Indomethacin and 20-hydroxyecdysone influence protein expression in a Spodoptera frugiperda nervous system cell line.

Insecticide mode of action studies provide insights into how new insecticidal actives function and contribute to assessing safety to humans and nontarget organisms. Insect cell lines that express potential target sites can serve as valuable tools in this effort. In this paper, we report on the influence of two signaling molecules on protein expression in a nervous system cell line established from Spodoptera frugiperda (Bayer/BCIRL-SfNS2-0714-TR). We selected this line because we established it in our laboratory and we are experienced in using it. Cells were exposed to the insect developmental hormone (1 µg/mL 20-hydroxyecdysone, 20E) and/or a cyclooxygenase (COX) inhibitor (25 µM indomethacin, INDO; inhibits prostaglandin [PG] biosynthesis) for 24 h (Day 2), 72 h (Day 4), or 120 h (Day 6). We selected a PG biosynthesis inhibitor because PGs act in many aspects of insect biology, such as embryonic development, immunity, and protein phosphorylation. We selected the developmental hormone, 20E, because it also acts in fundamental aspects of insect biology. We identified specific proteins via in silico analysis. Changes in protein expression levels were determined using liquid chromatography-mass spectrometry (MS) + MS-MS. The largest number of changes in protein expression occurred on Day 2. The combination of 20E plus INDO led to 222 differentially expressed proteins, which documents the deep significance of PGs and 20E in insect biology. 20E and, separately, INDO led to changes in 30 proteins each (p value < 0.01; >2X or <0.5X-fold changes). We recorded changes in the expression of 9 or 12 proteins (20E), 10 or 6 proteins (INDO), and 21 or 20 proteins (20E + INDO) on D4 and D6, respectively. While the cell line was established from neuronal tissue, the differentially expressed proteins act in a variety of fundamental cell processes. In this paper, we moved beyond a list of proteins by providing detailed, Gene Ontology term analyses and enrichment, which offers an in-depth understanding of the influence of these treatments on the SfNS2 cells. Because proteins are active components of cell physiology in their roles as enzymes, receptors, elements of signaling transduction pathways, and cellular structures, changes in their expression levels under the influence of signaling molecules provide insights into their function in insect cell physiology.

The Lethal and Sublethal Effects of Lambda-Cyhalothrin and Emamectin Benzoate on the Soybean Pest Riptortus pedestris (Fabricius).

Riptortus pedestris (Fabricius, 1775) (Hemiptera: Alydidae) is a major soybean pest in East Asia that can cause soybean staygreen syndrome. To date, no insecticides have been registered for the control of R. pedestris in China, and these insects are primarily controlled in the field through the application of broad-spectrum insecticides including lambda-cyhalothrin (LCT) and emamectin benzoate (EMB). Here, the lethal and sublethal effects of LCT and EMB on R. pedestris were comprehensively evaluated. LCT and EMB were both found to exhibit high levels of toxicity and concentration-dependent repellent effects for R. pedestris. The exposure of third instar nymphs from the F0 generation to LC30 concentrations of LCT and EMB resulted in a significant increase in the duration of nymph development and adult pre-oviposition period (APOP), together with reductions in fifth instar nymph and adult body weight, longevity, oviposition days, fecundity, vitellarium length, lateral oviduct diameter, and vitellogenin (Vg) gene expression as compared to control treatment. Strikingly, these suppressive effects were transmitted to the F1 generation, which similarly experienced the prolongation of preadult development and the preoviposition period (TPOP). Relative to control-treated populations, the F1 generation for these insecticide-treated groups also exhibited significant decreases in population parameter values. Overall, these data offer new insight into the impact that LCT and EMB treatment can have on R. pedestris, providing a valuable foundation for the application of these pesticides in the context of integrated pest management strategies aimed at soybean crop preservation.

Identification of highly active compounds from insecticidal plant Oroxylum indicum L. (Vent.) and the induction of apoptosis by lapachol on Sf9 cells.

