The development of an egg-soaking method for delivering dsRNAs into spider mites.

Recently, the first sprayable RNAi biopesticide, Ledprona, against the Colorado potato beetle, Leptinotarsa decemlineata, has been registered at the United States Environmental Protection Agency. Spider mites (Acari: Tetranychidae), a group of destructive agricultural and horticultural pests, are notorious for rapid development of insecticide/acaricide resistance. The management options, on the other hand, are extremely limited. RNAi-based biopesticides offer a promising control alternative to address this emerging issue. In this study, we i) developed an egg-soaking dsRNA delivery method; ii) evaluated the factors influencing RNAi efficiency, and finally iii) investigated the potential mode of entry of this newly developed egg-soaking RNAi method. In comparison to other dsRNA delivery methods, egg-soaking method was the most efficient, convenient/practical, and cost-effective method for delivering dsRNAs into spider mites. RNAi efficiency of this RNAi method was affected by target genes, dsRNA concentration, developmental stages, and mite species. In general, the hawthorn spider mite, Amphitetranychus viennensis, is more sensitive to RNAi than the two-spotted spider mite, Tetranychus urticae, and both of them have dose-dependent RNAi effect. For different life stages, egg and larvae are the most sensitive life stages to dsRNAs. For different target genes, there is no apparent association between the suppression level and the resultant phenotype. Finally, we demonstrated that this egg-soaking RNAi method acts as both stomach and contact toxicity. Our combined results demonstrate the effectiveness of a topically applied dsRNA delivery method, and the potential of a spray induced gene silencing (SIGS) method as a control alternative for spider mites.

Analysis of Differentially Expressed Genes of Chrysoperla sinica Related to Flight Capacity by Transcriptome.

The lacewing Chrysoperla sinica (Tjeder) is a common natural enemy of many insect pests in China and is frequently employed for biological control programs. Adults make migratory flights after emergence, which reduces their effectiveness as biological control agents. Previously, we proved that 2-d-old unmated females exhibited significantly stronger flight ability than 3-d-old ones. Meanwhile, 3-d-old unmated adults flew significantly longer distances than mated ones. In this study, Illumina RNA sequencing was performed to characterize differentially expressed genes (DEGs) between virgin and mated adults of different ages in a single female strain of C. sinica. In total, 713,563,726 clean reads were obtained and de novo assembled into 109,165 unigenes with an average length of 847 bp (N50 of 1,754 bp), among which 4,382 (4.01%) unigenes matched known proteins. Based on these annotations, many putative transcripts were related to C. sinica's flight capacity and muscle structure, energy supply, growth, development, environmental adaptability, and metabolism of nutritional components and bioactive components. In addition, the differential expression of transcripts between different ages and mating status were analyzed, and DEGs participating in flight capacity and muscles were detected, including glutathione hydrolase, NAD-specific glutamate dehydrogenase, aminopeptidase, and acidic amino acid decarboxylase. The DEGs with functions associated with flight capacity and muscles exhibited higher transcript levels for younger (2 d--old) virgins. This comprehensive C. sinica transcriptomic data provide a foundation for a better understanding of the molecular mechanisms underlying the flight capacity to meet the physiological demands of flight muscles in C. sinica.

Distribution, source identification and health risk assessment of PFASs and two PFOS alternatives in groundwater from non-industrial areas.

Little research has been carried out for the per- and polyfluoroalkyl substances (PFASs) in groundwater from non-industrial areas, even though it has been proved that PFASs can transport for long distance. In this study, the concentration profiles and geographical distribution of 14 PFASs, including two alternatives of perfluorooctane sulfonate (PFOS), 6:2 fluorotelomer sulfonate (6:2 FTS) and potassium 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (F-53B), were analyzed in groundwater samples (n = 102) collected from water wells in non-industrial areas. The total concentrations of PFASs (Σ14PFASs) in groundwater samples ranged from 2.69 to 556 ng/L (mean 43.1 ng/L). The detection rates of shorter chain (C4-C9) PFASs were 62.75-100%, higher than those of long chain (> C10) PFASs with detection rates of less than 40%. The source identification using hierarchical cluster analysis and Spearman rank correlation analysis suggested that domestic sewage and atmospheric deposition may contribute significantly to the PFAS occurrence in groundwater in non-industrial areas, while the nearby industrial parks may contribute some, but not at a significant level. Furthermore, the human health risk assessment analysis shows that the health hazards associated with perfluorooctanoic acid (PFOA) and PFOS, two of the main PFAS constituents in groundwater from non-industrial areas, were one or two orders of magnitude higher than those in a previous study, but were unlikely to cause long-term harm to the residents via the drinking water exposure pathway alone.

