Behavioural Bioassays and Identification of Cashew Leaf and Stem Volatiles Mediating Attraction to the Stem Girdler, Analeptes trifasciata (Coleoptera: Cerambycidae)

The cashew stem girdler, Analeptes trifasciata Fabricius (Coleoptera: Cerambycidae), damages cashew by its girdling activities in the stem thereby causing huge economic losses. The stem girdler is managed through cultural practice of burning girdled stems and beetles, though this has drawbacks. The objective of this study was to explore the cues mediating attraction to the cashew host plant;hence the role of olfaction in host plant location by A. trifasciata underlying the semio-chemical option for controlling this insect pest. A diffusional Y-tube olfactometer was used to study the behavioural response of A. trifasciata, to freshly cut cashew stem and leaves odour sources. Methanol-extract of these plant tissues was subjected to the coupled gas chromatography-mass spectrometry (GC-MS) analysis. Y-tube olfactometric assays demonstrated that both sexes oriented towards and spent significantly more time in stem odour arm compared to the leaf odour arm in both male (male: t = 2.228, d.f = 11, P = 0.040) and female (t = 2.341, d.f = 11, P = 0.040). A combination of fatty acids, amino acids and carbohydrates were detected in cashew stems. Some of these fatty acids are attractants to other insect pests. It is suspected that these fatty acid blends may possibly be responsible for facilitating host plant location by both sexes. In conclusion, both sexes were independently and strongly attracted to the stem volatiles;this study opens the possibility of utilizing cashew stem volatiles as surveillance and control tools.

Behavioral responses of potato tuber moth (Phthorimaea operculella) to tobacco plant volatiles

Potato tuber moth(PTM)Phthorimaea operculella,also known as tobacco splitworm,is an important pest of tobacco plants.The knowledge on the interaction of tobacco plant volatiles and PTM behavior is limited.To clarify the effect of tobacco plant volatiles on the orientation and oviposition behaviors of PTM and to identify potential compounds for PTM control,tobacco plant volatiles were collected by headspace collection method,and volatile compounds were identified by gas chromatography-mass spectrometry.Thirteen electrophysiological active compounds were screened by employing coupled gas chromatography-electroantennogram detection and from which nine available compounds were further verified by electroantennogram recording.cis-3-Hexen-1-ol showed significant attractant effect on the orientation behaviors of both male and female moths.Nonanal and decanal could only attract females,while octanal exhibited repellent effect on males.Oviposition selection experiment indicated that nonanal,decanal,decane and methyl hexadecanoate could stimulate the gravid females to lay more eggs,while octanal and 2,6-bis(1,1-dimethylenthyl)-4-methyl phenol inhibited their oviposition.Our study added more compounds to the list that could serve as potential PTM deterrents or attractants.

Antagonistic Activities of Volatiles from Four Strains of Bacillus spp. and Paenibacillus spp. Against Soil-Borne Plant Pathogens

The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants, induced the mycelial morphological abnormalities, and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates. Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension. An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi, including Ascochyta citrullina, Alternaria solani, Alternaria brassicae, and so on. Interactions mediated by microbial volatiles could be widespread in soils, and volatiles may play an important role in reducing disease levels. A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa （BMP-11）, Bacillus subtilis （BL02）, and Bacillus pumilus （BSH-4 and ZB 13）. Through headspace sampling and GC-MS analysis, a rich profile was found from B. subtilis and overlapping volatile patterns could be found among the different species. Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.

Electrophysiological responses of the rice striped stem borer Chilo suppressalis to volatiles of the trap plant vetiver grass (Vetiveria zizanioides L.)