The extraction of biopesticides from plants has become a promising field for agricultural development. To explore a high-efficiency and viable method for the screening of plant compounds with insecticidal activity, we screened for active ingredients in the insecticidal plant, Oroxylum indicum L. Vent, using Sf9 cells. A CCK-8 cytotoxicity assay kit was used for high-throughput screening of 34 compounds contained in O. indicum. The apoptosis-inducing effect of the highly cytotoxic compound on Sf9 cells was investigated by morphological characterization using inverted microscopy, caspase-3 activity assay, and DNA gel electrophoresis. Finally, the biological activity of compounds against aphids was evaluated using the leaf-pest dipping methods and leaf dipping methods. Results showed that among the main compounds identified, lapachol, chrysin, and baicalein had good proliferation inhibitory effects on Sf9 cells, with their recorded IC50 being 11.53 mg/L, 38.39 mg/L, and 42.10 mg/L, respectively. Moreover, the IC50 value of lapachol was lower than the control insecticides rotenone (18.03 mg/L) and fipronil (21.04 mg/L). Apoptosis assay further showed that lapachol promoted the production of caspase-3 and led to DNA fragmentation in Sf9 cells. Lapachol showed high biological activity against Aphis gossypii, Sitobion avenae, and Semiaphis heraclei, with its recorded LC50 being 104.40, 101.80, and 110.29 mg/L, respectively, which were comparable to the activity of the control insecticide rotenone. High-throughput screening of active ingredients in the insecticidal plant O. indicum using Sf9 cells is feasible, and the identification of lapachol as the main aphidicidal active substance is valuable for further study.

Detoxification enzyme is involved in the temperature effect on the toxicity of tetrachlorantraniliprole to Plutella xylostella.

The efficacy of insecticides is usually influenced by temperature. Insecticides can be divided into "positive", "negative" and "non-effect" temperature coefficient insecticides (TCI). To assess the temperature-dependent effect of tetrachlorantraniliprole (TET) on Plutella xylostella Linnaeus and to elucidate the mechanism of temperature affects TET toxicity, we determined the toxicity of TET against P. xylostella from 15 °C to 35 °C by leaf dipping method. Moreover, we compared the transcriptome data of the third-instar larvae treated by TET, chlorfenapyr (CHL, non-effect TCI), and the control group at 15, 25, 35 °C, respectively. The results showed that the toxicity of TET against P. xylostella increased with increasing temperature from 15 °C to 35 °C. A total of 21 differential expressed genes (DEGs) of detoxification enzymes were screened by RNA-seq, in which 10 up-regulated genes (3 UGTs, 2 GSTs, 5 P450s) may involve the positive temperature effect of TET, and their expression patterns were consistent with qPCR results. Furthermore, the enzyme activities of GSTs and UGTs significantly increased after TET was treated at 15 °C. Especially, the temperature coefficient (TC) of TET was significantly reduced mixed with UGTs enzyme inhibitor 5-NI. Overall, TET showed higher insecticidal activity with increasing temperature, in which detoxifying enzymes associated with regulation of the positive temperature effect of TET on P. xylostella, such as UGTs, GSTs and P450s, are strongly involved. The transcriptome data provide in-depth information to understand the TET mechanism against diamondback moth. Most importantly, we identified detoxification enzymes that might be involved in regulating TET's positive temperature effect process, and contributed to efficient pest management.

Potent insecticidal activity of Eleocharis dulcis (Burm. f.) Trin peel extract and its main components against aphids.