Energy Utilization and Flight Muscle Development in Chrysoperla sinica (Neuroptera: Chrysopidae) Female Adults: Relationship With Age and Flight Behavior.

We investigated the accumulation of energy substances, dynamics of flight muscle development, changes in energy substances accumulation, and flight muscle structure after flight activities in female adults of the green lacewing Chrysoperla sinica (Tjeder), a common natural enemy of various insect pests in China. Virgin individuals were chosen at 24, 72, and 120 h after eclosion for energy substance determination and flight muscle observation in this study. Individuals with strong flight ability at 72 h after eclosion were selected for tethered flight assays, followed by detection of energy substances, and flight muscle observation. The results showed that virgin female adults had the highest fat content 72 h after eclosion. Sarcomere length and myofibril diameter changed significantly with age, with the lowest at 24 h after eclosion. With an increase in flight distance, the fat and glycogen contents, sarcomere length, and volume fraction of the transverse tubular system (T-system) decreased and myofibril diameters increased. The volume fraction of the mitochondria did not significantly change, but the structure of the mitochondrial membrane was destroyed, inclusions were reduced, and cavities appeared. The reserves of energy substances, especially lipids, are closely related to the flight ability of C. sinica. The observational results of both flight muscle structure and morphology of mitochondria build a strong relationship with flight behavior. This research should help reveal the regulatory mechanism of flight activity of C. sinica.

Surfactants Improving the Wetting Behavior and Adhesion Mechanism of Pesticide Dilution Droplets on Jujube Leaf Surfaces.

Fruit tree leaves have different chemical compositions and diverse wax layer structures that result in different patterns of wetting and pesticide solution spreading on their surface. Fruit development is a time when pests and diseases occur, during which a large number of pesticides are needed. The wetting and diffusion properties of pesticide droplets on fruit tree leaves were relatively poor. To solve this problem, the wetting characteristics of leaf surfaces with different surfactants were studied. The contact angle, surface tension, adhesive tension, adhesion work, and solid-liquid interfacial tension of five surfactant solution droplets on jujube leaf surfaces during fruit growth were studied by the sessile drop method. C12E5 and Triton X-100 have the best wetting effects. Two surfactants were added to a 3% beta-cyfluthrin emulsion in water, and field efficacy tests were carried out on peach fruit moths in a jujube orchard at different dilutions. The control effect is as high as 90%. During the initial stage when the concentration is low, due to the surface roughness of the leaves, the surfactant molecules adsorbed at the gas-liquid and solid-liquid interfaces reach an equilibrium, and the contact angle on the leaf surface changes slightly. With increasing surfactant concentration, the pinning effect in the spatial structure on the leaf surface is overcome by liquid droplets, thereby significantly decreasing the contact angle. When the concentration is further increased, the surfactant molecules form a saturated adsorption layer on the leaf surface. Due to the existence of a precursor water film in the droplets, surfactant molecules on the interface continuously move to the water film on the surface of jujube tree leaves, thus causing interactions between the droplets and the leaves. The conclusion of this study provides theoretical guidance for the wettability and adhesion of pesticides on jujube leaves, so as to achieve the purpose of reducing pesticide use and improving pesticide efficacy.

Target gene selection for RNAi-based biopesticides against the hawthorn spider mite, Amphitetranychus viennensis (Acari: Tetranychidae).