Vetiver grass （Vetiveria zizanioides L.） was previously found to effectively attract female adults of Chilo suppressalis （Walker）, an important pest of rice. To determine the volatile compounds involved in this attraction, electroantennography （EAG） responses to seven synthetic volatiles released from vetiver plants were examined. Our results indicated that the responses of C. suppressalis adult antennae to the different compounds varied widely. The compounds elicited strong EAG responses in female antennae were subsequently selected for further EAG response tests, namely, caryophyllene, β-ocimene, linalool and a-pinene. EAG responses to a combination of these four compounds did not differ significantly from the individual compounds. However, pair combination tests indicated that 0.01μg μL-1linalool and 50 μg μL-1 α-pinene, 50 μgμL-1 caryophyllene and 0.01μg μL-1 linalool, 0.01 μg μL-1 13-ocimene and 0.01 μg μL-1 linalool, and 0.01μg μL-1 β-ocimene and 50 μg μL-1 caryophyllene elicited significantly greater EAG responses in 3-day female moths compared to the 1-day female. These compound combinations and the corresponding ratios are probably playing an important role in attracting female adults of C. suppressalis to the vetiver grass.

Development of volatiles and odor-active compounds in Chinese dry sausage at different stages of process and storage

The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidation(11.30%–34.92%)played a key role in flavor profile during process and storage.A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices,while a gradual decrease of each volatile was detected during storage except signifi cant increase of volatiles from lipid oxidation and esterifi cation.15 and 6 odor-active compounds were respectively correlated(P<0.05)with the process and storage time.Level of heptanal,1-octen-3-ol,the ethyl of 2-methylbutanoic,3-methylbutanoic,butanoic,benzoic,hexanoic,heptanoic,octanoic and decanoic acid were best discriminators of process stage,while(E)-2-nonenal,ethyl hexanoate,ethyl heptanoate,and methyl decanoate,were marker compounds of storage time.An objective method was established to evaluate the stages of process and storage for samples.

Electrophysiological responses of Plutella xylostella to 9 different plant volatiles

Plutella xylostella is the main pest of cruciferae plants in the worldwide fields.The volatiles released from host plants serve vital roles in host-finding and oviposition behavior.Electroantennograms were recorded from male and female Plutella xylostella to 9 different plant volatiles(cabbage Brassica oleracea L.var.capitata,baby bokchoi Brassica chinensis L.,broccoli Brassica oleracea L.var.botrytis L.,Chinese cabbage Brassica pekinensis Rupr.,Radish Raphanus sativus L.,towel gourd Luffa Cylindrica Roem.,eggplant Solanum melongena L.,tomato Solanum lycopersicum,pepper Capsicum annuum L.) in healthy/injured status.The statistic analysis show there is a significant difference of EAG relative values between cruciferae and non-cruciferae volatiles.The EAG relative values of injured plant volatiles to both male and female changed a lot during the tests.Multiple-ANOVA analysis represents cross factors(sex,host-plant,plant status) showed a great interactive impacts to the EAG-RV.

Attraction of bruchid beetles Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) to host plant volatiles

Host-plant volatiles play an important role as cues for herbivores in search of resources, mates and oviposition sites in complex environments. Plant volatile-based attractants can be developed for pest monitoring and control. Previously, we indicated that mated female adults of Callosobruchus chinensis showed choice preference behavior toward 2-hexenal and benzaldehyde. Our objective here was to investigate the synergistic effect of host-derived attractive volatiles in attracting C. chinensis under laboratory and field conditions in Shanxi Province, China. We hypothesized that the ratio and concentration of volatiles derived from Vigna radiata play critical roles for C. chinensis in locating this host. Therefore, we collected and identified the volatiles of mungbean by using headspace collection and GC-MS. The effectiveness of different ratios and concentrations of two compounds (2-hexenal and benzaldehyde) that elicit C. chinensis searching behavior were examined in Y-tube olfactometer assays. The combination of 300 μg μL^–1 2-hexenal and 180 μg μL^–1 benzaldehyde loadings exhibited a synergistic effect on attracting C. chinensis (82.35%). Compared to control traps, the adults were significantly attracted to traps baited with blends, and more attraction to females than males was found for blend traps in the field experiments. Our results suggest that blends of this specific concentration and ratio of benzaldehyde and 2-hexenal can be used in traps as attractants for C. chinensis monitoring and control in the field.

