors (e.g. multi-parasitism with competitors). The vasa gene was first identified in Drosophila melanogaster as a germ-cell-determining factor, and C. floridanum vasa (Cf-vas) gene positive cells have been known to develop into reproductive larvae. Cf-vas seems to control the ratio of investment in C. floridanum larval castes. In this study, we identified environmental factors that control Cf-vas mRNA expression in Japanese C. floridanum by examining Cf-vas mRNA expression under competitor (Meteorus pulchricornis) venom stress; we treated the male and female morulae with M. pulchricornis venom. We also assessed the effects of multi-parasitism of Japanese C. floridanum with M. pulchricornis and found an increasing number of female soldier larvae. The results showed that several amino acid sequences differ between the Japanese and US Cf-vas. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) showed that Japanese Cf-vas mRNA is expressed in both male and female larvae and pupae, but mRNA expression decreases in adults. Cf-vas mRNA expression significantly decreased, while C. floridanum dronc (Cf-dronc) mRNA expression increased, in female morulae after M. pulchricornis venom treatment at 20 h and 0 h of the culture period, respectively. Females and males showed different Cf-vas or Cf-dronc mRNA expression after M. pulchricornis venom treatment. Therefore, M. pulchricornis venom could affect the ratio of investment in different female castes of Japanese C. floridanum by decreasing Cf-vas mRNA expression via apoptosis.

Self-sacrifice is very rare among organisms. Here, we report a new and astonishing case of adaptive self-sacrifice in a polyembryonic parasitic wasp, Copidosoma floridanum. This wasp is unique in terms of its larval cloning and soldier larvae. Male clone larvae have been found to be killed by female soldier larvae, which suggests intersexual conflict between male and female larvae. However, we show here that mass killing is adaptive to all the killed males as well as the female soldiers that have conducted the killing because the killing increases their indirect fitness by promoting the reproduction of their clone sibs. We construct a simple model that shows that the optimal number of surviving males for both male and female larvae is very small but not zero. We then compare this prediction with the field data. These data agree quite well with the model predictions, showing an optimal killing rate of approximately 94–98% of the males in a mixed brood. The underlying mechanism of this mass kill is almost identical to the local competition for mates that occurs in other wasp species. The maternal control of the sex ratio during oviposition, which is well known in other hymenopterans, is impossible in this polyembryonic wasp. Thus, this mass kill is necessary to maximize the fitness of the female killers and male victims, which can be seen as an analogy of programmed cell death in multicellular organisms.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Insects are well adapted to changing environmental conditions. They have unique systems for eliminating reactive oxygen species (ROS). Superoxide dismutase (SOD) is a key enzyme that plays a primary role in removing ROS. Bombyx mori is a lepidopteran insect, whose body size is larger than the model insect Drosophila melanogaster, which enabled us to more easily examine gene expression at the tissue level. We searched B. mori SOD (BmSOD) genes using genome database, and we analyzed their function under different type of oxidative stress. Consequently, we identified four new types of BmSODs in addition to the three types already known. Two of the seven types had a unique domain architecture that has not been discovered previously in the SOD family, and they were expressed in different tissues and developmental stages. Furthermore, these BmSODs responded differently to several kinds of stressors. Our results showed that the seven types of BmSODs are likely to play different roles in B. mori; therefore, B. mori could be used to distinguish the functions of each SOD for resistance to oxidative stress that changes with the environmental conditions.

The crystal structure and electronic properties of Ag{sub x}VP{sub 2}O{sub 7} with a wide composition range of 0.7≤x≤1 synthesized newly are explored through measurements of X-ray four-circle diffraction, electrical resistivity, and magnetization. This system is monoclinic with space group P2{sub 1}/c and the lattice constants for x=1 are a=7.3358(3) Å, b=8.0235(3) Å, c=9.5782(5) Å, β=111.940(4)°, and V=522.93(5) Å{sup 3}. The structure is described in terms of VO{sub 6} octahedra which are bridged with P{sub 2}O{sub 7} groups to form a three-dimensional network with the hexagonal tunnels that a pair of Ag ions apparently resides in. The crystal field of V ions is intermediate and the electron configuration has the orbital-singlet ground state with a gap of the order of 10 K to the doublet state. - Graphical abstract: (a) The temperature dependencies of inverse magnetic susceptibilities for Ag{sub x}VP{sub 2}O{sub 7} with x=0.7−1 and (b) the low-temperature susceptibilities. - Highlights: • Ag{sub x}VP{sub 2}O{sub 7} system with 0.7

Dipeptide Gly-Pro, a hard-to-degrade and collagenous peptide, is thought to be hydrolysed by prolidases that can work on various X-Pro dipeptides. Here, we found an entirely different type of dipeptidase from Lactobacillus farciminis JCM1097 that cleaves Gly-Pro far more efficiently and with higher specificity than prolidases, and then investigated its properties by use of a recombinant enzyme. Although L. farciminis dipeptidase was expressed in the form of an inclusion body in Escherichia coli at 37 °C, it was smoothly over-expressed in a soluble form at a lower temperature. The maximal Gly-Pro hydrolytic activity was attained in E. coli at 30 °C. In contrast to prolidases that are metallopeptidases showing the modest or marginal activity toward Gly-Pro, this L. farciminis dipeptidase belongs to the cysteine peptidase family C69. Lactobacillus farciminis dipeptidase occurs in cytoplasm and utilizes the side chain of an amino-terminal cysteine residue to perform the nucleophilic attack on the target amide bond between Gly-Pro after processing eight amino acid residues at the N-terminus. Furthermore, L. farciminis dipeptidase is potent enough to synthesize Gly-Pro from Gly and Pro by a reverse reaction. These novel properties could be revealed by virtue of the success in preparing recombinant enzymes in higher yield and in a stable form.