BACKGROUND: Recently, RNA interference (RNAi)-based biopesticide, a species-specific pest control alternative, has been deregulated and commercialized in the US and Canada. The hawthorn spider mite, Amphitetranychus viennensis Zacher, is a major pest for rosaceous plants, which has been controlled primarily by synthetic pesticides. To address the emerging resistance issues in A. viennensis, we initiated a project to develop RNAi-based biopesticides. RESULTS: In this study, we (i) developed a dietary RNAi system for A. viennensis using leaf disc, (ii) assessed the suitability of multiple control genes to distinguish sequence-specific silencing from non-specific effects within this RNAi system, and (iii) screened for the target gene candidates. As a result, ß-Glucuronidase (GUS), an enzyme derived from E. coli and a broadly used reporter for plants is the appropriate control for A. viennensis RNAi, while green fluorescent protein (GFP), is not suitable due to its significantly higher mortality than the other controls. For target gene screening, suppression was confirmed for all the candidates, including two housekeeping genes (Vacuolar-type H + -ATPase subunit A (V-ATPase A) and Glyceraldehyde 3-phosphate dehydrogenase, (GAPDH)), and three genes associated with development (ATP-dependent RNA Helicase DDX3Y (Belle), CREB-binding protein (CBP), and Farnesoic acid O-methyltransferase (FaMet)). Knocking down of V-ATPase A resulted in the highest mortality (~ 90%) and reduced fecundity (over 90%) than other candidates. As for the genes associated with development, suppression of Belle and CBP, led to approximately 65% mortality, as well as 86% and 40% reduction in fecundity, respectively. Silencing of FaMet, however, had negligible biological impacts on A. viennensis. CONCLUSION: The combined efforts not only establish an effective dsRNA delivery method, but also provide potential target genes for RNAi-based biopesticides against A. viennensis, a devastating invasive pest for fruit trees and woody ornamental plants throughout Asia and Europe. © 2023 Society of Chemical Industry.

The complete mitochondrial genome of the rice moth, Corcyra cephalonica.

The complete mitochondrial genome (mitogenome) of the rice moth, Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) was determined as a circular molecular of 15,273 bp in size. The mitogenome composition (37 genes) and gene order are the same as the other lepidopterans. Nucleotide composition of the C. cephalonica mitogenome is highly A+T biased (80.43%) like other insects. Twelve protein-coding genes start with a typical ATN codon, with the exception of coxl gene, which uses CGA as the initial codon. Nine protein-coding genes have the common stop codon TAA, and the nad2, cox1, cox2, and nad4 have single T as the incomplete stop codon. 22 tRNA genes demonstrated cloverleaf secondary structure. The mitogenome has several large intergenic spacer regions, the spacer1 between trnQ gene and nad2 gene, which is common in Lepidoptera. The spacer 3 between trnE and trnF includes microsatellite-like repeat regions (AT)18 and (TTAT)(3). The spacer 4 (16 bp) between trnS2 gene and nad1 gene has a motif ATACTAT; another species, Sesamia inferens encodes ATCATAT at the same position, while other lepidopteran insects encode a similar ATACTAA motif. The spacer 6 is A+T rich region, include motif ATAGA and a 20-bp poly(T) stretch and two microsatellite (AT)(9), (AT)(8) elements.

Effects of Imidacloprid Applied Alone or in Combination With Organosilicone Surfactants on Biological Traits and Predatory Feeding of Chrysoperla nipponensis (Neuroptera: Chrysopidae).

Organosilicone adjuvants are widely used to increase insecticide application on targeted surfaces. In this work, our aim was to investigate side effects of imidacloprid treatment, either applied alone or in combination with organosilicone compounds, against Chrysoperla nipponensis, an important predator of aphids. Four types of organosilicones were mixed with imidacloprid at different concentrations. The toxicity of the mixture to C. nipponensis was measured under laboratory conditions. The LC50 and LC30 of imidacloprid applied alone and in combination with 0.05% organosilicone were determined. Imidacloprid (LC30) applied alone or in combination with 0.05% organosilicone was used to treat second instar larvae of C. nipponensis; thereafter, its effects on the growth, development, longevity, reproduction, and predatory ability of C. nipponensis were evaluated The results demonstrated that the organosilicone Silwet L-77 reduced the LC50 and LC30 of imidacloprid to 6.09 (95% CI: 2.31-9.42) and 10.95 mg/L (95% CI: 8.16-13.63), respectively, and enhanced imidacloprid toxicity to C. nipponensis, as reflected by the resulting extension of the growth and developmental period, reduction in female longevity, and inhibition of reproduction. When applied alone or in combination with an organosilicone, imidacloprid reduced the consumption of Corcyra cephalonica eggs by C. nipponensis. The functional response of C. nipponensis treated with imidacloprid alone or in combination with organosilicone was type II. Concomitantly, the attack rate was reduced and the handling time of prey increased.

