(1<Emphasis Type="Italic">S</Emphasis>,3<Emphasis Type="Italic">R</Emphasis>)-<Emphasis Type="Italic">cis</Emphasis>-Chrysanthemyl Tiglate: Sex Pheromone of the Striped Mealybug, <Emphasis Type="Italic">Ferrisia virgata</Emphasis>

Derivatives of 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic acid (chrysanthemic acid) are classic natural pyrethroids discovered in pyrethrum plants and show insecticidal activity. Chrysanthemic acid, with two asymmetric carbons, has four possible stereoisomers, and most natural pyrethroids have the (1R,3R)-trans configuration. Interestingly, chrysanthemic acid–related structures are also found in insect sex pheromones; carboxylic esters of (1R,3R)-trans-(2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl)methanol (chrysanthemyl alcohol) have been reported from two mealybug species. In the present study, another ester of chrysanthemyl alcohol was discovered from the striped mealybug, Ferrisia virgata (Cockerell), as its pheromone. By means of gas chromatography–mass spectrometry, nuclear magnetic resonance spectrometry, and high-performance liquid chromatography analyses using a chiral stationary phase column and authentic standards, the pheromone was identified as (1S,3R)-(?)-cis-chrysanthemyl tiglate. The (1S,3R)-enantiomer strongly attracted adult males in a greenhouse trapping bioassay, whereas the other enantiomers showed only weak activity. The cis configuration of the chrysanthemic acid–related structure appears to be relatively scarce in nature, and this is the first example reported from arthropods.     

<Emphasis Type="Italic">Sphagnum</Emphasis> Species Modulate their Phenolic Profiles and Mycorrhizal Colonization of Surrounding <Emphasis Type="Italic">Andromeda polifolia</Emphasis> along Peatland Microhabitats

Sphagnum mosses mediate long-term carbon accumulation in peatlands. Given their functional role as keystone species, it is important to consider their responses to ecological gradients and environmental changes through the production of phenolics. We compared the extent to which Sphagnum phenolic production was dependent on species, microhabitats and season, and how surrounding dwarf shrubs responded to Sphagnum phenolics. We evaluated the phenolic profiles of aqueous extracts of Sphagnum fallax and Sphagnum magellanicum over a 6-month period in two microhabitats (wet lawns versus dry hummocks) in a French peatland. Phenolic profiles of water-soluble extracts were measured by UHPLC-QTOF-MS. Andromeda polifolia mycorrhizal colonization was quantified by assessing the intensity of global root cortex colonization. Phenolic profiles of both Sphagnum mosses were species-, season- and microhabitat- dependant. Sphagnum-derived acids were the phenolics mostly recovered; relative quantities were 2.5-fold higher in S. fallax than in S. magellanicum. Microtopography and vascular plant cover strongly influenced phenolic profiles, especially for minor metabolites present in low abundance. Higher mycorrhizal colonization of A. polifolia was found in lawns as compared to hummocks. Mycorrhizal abundance, in contrast to environmental parameters, was correlated with production of minor phenolics in S. fallax. Our results highlight the close interaction between mycorrhizae such as those colonizing A. polifolia and the release of Sphagnum phenolic metabolites and suggest that Sphagnum-derived acids and minor phenolics play different roles in this interaction. This work provides new insight into the ecological role of Sphagnum phenolics by proposing a strong association with mycorrhizal colonization of shrubs.     

Ammonia Released by <Emphasis Type="Italic">Streptomyces aburaviensis</Emphasis> Induces Droplet Formation in <Emphasis Type="Italic">Streptomyces violaceoruber</Emphasis>

Streptomyces violaceoruber grown in co-culture with Streptomyces aburaviensis produces an about 17-fold higher volume of droplets on its aerial mycelium than in single-culture. Physical separation of the Streptomyces strains by either a plastic barrier or by a dialysis membrane, which allowed communication only by the exchange of volatile compounds or diffusible compounds in the medium, respectively, still resulted in enhanced droplet formation. The application of molecular sieves to bioassays resulted in the attenuation of the droplet-inducing effect of S. aburaviensis indicating the absorption of the compound. ¹H-NMR analysis of molecular-sieve extracts and the selective indophenol-blue reaction revealed that the volatile droplet-inducing compound is ammonia. The external supply of ammonia in biologically relevant concentrations of ≥8 mM enhanced droplet formation in S. violaceoruber in a similar way to S. aburaviensis. Ammonia appears to trigger droplet production in many Streptomyces strains because four out of six Streptomyces strains exposed to ammonia exhibited induced droplet production.     