Allelopathy of Gaseous Volatiles of Eupatorium adenophorum on Seed Germination and Seedling Growth of Pinus yunanensis

[ Objective] The paper was to understand allelopathy of gaseous volatiles of Eupatorium adenophorum stems and leaves on seed germination and seedling growth of P/nus yunnanens/s. [ Method] P. yunnanens/s seeds were treated by fresh stems and leaves of E. adenophorum in translucent airtight container under high concentration （0.069 4 g/cm3 ）, middle concentration （0.023 1 g/cm3 ） and lower concentration （0. 007 7 g/cm3 ）, respectively. [ Result] Gaseous volatiles affected seed germination process; with the increasing processing concentration, the day on which seeds began to germinate and the day reaching germination peak were delayed, and the germination quantity on the day reaching germination peak was decreased ; the day on which the germination quantity began to significantly re- duce was delayed ; the process curve was developed from sudden increase and sudden decrease to gentle change, and nearly became a beeline at high concentration. The effects of gaseous volatiles on seed germination （ seed germination rate, germination potential, germination index） and seedling growth （fresh weight, dry weight, radicle length, hypceotyl length） of P. yunnanens/s were basically consistent, showing a regularity that high concentration had stronger inhibition effect and the inhibition effect became weaker with the decreasing concentration of E. adenophorum. E. adenophorum was widely distributed under P. yunnanens/s forests, and might affect natural regeneration and growth of P. yunnanens/s via allelopathy. [ Conclusion ] The paper provides reference for scientific management of P. yunnanens/s forests.

Analysis of Leaf Volatiles of Crabapple (<i>Malus</i>sp.) Individuals in Different Aphids’ Resistance

The aim of this experiment was to analyze the leaf volatiles of crabapple (Malus sp.) individuals at different aphid’s resistance, to ascertain the particular ingredients which has lure or aversion effects on aphid, and to provide reference for finding out a simple method to control effectively aphids. Volatiles of leaves from twenty-one different crabapple individuals were evaluated with the method of head space-solid phase micro-extraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS). Volatiles profiles of them were then compared. There are one hundred eighty-six kinds of volatiles were detected with varied contents found in different individuals. And all plants contain eight kinds of common components: 3-Hexen-1-ol, acetate, (Z)-, 4-Hexen-1-ol, (Z)-, n-Decanal, n-Tetradecane, .alpha.-Farnesene, Diethyl Phthalate, Oxime-, methoxy-phenyl- and Dibenzofuran-, wherein the relative content of higher have 3-Hexen-1-ol, acetate, (Z)- and 4-Hexen-1-ol, (Z)-. Specific volatile substances in high resistance plants contain 3-Hexenal, (Z)- and 2-Hexenal, (E)-. Leaf volatiles differ in twenty-one crabapple individuals. High resistance plants specific volatile substances contains 3-Hexenal, (Z)-, 2-Hexenal, (E)- and other small molecular volatile substances, and no-resistance plants all have .beta.-Farnesene.

Deep Volatiles as the Key for Energy and Environments of the Four-Dimensional Earth System

Carbon, hydrogen, oxygen, nitrogen, sulfur, and their compounds are volatile components that dominate the thin and fragile atmosphere, hydrosphere, and biosphere on Earth’s habitable surface. However, the vast majority of these volatiles are hidden in the deep interior, where the high pressure–temperature conditions drastically and categorically alter the physics and chemistry of the volatiles. Like the bloodstream of an organism, the circulations and interactions of volatiles in the deep Earth modulate climate, resources, energy, natural hazards, and other factors that define the Earth as a unique living and changing planet.