Complete mitochondrial genome of Dioryctria yiai (Lepidoptera: Pyralidae).

The Dioryctria yiai belongs to Pyralidae in Lepidoptera. The complete mitogenome of D. yiai was described in this study, which is typical circular duplex molecules and 15,430 bp in length, containing the standard metazoan set of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and an A + T-rich region. The gene order is same with other lepidopterans. Except for cox1 started with CGA, all other PCGs started with the standard ATN codons. Most of the PCGs terminated with the stop codon TAA, whereas cox2 has the incomplete stop codon T. The phylogenetic tree showed that D. yiai and other six species belong to Phycitinae, are clustered into a clade.

Complete mitochondrial genome of Mycalesis intermedia (Lepidoptera: Nymphalidae).

The Mycalesis intermedia belongs to Nymphalidae in Lepidoptera. We described the complete mitogenome of M. intermedia, which is typical circular duplex molecules and 15,386 bp in length, containing the standard metazoan set of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and an A + T-rich region with macro-repeat sequences. All the inferred tRNA secondary structures show the common cloverleaf pattern, with the exception of trnS1(AGN) which lacks the DHU arm. The M. intermedia mitochondrial genome has the same gene order with other lepidopterans.

Selection of Reference Genes for RT-qPCR Analysis Under Extrinsic Conditions in the Hawthorn Spider Mite, Amphitetranychus viennensis.

Hawthorn spider mite, Amphitetranychus viennensis Zacher, is an economically important arthropod pest for fruit trees and woody ornamental plants. Extensive and repetitive use of synthetic acaricides has led to the development of resistance in A. viennensis. To understand the molecular basis of pesticide resistance, and to develop genetic-based control alternatives (e.g., RNAi-based biopesticides), a standardized protocol for real-time quantitative reverse transcription PCR (RT-qPCR) is needed. In the proceeding phase of this research, we screened for the internal references for RT-qPCR analysis from a pool of A. viennensis housekeeping genes under the intrinsic conditions, including developmental stage, sex, and diapause. Here, we continued our efforts to search for the reference genes under an array of extrinsic conditions, including temperature, humidity, photoperiod, host plant, and dietary RNAi. The stability of these candidate reference genes was investigated using geNorm, NormFinder, BestKeeper, and ΔCt method, respectively. Finally, RefFinder, a statistical platform integrating all four algorisms, provided a comprehensive list of genes for each extrinsic condition: (1) EF1A, α-tubulin and Actin3 were the best candidates for temperature, (2) GAPDH, 18S, and Actin3 were the most stable genes for humidity, (3) V-ATPase B, Actin3, and 18S were the top reference genes for photoperiod, (4) GAPDH, V-ATPase B, and α-tubulin were recommended for host plants, and (5) GAPDH, V-ATPase B, and RPS9 were the top choices for dietary RNAi. Overall, V-ATPase B, GAPDH, and Actin3 were the most commonly selected reference genes in A. viennensis regardless of the experimental conditions, including both intrinsic and extrinsic. Information present here lays the foundation for the genomic and functional genomic research in A. viennensis.

Wetting and adhesion behavior on apple tree leaf surface by adding different surfactants.