BACKGROUND: Aphids are significant pests of cash crops and food farm crops. Botanical insecticides are safe for aphid control, especially for organic farming. In this study, Eleocharis dulcis (Burm. f.) Trin. peel extract (EDPE), a new botanical insecticide, was investigated for its active compositions against several agricultural aphids. RESULTS: The results showed that the EDPE had high insecticidal activity against Sitobion avenae Fabricius, Aphis gossypii Glover, Megoura crassicauda Mordvilko, and Acyrthosiphon pisum Harris, with half-lethal concentration (LC50 ) values of 95.92, 81.04, 140.31, and 255.73 mg/L after 48 h of treatment. In the pot culture assay, the aphicidal effects of 25% EDPE soluble liquid (SL) at a concentration of 0.016% were 68.98 ± 5.61%, 79.33 ± 8.27%, and 88.82 ± 3.91% after the first, third, and seventh days of treatment, respectively. Nine compounds were identified by bioactivity-directed fractionation: 4',5'-dimethoxy-6,6-dimethylpyranoisoflavone (1), 3-methoxy-4-hydroxylonchocarpin (2), 4-hydroxylonchocarpin (3), 4-methoxylonchocarpin (4), barbigerone (5), lonchocarpusone (6), 6a,12a-dehydrodeguelin (7), 13-homo-13-oxa-6a, 12a-dehydrodeguelin (8) and deguelin (9). Among them, 4-hydroxylonchocarpin (3) showed the highest aphidicidal activity against M. crassicauda, S. avenae, and A. pisum, with LC50 values of 97.24, 140.63, and 112.31 mg/L, respectively. CONCLUSION: These data contribute to a better understanding of the aphicidal activity of EDPE and its main component, 4-hydroxylonchocarpin. This will help to develop new botanical insecticides to contro aphids. © 2022 Society of Chemical Industry.

Design and fabrication of a novel on-chip pressure sensor for microchannels.

Pressure is important in virtually all problems in fluid dynamics from macro-scale to micro/nano-scale flows. Although technologies are well developed for its measurement at the macroscopic scale, pressure quantification at the microscopic scale is still not trivial. This study reports the design and fabrication of an on-chip sensor that enables quantification of pressure in microfluidic devices based on a novel technique called astigmatic particle tracking. With this technique, thin membranes that sense pressure variations in the fluid flow can be characterized conveniently by imaging the shapes of the particles embedded in the membranes. This innovative design only relies on the reflected light from the back of the microchannel, rendering the sensor to be separate and noninvasive to the flow of interest. This sensor was then applied to characterize the pressure drop in single-phase flows with an accuracy of ∼70 Pa and good agreement was achieved between the sensor, a commercial pressure transducer and numerical simulation results. Additionally, the sensor successfully measured the capillary pressure across an air-water interface with a 7% deviation from the theoretical value. To the best of our knowledge, this pore-scale capillary pressure quantification is achieved for the first time using an on-chip pressure sensor of this kind. This study provides a novel method for in situ quantification of local pressure and thus opens the door to a renewed understanding of pore-scale physics of local pressure in multi-phase flow in porous media.

Influence of pre-exposure time on the toxicities of different temperature effect insecticides to Apolygus lucorum (Hemiptera: Miridae).

Temperature can have influences on the toxicities and efficacies of insecticides. Therefore, it is important to accurately evaluate the temperature effect (TE) on the toxicities of insecticides to insects. Previous studies have shown that the pre-exposure of insects to temperatures before their contact with insecticides, caused variations in their toxicities. However, most of these studies focused on the TE of the insecticides post-treatment. In this study we hypothesized that pre-exposure time of insect at different temperature can influence the toxicities of insecticides. We then evaluated the influence of different pre-exposure time (0, 2, 4, 8, 12 and 24 h) on toxicities of three different temperature effect insecticides (TEIs) to Apolygus lucorum at 15, 25 and 35°C respectively. We found that all toxicities of three TEIs to A. lucorum did not vary with pre-exposure time at 25°C. The LC50 of hexaflumuron (positive TEI) only decreased (from 1800.06 to 237.40 mg/L) at 15°C, with an increase in the pre-exposure time. Whereas the LC50 of ß-cypermethrin (negative TEI) decreased from 225.43 to 60.79 mg/L at 35°C. These results also showed that the temperature coefficients (TCs) of the toxicities were influenced by pre-exposure time at different temperatures. For hexaflumuron, all the TCs at 25°C and 35°C decreased, as the pre-exposure time increased. For ß-cypermethrin, the TCs decreased significantly only at 35°C. The toxicity and TCs of phoxim (non-effect TEI) showed no obvious fluctuation at the tested temperatures. These results showed that when the pre-exposure times were extended, the toxicities of the positive / negative TEI showed an increase at the temperature where the pest was less sensitive to the insecticides. These results can be applied to determine the toxicities / bioactivities of different insecticides accurately at different temperatures.