Nanorocks, volatiles and plate tectonics

The global geological volatile cycle(H,C,N)plays an important role in the long term self-regulation of the Earth system.However,the complex interaction between its deep,solid Earth components(i.e.crust and mantle),Earth’s fluid envelopes(i.e.atmosphere and hydrosphere)and plate tectonic processes is a subject of ongoing debate.In this study we want to draw attention to how the presence of primary melt(MI)and fluid(FI)inclusions in high-grade metamorphic minerals could help constrain the crustal component of the volatile cycle.To that end,we review the distribution of MI and FI throughout Earth’s history,from ca.3.0 Ga ago up to the present day.We argue that the lower crust might constitute an important,longterm,volatile storage unit,capable to influence the composition of the surface envelopes through the mean of weathering,crustal thickening,partial melting and crustal assimilation during volcanic activity.Combined with thermodynamic modelling,our compilation indicates that periods of well-established plate tectonic regimes at<0.85 Ga and 1.7-2.1 Ga,might be more prone to the reworking of supracrustal lithologies and the storage of volatiles in the lower crust.Such hypothesis has implication beyond the scope of metamorphic petrology as it potentially links geodynamic mechanisms to habitable surface conditions.MI and FI in metamorphic crustal rocks then represent an invaluable archive to assess and quantify the co-joint evolution of plate tectonics and Earth’s external processes.

Volatiles from <i>Acer truncatum</i>Flowers

Plant volatile organic compounds (Biogenic Volatile Organic compounds, referred BVOCs) have a significant impact on the atmospheric environment, air quality and human health. This experiment takes Acer truncatum flowers as the research object, uses solid-phase micro-extraction combine GC-MS (SPME-GC-MS) to detect the main component of volatiles released by the flowers from 10 individual trees of Acer truncatum (Acer truncatum Bunge). The results showed that 37 kinds of volatiles were detected and they are belonged to four types organic compouds, such as terpenoids, alcohols, ketones, esters. According to the analysis of the main components of Acer truncatum flower volatiles includes Fluorene, 4,8 -Dimethyl-1,3 (E), 7-Nonene, (cis, trans)-2,6-Dimethyl-2,4,6-triene-Partenkirchen, Myrcene, Basil hexene, 3-Carene, (E)-Basil, Camphene, Caryophyllene, Linalool, α-Terpinolene, O-cymene, 3-Vinyl-1,2-dimethyl-1, Eucalyptus alcohols and Alcohol vinegar-12. However, there were no significant differences between individual trees in terms of obscure material O-cymene, Eucalyptus alcohols, Alcohol vinegar-12, as well as the significant differences in terms of remaining volatiles.

Screening of Slow Release Solvents for Plant Volatiles

[Objective] The paper was to study the slow release effects of eight common kinds of slow release solvents on n-hexane, and to provide a reference for the construction of slow release system of attractants or repellents synthesized by plant volatiles. [Method] The effect of slow release solvents on volatile quantity and release rate of n-hexane was compared by weight loss method. [Result] Under indoor natural conditions [(22±2) ℃,RH 50%±10%], the slow release effect of lubricating oil on n-hexane was the best, followed by liquid paraffin. The best ratio of slow release solvent(lubricating oil and liquid paraffin) and n-hexane was 5∶1 and the best mixing time was 3 h, which improved the slow release effects of n-hexane by6.3 and 4.7 times, and prolonged the half-life of n-hexane by 1.3 and 1.0 times, respectively. Slow release solvents mainly affected the post-half-life period of n-hexane, and the release rates of n-hexane mixed with lubricating oil and liquid paraffin were decreased by 10.4 and 7.7 times, respec-tively. During the half-life period, the release rates of n-hexane were decreased by 1.3 and 1.0 times, respectively. [Conclusion] Two kinds of slow release solvents with good slow release effect on volatile n-hexane are screened out, and the proportion and mixing time of slow release solvent and volatile are determined, which will provide technical support for the construction of plant volatile slow release system.