OBJECTIVE: This study was conducted to investigate the wetting behavior of different surfactant solutions on the leaf surfaces of apple during the fruit formation stage. METHODS: Five surfactants, including C12E5, Tween-20, Triton X-100, DTAB, and SDS were evaluated in this study. The contact angle, surface tension, adhesion tension, work of adhesion, and solid-liquid interface tension of droplets on the leaf surface were determined by the drop method. RESULTS: The results showed that the nonionic surfactants C12E5 and Triton X-100 had better wetting effects than other surfactants. Moreover, when the concentration of C12E5 and Triton X-100 was 1 × 10-3 mol/L, the leaves reached a completely wet state. Toxicity measurement showed that the incubation rate of Carposina niponensis eggs decreased gradually with increasing content of C12E5 or Triton X-100. Additionally, field efficacy analysis showed that adding C12E5 or Triton X-100 significantly improved the beta-cyfluthrin 3% water emulsion (EW) against C. niponensis. CONCLUSIONS: These results indicate that the surfactants C12E5 and Triton X-100 can significantly improve pesticide application, which will be helpful for reducing pesticide use and developing new pesticides.

Effects of sulfur dioxide on expressions of p53, bax and bcl-2 in lungs of asthmatic rats.

Inhibition of cell apoptosis is an increasingly important factor in modulating airway inflammation in asthma, which is related to environmental pollutants. To investigate the effects of sulfur dioxide (SO(2)) on the mRNA and protein expressions of apoptosis-related genes in lungs from asthmatic rats, male Wistar rats were challenged by ovalbumin (OVA) or SO(2) (2 ppm) inhalation alone or together. Examinations were performed 24 h after the last treatment. The mRNA and protein levels of p53, bax, and bcl-2 were analyzed in lungs using real-time reverse transcription-polymerase chain reaction (RT-PCR) assay and Western blot analysis, respectively. The results indicated that increases of bcl-2 or decreases of p53 and bax mRNA and protein levels were not significant in lungs of rats exposed to SO(2) alone, compared with controls, but elevated or reduced levels of these genes appeared in lungs of asthmatic rats exposed to SO(2) plus OVA, compared with controls, suggesting that SO(2) exposure could result in OVA-induced increases or decreases of transcription and translation levels of these apoptosis-related genes in rat lungs, and may have relations to airway inflammation in asthma. The regulation mechanism of apoptosis in asthma disease exposure to SO(2) needs further study.

Selection of Reference Genes for RT-qPCR Analysis Under Intrinsic Conditions in the Hawthorn Spider Mite, Amphitetranychus viennensis (Acarina: Tetranychidae).

Hawthorn spider mite, Amphitetranychus viennensis Zacher, is one of the most devastating pests of deciduous fruit trees. The overall goal of this research is to develop a standardized protocol for real-time quantitative reverse transcription PCR (RT-qPCR) analysis in A. viennensis following the MIQE (minimum information for publication of Quantitative real time PCR experiments) guidelines. Based on the previous knowledge, we hypothesized that internal references for RT-qPCR analysis reside in housekeeping genes (HKGs). To test this hypothesis, we examined the stability of nine HKGs from A. viennensis, including 18S ribosomal RNA (18S), 28S ribosomal RNA (28S), Elongation factor 1-alpha (EF1A), Actin3, V-ATP vacuolar-type H+-ATPase (V-ATPase), α-tubulin (α-tubulin), Ribosomal protein L13 (RPL13), 40S ribosomal protein S9 (RPS9), and Glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The expression profile of these candidates under intrinsic conditions was evaluated by a panel of computational programs, including geNorm, Normfinder, BestKeeper, and ΔCt method. Based on RefFinder, a comprehensive software integrating all four above-mentioned algorithms, V-ATPase, Actin3, and GAPDH are the top three reference genes, which are stably expressed across all the intrinsic conditions, including developmental stage, sex, and diapause. In addition, we compared reference genes recommended for different developmental stages among the nine cell-content feeding arthropods, including four spider mites, A. viennensis, Tetranychus urticae, Tetranychus cinnabarinus, and Panonychus citri, and five hemipterans, Myzus persicae, Aphis gossypii, Toxoptera citricida, Lipaphis erysimi, and Sogatella furcifera. Not surprisingly, rRNAs and ribosomal proteins, the most abundant RNA species, is the top choice, and follows by EF1A, Actin, GAPDH, and tubulin. Information present here lays the foundation for the genomic and functional genomic research in cell-content feeding arthropods in general and A. viennensis in particular.

Wettability of pear leaves from three regions characterized at different stages after flowering using the OWRK method.