Effect of High Temperature and Natural Enemies on the Interspecies Competition Between Two Wheat Aphid Species, Rhopalosiphum padi and Sitobion miscanthi.

Interspecies competition affects the distribution, quantity, and community structure of insects, especially among closely-related (congeners) species. Some ecological factors differentially affect the fitness of co-existing species, thus conferring an advantage on one competitor, and then the structure of communities. The present work evaluated the effects of high temperature and natural enemies on the interspecific competition between the grain aphid Sitobion miscanthi (Takahashi) (Aphididae: Hemiptera) and bird cherry-oat aphid Rhopalosiphum padi (L.) (Hemiptera: Aphididae), two key pests of wheat in China. Results showed that the population growth of R. padi was faster at 30°C, and the intrinsic rate of natural increase (rm) value was 5 times that of S. miscanthi, indicating that R. padi was more high-temperature resistant and has advantages in interspecific competition at high temperature. Moreover, compared to S. miscanthi, the population of R. padi was less affected by their predator, larvae of the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), and aphid parasitoids, Aphidius avenae (Haliday) or Aphidius gifuensis (Ashmead) (Hymenoptera: Aphidiidae), which made them gain an advantage in the interspecific competition. Our results enrich the knowledge of phytophagous insect interspecific completion and implicate the ecological mechanism of R. padi may become the dominant species in wheat fields in China.

Prostaglandin A2 induces apoptosis in three cell lines derived from the fall armyworm, Spodoptera frugiperda.

Animals maintain homeostasis of cell numbers, constantly creating new cells and eliminating others. Programmed cell death, apoptosis, is a mechanism of cell elimination and it acts in many aspects of animal biology. Drawing on the biomedical background, several signals launch the apoptosis mechanisms, including prostaglandins (PGs). Based on this information, we posed the hypothesis that PGs similarly induce apoptosis in insect cell lines. We used three Spodoptera frugiperda cell lines, including two newly established, BCIRL-SfNS-0518B-YL derived from the central nervous system and BCIRL-Sf4FB-0614-SGS derived from fat body, and the commercially available Sf9 cells. Using a kinetic apoptosis kit, we found treating SfNS cells for 18 h with 15 or 20 µM PGA2 led to decreases in cell numbers, coupled with increased numbers of apoptotic and dead cells. Similar exposures to 10 µM PGA2 (24 h) led to substantial increases in apoptotic cells, confirmed by a terminal deoxynucleotidyl transferase dUTP nick end labeling assay on a flow cytometer. The influence of PGA2 treatments increased with dosage, as we recorded about 20% apoptosis at 24 h post-PGA2 treatments (10 µM) and about 34% apoptosis at 24 h post-30 µM treatments. PGA2 treatments led to 10- to 30-fold increases in messenger RNAs (mRNAs) encoding apoptosis-specific caspases-1, -2, -3, and -5 at 12 h and 40- to 60-fold increases in mRNAs encoding caspases-1 and -2, 10-fold increases for caspases-3 and -5 at 24 h. These findings strongly support our hypothesis that PGs induce apoptosis in an insect cell line and confirm an additional PG action in insect biology.

Temperature-dependent variations in toxicity of diamide insecticides against three lepidopteran insects.

The effect of temperature on the toxicities of four diamide insecticides (chlorantraniliprole, cyantraniliprole, flubendiamide, tetraniliprole) against three lepidopteran insects (Helicoverpa armigera, Plutella xylostella, Athetis lepigone) were determined from 15 to 35 °C by exposing third-instar larvae to dip-treated cabbage leaf. The results indicated that increase in temperature led to an increase significantly and regularly in the toxicities of the four diamide insecticides against P. xylostella and H. armigera, but not for A. lepigone. The temperature coefficients (TCs) of the four diamide insecticides increased from 15 to 35 °C. Tetraniliprole for H. armigera (+825.83), chlorantraniliprole for P. xylostella (+315.65) and cyantraniliprole for H. armigera (+225.77) exhibited high positive TCs. For A. lepigone, temperature had a positively weak or no effect on the toxicities of most of the diamide insecticides from 20 to 30 °C, but a higher effect from 30 to 35 °C. In addition, the toxicities of chlorantraniliprole, cyantraniliprole and tetraniliprole all decreased from 15 to 20 °C. This study can guide pest managers in choosing suitable ambient field temperature when spraying diamide insecticides against lepidopteran insects.