The slide-ring (SR) gels derived from polyethylene glycol (PEG) threatened with polyrotaxane or hydroxypropyl polyrotaxane and crosslinked by 1,4-butanediol diglycidil ether were swollen with ionic liquids (ILs) and their ionic conduction was investigated. The molar conductivity of an SR gel swollen with 1-ethyl-3-methylimidazolium ethylsulfate (EMIES) with a high swelling ratio and with a small crosslinking density was more than 92% of that of neat IL. With increasing crosslinking density, the swelling ratio and molar conductivity decreased due to increasing disturbance of ion transport by the polymer networks, wherein the hydrodynamic radius of the ionic motion unit was estimated to be 9.7 nm from the relation between the mesh size of SR gels and conductivity. Further, the ionic conduction of SR gels swollen with ILs under compressive deformation was measured. With increasing compressive deformation, the ionic conductivity first increased to a peak at a compression ratio of about 0.75 and then subsequently decreased. This conductivity change can be explained by anisotropic deformation of SR gel networks under compressive deformation.

Defense against enemies is a type of natural selection considered fundamentally equivalent between the sexes. In reality, however, whether males and females differ in defense strategy is unknown. Multiparasitism necessarily leads to the problem of defense for a parasite (parasitoid). The polyembryonic parasitic wasp Copidosoma floridanum is famous for its larval soldiers’ ability to kill other parasites. This wasp also exhibits sexual differences not only with regard to the competitive ability of the soldier caste but also with regard to host immune enhancement. Female soldiers are more aggressive than male soldiers and their numbers increase upon invasion of the host by other parasites. In this report, in vivo and in vitro competition assays were used to test whether females have a toxic humoral factor; if so, then its strength was compared with that of males. We found that females have a toxic factor that is much weaker than that of males. Our results imply sexual complementarity between host humoral toxicity and larval soldiers. We discuss how this sexual complementarity guarantees adaptive advantages for both males and females despite the one-sided killing of male reproductives by larval female soldiers in a mixed-sex brood.

Heavy sea-water spray icing is a major problem in the maintenance of lighthouses situated in northern harbors facing the Sea of Japan. Moreover, low ice adhesion materials or anti-icing coatings are ineffective over long periods. In this study, we have investigated the characteristics of saline ice adhesion on hydrophilic and hydrophobic pliable polymer sheets that can be used to envelop and thereby protect small lighthouses. We conducted experiments in cold room laboratories, and further, we verified the deicing conditions. Ice adhesion strength tests using fresh water indicated that a highly hydrophobic surface exhibited lower adhesion strength than other test materials. The results of saline ice adhesion tests at −20°C indicated that the adhesion strength decreases very rapidly as the salinity increases for all materials; this trend was particularly remarkable in case of superhydrophilic materials. The water spray icing tests were verified by experiments conducted using an ice model basin. Wet...

家畜糞堆肥の窒素の利用性評価を行うためにデタージェント分析を適用し，デタージェント分画における窒素含有率およびC/N比と窒素無機化率の関係を検討した．石川県内の畜産農家，堆肥センターで生産された家畜糞堆肥19点および新鮮糞3点について酸性デタージェント繊維（ADF），中性デタージェント繊維（NDF），中性デタージェントリグニン（NDL），細胞内容物質（OCC : 有機物-NDF）の各分画について窒素含有率およびC/N比を調べた．新鮮糞，堆肥ともにOCC中に含まれる窒素がNDL中，NDF-NDL中よりも多かった．鶏糞中の尿酸のほとんどがADFとして定量されていた．堆肥化によってNDL中の窒素の割合が高くなった．新鮮糞では，乳牛糞と豚糞はNDF中窒素 ＞ ADF中窒素であるが，鶏糞はADF中窒素 ＞ NDF中窒素であった．大部分の堆肥はADF中窒素 ＞ NDF中窒素であった．牛糞堆肥および副資材の多い豚糞堆肥・鶏糞堆肥では，AD処理による窒素除去がND処理に比べ劣っていた．C/N比が高い堆肥でもOCC中C/N比は低く，ほとんどが10以下であった．逆にNDF中C/N比が80近い堆肥もあり，このことから堆肥の全体のC/N比はNDF中C/N比に大きく影響されることがわかった．窒素無機化については，多くの牛糞堆肥は培養初期に一旦窒素を無機化しながら，その後有機化した．競走馬糞堆肥は培養期間中ほとんど窒素無機化率に変化がなかった．未熟な豚糞・鶏糞堆肥は7日間の培養で一旦窒素が有機化し，その後無機化した．副資材が多く含まれ，腐熟が進んだ豚糞・鶏糞堆肥は7，14日までの培養期間中に窒素は無機化するが，その後有機化した．28，60日の培養期間における有機態窒素と無機化率の関係について，NDF中C/N比の相関は高いが，OCC中C/N比の相関は低かった．以上の結果から，ND処理による分画は明確に窒素無機化に関する性質を区分しており，培養初期にはOCC中窒素が，それ以降はNDF中窒素が無機化または有機化していると考えられた．

Polycrystalline samples of AgxVP2O7 (0.7 ≤ x ≤ 0.9) are prepared by solid state reaction of mixtures of composition 2xAg3PO4, 4xVPO4, 3(1-x)VPO5, and (3-x)V(PO3)3 (sealed quartz tubes, 1073 K, 12 h).