BACKGROUND: A better understanding of leaf surface wettability is critical to improve the adhesion of liquid pesticides. Leaf surface wettability is dependent on the property of the liquid as well as the physical and chemical properties of the leaf, which vary with climate and growth stage. The aim of this study was to characterize the wettability of pear leaves from three different climatic regions at different stages after flowering. RESULTS: The contact angles of different test liquids were measured on both adaxial and abaxial pear leaf surfaces and the Owens-Wendt-Rabel-Kaelble (OWRK) method was used to calculate surface free energy (SFE) and its polar and non-polar components. The results demonstrated that the SFE of both the adaxial and abaxial surface of the pear leaf, and the proportion of polar component, increased with increasing time after flowering. At early growth stages, pear leaves were highly hydrophobic, similar to a polytetrafluoroethylene surface, whereas at later growth stages, pear leaves were hydrophobic, more similar to a polymethylmethacrylate surface. Also, the SFE differed with climatic region. Factors influencing these changes are discussed. CONCLUSION: Changes in contact angles and SFE correlated with the change of the leaf surface wettability. Leaves became easier to wet (higher SFE), with an overall increasing polar component to the surface, with increasing age after flowering. As expected, changes in wettability were found in pear leaves at different stages after flowering and in different regions (P < 0.05). Pear leaves from Yuanping were easier to wet than leaves from Yuci and Linyi, and adaxial surfaces were easier to wet than abaxial surfaces. These results provide beneficial information for the application of agrochemicals for improved wetting and spreading behavior. © 2018 Society of Chemical Industry.

Protein oxidation and DNA-protein crosslink induced by sulfur dioxide in lungs, livers, and hearts from mice.

In this article, protein oxidative damage and DNA-protein crosslinks (DPC) induced by sulfur dioxide (SO(2)) in lungs, livers, and hearts of mice were studied. The protein carbonyl (PCO) content was measured using spectrophotometric DNPH assay to reflect the degree of protein oxidative damage, and the DPC coefficient was measured by using a KCl-sodium dodecyl sulfate (SDS) assay to show the degree of DNA damage in lungs, livers, and hearts from mice exposed to SO(2) at various concentrations (0, 14, 28, and 56 mg-m(- 3)) for 6 h per day for 7 days. The results indicate that SO(2) caused an increase of PCO and DPC level in all organs tested from mice in a concentration-dependent manner. The concentration-response relationships in all organs tested of both female and male mice could be fitted well with monolinear regression equations. The adjusted coefficient R squared of all equations is more than 0.9. These results lead to a conclusion that SO(2) may cause an increase of protein oxidation damage and DNA-protein crosslinking in lungs, livers, and hearts from mice. The rank order of absolute increase in PCO contents and DPC coefficient in three organs from mice compared with controls was lung > liver > heart. Our results also indicated the regulation of PCO and that of DPC induced by SO(2) were conformed to each other; this implies that the protein oxidative damage may be associated with the emergence of DPC.

20-Hydroxyecdysone activates PGRP-SA mediated immune response in Locusta migratoria.

20-hydroxyecdysone (20E) has been implicated in regulating the immune response in insects. Conflicting conclusions on 20E regulating immunity have been reported in model holometabolous species. However, in hemimetabolous insects, the role of 20E as an immune-suppressor or activator and the mechanism remains unclear. The migratory locust Locusta migratoria is a representative member of hemimetabolous insects. Here, digital gene expression (DGE) profiles of Locusta migratoria treated with 20E were analyzed. Pattern recognition receptors [peptidoglycan recognition protein (PGRP-SA), PGRP-LE, and gram-negative binding protein (GNBP3)] and antimicrobial peptides (defensin, diptericin, and i-type lysozyme) were significantly induced by 20E in fat body. These immune-related genes significantly increased their mRNA levels during the high-20E stage. Antibacterial activities in plasma were enhanced after 20E injection and during the high-20E developmental stage. Conversely, when 20E signal was suppressed by RNAi of EcR (ecdysone receptor), the expression levels of these genes and antibacterial activities failed to be increased by 20E injection and during the high-20E developmental stage, and the mortality increased after being infected by entomogenous fungus. The knockdown of PGRP-SA inhibited the expression level of defensin, diptericin and i-type lysozyme in fat body and reduced antibacterial activities in plasma. 20E injection could not significantly induce the expression of antimicrobial peptides after RNAi of PGRP-SA. These results demonstrated that 20E enhanced the immune response by activating PGRP-SA in L. migratoria.