Volatiles from <i>Prunus persica</i>Flowers and Their Correlation with Flower-Visiting Insect Community in Wanbailin Ecological Garden, China

Object: To investigate the VOCs from living Prunus persica flowers of different branches and their correlation with floral insects. Special, dominant and 20 VOCs were analysed from living Prunus persica flowers captured by closely and circularly headspace way in adsorbent tubes and ATD-GC/MS on 29 April in Wanbailin Ecological Garden, China. VOCs from high altitude tree are more than low altitude in sunny site, and floral volatile constituents from upslope branches are less than downslope of the same tree on high altitude. Special floral VOCs were alpha-dimethyl-benzenemethanol, isopropyl palmitate, ethylbenzene, p-xylene, acetophenone, 3-ethyl-2-methyl-Heptane on sunny slope, and propylene glycol, decanal, hexadecane on shady slope. Dominant VOCs founded during 8 temporal quanta were toluene, hexane, 2-ethyl-1-hexanol, dodecane, pentadecane. Floral VOCs’ number from sunny slope was significantly negative correlated with flower-visiting insect community richness, abundance, diversity on sunny or shady slope, which from shady slope was significantly positive correlated with flower-visiting insect community parameters on both slopes tried dividing insects visiting floral branches from Prunus persica in sunny site with n/2 + 1 or n/2 - 1, and shady site with n/2 before sampled volatiles day. On sampled volatiles day, 2-ethyl-1-hexanol from sunny slope was significantly positive correlated with flower-visiting insect community parameters on shady slope (P Prunus persica on sunny slope, and even floral branches kept on shady slope.

Volatiles (S-CO₂-H₂O-Cl-F) Behavior during the AD 1944 Eruption

The AD 1944 is the last vulcanian-effusive eruption of Vesuvius volcano. I have reviewed most of the major and volatile elements in order to better understand the eruptive dynamic of this hazardous volcano. These volcanic products were basically formed by at least two main petrogenetic mechanisms: 1) mixing, 2) crystal fractionation. Crystal fractionation plays a major role in the evolution of the volcanic products of the AD 1944 eruption. According to the major elements data, several fractionation lines can be employed. Volatile data are analyzed in sequence. Indeed, the volatile data allow an insight into the exsolution and degassing processes occur during the growth and eruption of the AD 1944 eruption. Some inferences are also made on the exsolution and degassing depth. The volatile data illustrate a sequential order of exsolution for the AD 1944 eruption: Cl-H2O-CO2-S and finally as volatile phase degassed fluorine. The eruption has not interacted with external water. An early exsolution of Cl in Cl-rich magmas is also confirmed by experimental and geological studies (3 - 4 Kbars) coinciding with the deep magma reservoir.

Design and Availability Research of a Flammable and Explosive Volatiles Monitoring and Early Warning System (FEVMEW) for the Bus Crowded Places

In order to reduce the arson or accidental fire losses, we developed a gas sensitive detector used for the rapid detection and early warning of flammables in crowded places such as buses. A MEMS (Micro-Electro-Mechanical System) based thin film semiconductor was fabricated as the gas sensor. To obtain the target gas selective response, the surface of the sensitive film was modified with highly active metal catalytic nano-particles. Thus the anti-interference ability was improved and the false alarm rate was effectively reduced. Furthermore, the modular embedded system for information acquisition and transmission was developed. Supported by the Airflow Precision control system (APs), the rapid warning of volatile gas of flammable substances was realized. Experiments showed that RAs has satisfied selectivity to volatiles of usual flammable liquid, such as the output voltage reaches 3 V (0 - 3.3 V). With simulation about the actual installation state in bus, MWs sounds an alarm at 2 minutes after splashing 50 mL 92# petrol to the floor. For the last two years, FEVMEW has been integrated into more than 4000 buses in Hefei. This design has been proved feasible according to the actual operation.

Comparison of host volatiles under different physiological states and electroantennogram responses of Semanotus bifasciatus (Motschulsky) to these volatiles

Based on an analytical TCT-GC/MS method, volatile compounds of branches of Platycladus orientalis under three physiological states （healthy, weak and baited trees） were analyzed. The results showed that α-pinene, β-phellandrene, 3-careen, limonene and thujopsene were released under all three physiological states. There were other kinds of volatiles released from branches of weak P. orientalis trees, such as camphene, γ-terpinene, （＋）-4-carene and cedrene, but these four volatiles compounds were not released from the branches of healthy P. orientalis. Volatile components from the physically damaged branches of P. orientalis had changed. β-terpinene, mycrene, isocaryophillene and caryophyllene were identified in both healthy and weak branches of P. orientalis. Only cedrene was identified in the baited wood. Electroantennogram （EAG） tests were conducted with nine volatile compounds from the branches of P. orientalis. Antennnae of male and female Semanotus bifasciatus （Motschulsky） were highly sensitive to these nine volatile compounds. Cedrene elicited the strongest response, whereas β-terpinene the lowest. Males and females showed no signifi-cant difference in their EAG responses to the nine volatile compounds.