Analysis of Differentially Expressed Transcripts in Apolygus lucorum (Meyer-Dür) Exposed to Different Temperature Coefficient Insecticides.

The existence of a temperature effect of insecticides frustrated the control of the green plant bug Apolygus lucorum (Meyer-Dür). Previous studies mostly focused on the application of insecticides, but the underlying mechanism remains incompletely understood. Here, we report a transcriptome profiling of A. lucorum treated by three kinds of temperature coefficient insecticides (TCIs) (positive TCI: imidacloprid, negative TCI: b-cypermethrin and non-effect TCI: phoxim) at 15 °C, 25 °C and 35 °C by using next- and third-generation RNA-Seq methods. A total of 34,739 transcripts were annotated from 277.74 Gb of clean data. There were more up-regulated transcripts than down-regulated transcripts in all three kinds of TCI treatments. Further Venn diagrams indicate the regulatory transcripts and regulatory modes were different at the three temperatures. The responses to imidacloprid involved more detox and stress response transcripts such as cytochrome P450 (CYP450), carboxylesterase (CarE) and catalase (CAT) at 35 °C, which was the case for beta-cypermethrin at 15 °C. UDP-glucuronyltransferase (UGT) and heat shock protein (HSP) transcripts were heavily involved, and thus deserve particular note in the temperature effect of insecticides. This high-confidence transcriptome atlas provides improved gene information for further study on the insecticide temperature effect related physiological and biochemical processes of A. lucorum.

Treating wheat seeds with neonicotinoid insecticides does not harm the rhizosphere microbial community.

Wheat aphids damage wheat plants directly by feeding on them and indirectly by transmitting plant pathogenic viruses, both of which result in low yield and plant death. Due to their high root absorption and systemic characteristics, neonicotinoid insecticidal seed treatments are increasingly applied to control wheat aphids throughout the growing season in China. Ecological concerns are raised in some research, because neonicotinoids can persist and accumulate in soils. They are prone to leach into waterways, and are found in crop nectars and pollens, where they may be harmful to pollinators. Less information is available about the effect of neonicotinoid seed treatments on soil microorganisms. Here, we posed the hypothesis that neonicotinoids are not harmful to soil microbial communities. We tested our hypothesis by evaluating the effects of two neonicotinoids, imidacloprid and clothianidin, on soil microbiomes using high-throughput sequencing during three points in the wheat growth season. Except for the imidacloprid-treated soil in the seedling stage, the community richness and diversity were not affected according to Chao1, ACE and the Shannon indices, and species distribution histogram at the phylum level. However, Beta diversity indices showed that the species richness of the bacterial and fungal community was suppressed by neonicotinoids in seedling stage (high neonicotinoids concentrations), whereas by the reviving period, the changes reverted into stimulation of the soil microorganisms (low neonicotinoids concentrations). Overall, the general microbiome recovered at the end of the wheat planting season. Generally, wheat seed dressing with neonicotinoid insecticides control aphids during the entire growth period, and have no lasting adverse effects on the soil microbiome. This study provides an understanding of the influence of neonicotinoids on crop land ecology at the level of soil microbe communities.

Characterization of cell lines derived from the southern armyworm, Spodoptera eridania.

Spodoptera eridania (southern armyworm) is a polyphagous pest of many plants, including field crops, vegetables, fruits, and ornamentals. Larvae are leaf feeders, defoliating many crops in the tropics and subtropics of the western hemisphere. In this study, cell lines from S. eridania were established to support research focused on the development of advanced pest management technologies. We generated seven cell lines from larval tissues: three from nervous tissues, two from testes, and two from fat bodies. These cell lines have been passaged 18-57 times, indicating they are established lines. They are maintained in EX-CELL 420 or a combination of L15 + EX-CELL 420 media. The identities of the cell lines were confirmed by DAF-PCR and their doubling times ranged from 42 to 110 h. Microscopy indicated the presence of one or more morphologically distinct cell types in each cell line. We identified a catalase gene in all seven cell lines. H2O2 treatment suppressed the expression of catalase and led to a reduction in catalase activity. This is the first report of cell lines established from S. eridania, and these cell lines are now available to researchers worldwide on request.