Morphological and ultrastructural characterization of Carposina sasakii larvae (Lepidoptera: Carposinidae) infected by Beauveria bassiana (Ascomycota: Hypocreales: Clavicipitaceae).

The aim of this study was to better understand the pathogenesis of the entomopathogenic fungus Beauveria bassiana (Balsamo) strain TST05 observed on the peach fruit moth (Carposina sasakii (Matsumura)), an important orchard pest. The morphological and ultrastructural characterization of the mature larvae of C. sasakii infected by B. bassiana was investigated by using light, scanning and transmission electron microscopy. The results of the study show that B. bassiana TST05 infected the host larvae mainly by penetrating the integument. The conidia of the fungus adhere easily to the area around the mouthparts and to the basal area around the acanthae on the thorax and abdomen. Observations of the host's defensive response to the fungal attack indicated that dark spots appeared on the cuticle and that melanization appeared in the hemocoel. After overcoming the host's defense system, the pathogen grew and reproduced primarily in the hemocoel. The infection spread sequentially to the internal tissues, e.g., fat body, muscle, Malpighian tubules, gut and even the silk gland. Ultimately, the larval internal organs and tissues were damaged very extensively. Finally, the fungus emerged through the cuticle of the dead insect and released conidiophores that could act as new pathogens to infect other larvae.

The complete mitochondrial genome of Leucoptera malifoliella Costa (Lepidoptera: Lyonetiidae).

The mitochondrial genome (mitogenome) of Leucoptera malifoliella (=L. scitella) (Lepidoptera: Lyonetiidae) was sequenced. The size was 15,646 bp with gene content and order the same as those of other lepidopterans. The nucleotide composition of L. malifoliella mitogenome is highly A+T biased (82.57%), ranked just below Coreana raphaelis (82.66%) (Lepidoptera: Lycaenidae). All protein-coding genes (PCGs) start with the typical ATN codon except for the cox1 gene, which uses CGA as the initiation codon. Nine PCGs have the common stop codon TAA, four PCGs have the common stop codon T as incomplete stop codons, and nad4l and nad6 have TAG as the stop codon. Cloverleaf secondary structures were inferred for 22 tRNA genes, but trnS1(AGN) was found to lack the DHU stem. The secondary structure of rrnL and rrnS is generally similar to other lepidopterans but with some minor differences. The A+T-rich region includes the motif ATAGA, but the poly (T) stretch is replaced by a stem-loop structure, which may have a similar function to the poly (T) stretch. Finally, there are three long repeat (154 bp) sequences followed by one short repeat (56 bp) with four (TA)(n) intervals, and a 10-bp poly-A is present upstream of trnM. Phylogenetic analysis shows that the position of Yponomeutoidea, as represented by L. malifoliella, is the same as traditional classifications. Yponomeutoidea is the sister to the other lepidopteran superfamilies covered in the present study.

[Estimation of bioconcentration factor of benzene derivatives].

To estimate the bioconcentration factor (BCF) of benzene derivatives in fish by gas chromatography retention time (t(R)), this paper measured the BCF of chlorobenzene, o-chloro-toluene, p-dichlorobenzene, m-dichlorobenzene, 1,2-dichlorobenzene, nitrobenzene, p-chloro-aniline, p-chloro-nitrobenzene, and 4-chlorodiphenyl in grass crap, and the t(R) of test derivatives on the stationary phases of six kinds polarity. The monodic regression equation (Type I Eq.) of BCF and t(R) and the binary regression equation (Type II Eq.) of BCF, t(R) and 1X(V) were established, and the statistical test showed that there was a significant correlation between BCF and t(R), and the average correlation coefficients on stationary phases of six kinds polarity were 0.952 and 0.965, respectively. The regression equations could be used to estimate the BCF of the benzene derivatives in grass crap, and the results were not affected by the polarity of stationary phases.