Identification of Crepenynic Acid in the Seed Oil of <Emphasis Type="Italic">Atractylodes lancea</Emphasis> and <Emphasis Type="Italic">A. macrocephala</Emphasis>

Atractylodes rhizome is widely used in traditional Chinese herbal medicine. Although the chemical composition of the root has been studied in detail, the oil content and fatty acid composition of the seeds of Atractylodes species have not been reported. Fatty acyl composition of seeds from Atractylodes lancea and A. macrocephala was determined by gas chromatography and mass spectrometry of fatty acid methyl esters and 3-pyridylcarbinol esters. The predominant fatty acid in the seeds of both species was linolenic acid, but the unusual acetylenic fatty acid, crepenynic acid (cis-9-octadecen-12-ynoic acid), was also observed at levels of 18% in A. lancea and 13–15% in A. macrocephala. Fatty acid content was 24% for the samples of A. lancea and 16–17% for samples from A. macrocephala. sn-1,3 regioselective lipase digestion of seed lipids revealed that crepenynic acid was absent from the sn-2 position of the seed triacylglycerol. Crepenynic acid was also found in the seed oil of Jurinea mollis at 24% and was not present in the sn-2 position of the TAG. A contrasting distribution of crepenynic acid was found in the oil of Crepis rubra, suggesting differences in crepenynic acid synthesis or TAG assembly between these species.     

The Role of the Glucosinolate-Myrosinase System in Mediating Greater Resistance of <Emphasis Type="Italic">Barbarea verna</Emphasis> than <Emphasis Type="Italic">B. vulgaris</Emphasis> to <Emphasis Type="Italic">Mamestra brassicae</Emphasis> Larvae

We investigated the influences of two structurally similar glucosinolates, phenethylglucosinolate (gluconasturtiin, NAS) and its (S)-2-hydroxyl derivative glucobarbarin (BAR), as well as their hydrolysis products on larvae of the generalist Mamestra brassicae (Lepidoptera: Noctuidae). Previous results suggested a higher defensive activity of BAR than NAS based on resistance toward M. brassicae larvae of natural plant genotypes of Barbarea vulgaris R. Br. (Brassicaceae) dominated by BAR. In the present study, the hypothesis of a higher defensive activity of BAR than NAS was tested by comparing two Barbarea species similarly dominated either by BAR or by NAS and by testing effects of isolated BAR and NAS on larval survival and feeding preferences. Larvae reared on leaf disks of B. verna (Mill.) Asch. had a lower survival than those reared on B. vulgaris P- and G-chemotypes. Leaves of B. verna were dominated by NAS, whereas B. vulgaris chemotypes were dominated by BAR or its epimer. In addition, B. verna leaves showed a threefold higher activity of the glucosinolate-activating myrosinase enzymes. The main product of NAS from breakdown by endogenous enzymes including myrosinases (“autolysis”) in B. verna leaves was phenethyl isothiocyanate, while the main products of BAR in autolyzed B. vulgaris leaves were a cyclized isothiocyanate product, namely an oxazolidine-2-thione, and a downstream metabolite, an oxazolidin-2-one. The glucosinolates BAR and NAS were isolated and offered to larvae on disks of cabbage. Both glucosinolates exerted similar negative effects on larval survival but effects of NAS tended to be more detrimental. Low concentrations of BAR, but not of NAS, stimulated larval feeding, whereas high BAR concentrations acted deterrent. NAS only tended to be deterrent at the highest concentration, but the difference was not significant. Recoveries of NAS and BAR on cabbage leaf disks were similar, and when hydrolyzed by mechanical leaf damage, the same isothiocyanate-type products as in Barbarea plants were formed with further conversion of BAR to cyclic products, (R)-5-phenyloxazolidine-2-thione [(R)-barbarin] and (R)-5-phenyloxazolidin-2-one [(R)-resedine]. We conclude that a previously proposed generally higher defensive activity of BAR than NAS to M. brassicae larvae could not be confirmed. Indeed, the higher resistance of NAS-containing B. verna plants may be due to a combined effect of rather high concentrations of NAS and a relatively high myrosinase activity or other plant traits not investigated yet.     