Lattice Boltzmann simulations of liquid CO2 displacing water in a 2D heterogeneous micromodel at reservoir pressure conditions.

We employed the color-fluid lattice Boltzmann multiphase model to simulate liquid CO2 displacing water documented in experiments in a 2D heterogeneous micromodel at reservoir pressure conditions. The main purpose is to investigate whether lattice Boltzmann simulation can reproduce the CO2 invasion patterns observed in these experiments for a range of capillary numbers. Although the viscosity ratio used in the simulation matches the experimental conditions, the viscosity of the fluids in the simulation is higher than that of the actual fluids used in the experiments. Doing so is required to enhance numerical stability, and is a common strategy employed in the literature when using the lattice Boltzmann method to simulate CO2 displacing water. The simulations reproduce qualitatively similar trends of changes in invasion patterns as the capillary number is increased. However, the development of secondary CO2 pathways, a key feature of the invasion patterns in the simulations and experiments, is found to occur at a much higher capillary number in the simulations compared with the experiments. Additional numerical simulations were conducted to investigate the effect of the absolute value of viscosity on the invasion patterns while maintaining the viscosity ratio and capillary number fixed. These results indicate that the use of a high viscosity (which significantly reduces the inertial effect in the simulations) suppresses the development of secondary CO2 pathways, leading to a different fluid distribution compared with corresponding experiments at the same capillary number. Therefore, inertial effects are not negligible in drainage process with liquid CO2 and water despite the low Reynolds number based on the average velocity, as the local velocity can be much higher due to Haines jump events. These higher velocities, coupled with the low viscosity of CO2, further amplifies the inertial effect. Therefore, we conclude that caution should be taken when using proxy fluids that only rely on the capillary number and viscosity ratio in both experiment and simulation.

Prostaglandin actions in established insect cell lines.

Prostaglandins (PGs) are oxygenated metabolites of arachidonic acid (AA) and two other C20 polyunsaturated fatty acids that serve as biochemical signals mediating physiological functions. We reported that PGs influence protein expression in insect cell lines, which prompted the question: do PGs influence cell proliferation or viability in insect cell lines? Here, we report on the outcomes of experiments designed to address the question in cell lines from three insect orders: Hemiptera (squash bug, Anasa tristis, BCIRL-AtE-CLG15A), Coleoptera (red flour beetle, Tribolium castaneum, BCIRL-TcA-CLG1), and Lepidoptera (tobacco budworm, Heliothis virescens, BCIRL-HvAM1). Treating the insect cell lines with PGA1, PGA2, or PGD2 led to dose-dependent reductions in cell numbers. All three cell lines were sensitive to PGA1 and PGA2 (IC50s = 9.9 to 26.9 µM) and were less sensitive to PGD2 (IC50s = 31.6 to 104.7 µM). PG treatments also led to cell death at higher concentrations, as seen in mammalian cell lines. PGE1, PGE2, and PGF2α treatments did not influence AtE-CLG15A or HvAM1 cell numbers at lower concentrations, but led to dose-related reductions in TcA-CLG1 cells at higher concentrations. Similar treatments with pharmaceutical inhibitors of PG biosynthesis also led to reduced cell numbers: MAFP (inhibits phospholipase A2), indomethacin (inhibits PG biosynthesis), and esculetin (inhibits lipoxygenase). Because these pharmaceuticals are used to relieve inflammation and other medical issues in human medicine, they are not toxic to animal cells. We infer PGs are necessary in optimal quantities for ongoing homeostatic functions in established cell lines; in quantities outside the optimal concentrations, PGs are deleterious.