Volatiles from Sophora japonica flowers attract Harmonia axyridis adults(Coleoptera: Coccinellidae)

The multicolored Asian lady beetle, Harmonia axyridis(Coleoptera: Coccinellidae), is a common generalist predator in China and is occasionally found gathering on the Chinese pagoda tree, Sophora japonica, in summer. In a field investigation, we found that H. axyridis adults preferred S. japonica during its flowering period even though their optimal prey(aphid) is absent at this time. In addition, male and female adults were attracted to S. japonica flowers to a similar extent in a Y-tube olfactometer assay. Using coupled gas chromatography-electroantennogram detection(GC-EAD), we identified a flower odor component(nonanal) that elicited a significant electrophysiological response in H. axyridis. Electroantennogram(EAG) dose-dependent responses revealed that the amplitude of the adult beetle's EAG response increased with increasing concentration of nonanal, peaking at 10 mg mL^(–1). In Y-tube olfactometer behavioral tests, H. axyridis adults preferred a 10 mg mL^(–1) nonanal source over a 100 mg mL^(–1) diluent. Under field conditions, the adults were significantly attracted to both concentrations(10 and 100 mg mL^(–1)), and high concentrations generally had greater attraction. All these results suggest that nonanal, a volatile compound of S. japonica flowers, greatly attracts H. axyridis adults. This study provides a basis for the development of synthetic attractants of H. axyridis, with the potential to promote biocontrol services of this generalist predator in the native area(e.g., China) and to suppress its population by mass trapping in its invasive areas.

Characterization of flavor fingerprinting of red sufu during fermentation and the comparison of volatiles of typical products

Traditional Chinese red sufu is a popular condiment,and typical flavor is an important indicator of sensory qualities in commercial products.In this study,the volatile aroma analysis of Wangzhihe red sufu(WRS)from different fermentation stages and four typical red sufu products from different locations was carried out by gas chromatography-mass spectrometry(GC–MS),gas chromatography-mass spectrometry/olfactory(GC–MS/O),electronic nose(E-nose)and sensory evaluation.Results showed that 106 volatile compounds were identified in Wangzhihe red sufu during fermentation process,in which phenolics and alcohols were dominant at molded and salted phetze stages,while esters and alcohols became predominate at post-fermentation stage.The volatile aroma substances varied at each fermentation stage.Furthermore,86 volatiles,including 16 aroma-active compounds,were detected in four typical red sufu products.The multivariate analysis results showed the difference in samples from different fermentation stages and typical red sufu products according to GC–MS and E-nose analysis.Combined with flavor omics,discriminant model was established for effective discrimination of samples from different fermentation stages and locations,as well as references to sufu maturity extent.The study presented a new strategy for quality evaluation of red sufu,which could be the supplement to quality evaluation standards.

Olfactory Response of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) to Volatiles Emitted by Mungbean Plants

Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée）, a crucial insect pest of maize in China, by Trichogramma ostriniae Pang Chen. This study investigated the behavioural responses of T. ostriniae to plant volatiles emitted from whole plants, leaves, and flowers of prostrate and erect varieties of mungbean in a 4-armed olfactometer. Female parasitiods were significantly attracted to the odours from some varieties of prostrate mungbean when the visit duration and the number of visits were considered, but were not attracted to the odours from any erect varieties. The attractive odours were shown to emanate from the leaves, rather than from the flowers of prostrate mungbean plants. These results have implications for the augmentation of Trichogramma parasitoids in bio-control of O. furnacalis and other crop pests.