Cell lines derived from the squash bug, Anasa tristis (Coreidae: Hemiptera).

The squash bug, Anasa tristis, is a pest of cucurbits that exerts direct damage on crops and is a vector of plant pathogens. We established cell lines from this insect to serve as tools for basic biology, including virology and immunology, as well as applied studies, such as insecticide development programs. We initiated 15 cell cultures, using nine media or combinations of media. The media yielding the best results were a modification of Kimura's medium and a combination of two commercially available cell culture media (EX-CELL 420 and L15). We designated the two cell lines as BCIRL-AtE-CLG11 and BCIRL-AtE-CLG15. From the AtE-CLG15 line, we isolated two sub-lines, A and B. Of these, the most consistently replicating line was AtE-CLG15A. We determined the doubling time of this line (190 h) and its mean cell diameter (14.5 ± 0.7 µm). We characterized the AtE-CLG15A line using DAF-PCR. The BCIRL-AtE-CLG15A cell line is now available for researchers world-wide.

Attraction of Coffee Bean Weevil, Araecerus fasciculatus, to Volatiles from the Industrial Yeast Kluyveromyces lactis.

The coffee bean weevil (CBW), Araecerus fasciculatus (De Geer, 1775) (Coleoptera: Anthribidae) is an important pest of stored products such as grains, coffee beans, cassava, and traditional Chinese medicine materials. In China, CBW causes large losses of Daqu, a traditional Chinese liquor fermentation starter, and, unfortunately, the use of conventional insecticides against CBW is not suitable in Daqu storage. We found CBW to be highly attracted to fermenting yeast cultures, such as Kluyveromyces lactis. Eight volatile compounds, produced by fermenting cultures and not by sterile samples, were identified by gas chromatography coupled with mass spectrometry. Five of these substances elicited significant responses in Y-tube behavioral bioassays. Field trapping experiments revealed 2-phenylethanol and 2-phenylethyl acetate to be crucial for attraction of CBW. Results show that yeast volatiles play an important role in host location, and that 2-phenylethanol and 2-phenylethyl acetate could be utilized as potential attractants in monitoring and control systems against this important pest.

The Joint Toxicity of Different Temperature Coefficient Insecticides on Apolygus lucorum (Hemiptera: Miridae).

The effect of temperature on the cotoxicity coefficient (CTC) value was used to evaluate mixture efficacy of different temperature coefficient chemicals from 15 to 35°C by exposing third-instar Apolygus lucorum (Meyer-Dür) to dip-treated asparagus bean pods. The results indicated the joint toxicity of same temperature coefficient insecticide (TCI) types were unaffected by temperature. This means that even when temperatures change, the mixture ratios of the highest CTC values remained the same, and the effect of temperature on the joint toxicity of same TCI types was only on the CTC values. However, the effect of temperature was variable when considering the joint toxicity of different TCI types. The effect of temperature on the joint toxicity of both strong positive and strong negative TCI types was clear, and the highest CTC values of mixture ratios changed with temperature regularly. When comparing the influence of temperature between strong/slight positive/negative insecticides, the results indicated a greater influence of the strong TCI. Paradoxically, the highest CTC value of the imidacloprid and methomyl mixture did not change with temperature changes consistently, even with the variance of imidacloprid ratios, a strong TCI. These results will guide pest managers in choosing the most effective insecticide mixtures for A. lucorum control under given environmental conditions.

Synthesis and biological activity of novel benzimidazole derivatives as potential antifungal agents.

In the present study, a series of novel benzimidazole derivatives containing chrysanthemum acid moieties was designed and synthesized. Preliminary investigation of biological activity indicated that all of the compounds exhibited lower activity than that of beta-cypermethrin against Plutella xylostella and Lipaphis erysimi; meanwhile, they showed good inhibitory activity against Botrytis cinerea and Sclerotinia sclerotiorum in vitro. The fungicidal activity of compound 8a against B. cinerea was approximately equal to that of thiabendazole and was twice as active against S. sclerotiorum as was thiabendazole. In addition, compound 9e displayed the most potent inhibitory activity against both fungi and was almost twice as potent as thiabendazole.