Sexual Deception in the <Emphasis Type="Italic">Eucera</Emphasis>-Pollinated <Emphasis Type="Italic">Ophrys leochroma</Emphasis>: A Chemical Intermediate between Wasp- and <Emphasis Type="Italic">Andrena-</Emphasis>Pollinated Species

Ophrys flowers mimic sex pheromones of attractive females of their pollinators and attract males, which attempt to copulate with the flower and thereby pollinate it. Virgin females and orchid flowers are known to use the same chemical compounds in order to attract males. The composition of the sex pheromone and its floral analogue, however, vary between pollinator genera. Wasp-pollinated Ophrys species attract their pollinators by using polar hydroxy acids, whereas Andrena-pollinated species use a mixture of non-polar hydrocarbons. The phylogeny of Ophrys shows that its evolution was marked by episodes of rapid diversification coinciding with shifts to different pollinator groups: from wasps to Eucera and consequently to Andrena and other bees. To gain further insights, we studied pollinator attraction in O. leochroma in the context of intra- and inter-generic pollinator shifts, radiation, and diversification in the genus Ophrys. Our model species, O. leochroma, is pollinated by Eucera kullenbergi males and lies in the phylogeny between the wasp and Andrena-pollinated species; therefore, it is a remarkable point to understand pollinator shifts. We collected surface extracts of attractive E. kullenbergi females and labellum extracts of O. leochroma and analyzed them by using gas chromatography with electroantennographic detection (GC-EAD) and gas chromatography coupled with mass spectrometry (GC-MS). We also performed field bioassays. Our results show that O. leochroma mimics the sex pheromone of its pollinator’s female by using aldehydes, alcohols, fatty acids, and non-polar compounds (hydrocarbons). Therefore, in terms of the chemistry of pollinator attraction, Eucera-pollinated Ophrys species might represent an intermediate stage between wasp- and Andrena-pollinated orchid species.     

Efficient production of <Emphasis Type="SmallCaps">d</Emphasis>-1,2,4-butanetriol from <Emphasis Type="SmallCaps">d</Emphasis>-xylose by engineered <Emphasis Type="Italic">Escherichia coli</Emphasis> whole-cell biocatalysts

We have developed a whole-cell bioconversion system for the production of d-1,2,4-butanetriol (BT) from renewable biomass. A plasmid pETduet-xylB-yjhG-T7-adhP-T7-mdlC was constructed and transformed to Escherichia coli BL21(DE3) to obtain the whole cells of E. coli BL21-XYMA capable of bioconversion d-xylose to BT. Then, the factors including carbon sources, nitrogen sources, metal ions, and culture conditions (pH, temperature, IPTG) were identified, and their effects on the whole-cell activity for BT production were investigated. To obtain the highest whole-cell activity, the optimal cultivation parameters are: 15 g·L^–1 yeast extract, 5 g·L^–1 sucrose, 3 g·L^–1 KH₂PO₄, 5 g·L^–1 NaCl, 3 g·L^–1 NH₄Cl, 0.25 g·L^–1 MgSO₄·7H₂O and 1 mL·L^–1 the mixture of trace elements. With the optimized whole cells of E. coli BL21-XYMA, 60 g·L^–1 of xylose was converted to 28 g·L^–1 BT with a molar yield of 66 %, which is higher than those reported in the biotechnological system.

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Sexual Isolation and Cuticular Hydrocarbon Differences between <Emphasis Type="Italic">Drosophila santomea</Emphasis> and <Emphasis Type="Italic">Drosophila yakuba</Emphasis>

Drosophila santomea and Drosophila yakuba are two sister species inhabiting Saõ Tomé island. Previous studies showed that both species display strong reproductive isolation, although they can produce a few viable hybrids. Our study tried to understand the mechanism of this ethological isolation between two allopatric strains. A strong sexual isolation was confirmed, with a marked asymmetry. Comparisons of latency times to either courtship or copulation suggest that males do not discriminate females, whereas D. yakuba females, but not D. santomea females, accept their homospecifics more quickly. Cuticular hydrocarbon compositions of both species and sexes were also established with gas chromatography (GC) and GC/mass spectrometry analysis. All have (Z)-7-tricosene as their major compound. There are several quantitative differences between species for few minor compounds. The largest difference concerns n-heneicosane, which is more abundant in D. santomea than in D. yakuba flies (up to seven times more between males). A similar quantitative difference was also found in a pair of sympatric strains. Furthermore, D. yakuba males artificially perfumed with n-heneicosane were discriminated negatively by D. yakuba females, suggesting a role for this compound in the sexual isolation between these two species.     

Electrospun Micro/Nanofibers as Controlled Release Systems for Pheromones of <Emphasis Type="Italic">Bactrocera oleae</Emphasis> and <Emphasis Type="Italic">Prays oleae</Emphasis>

New systems for the controlled release of 1,7-dioxaspiro[5.5]undecane and (Z)-7-tetradecenal, the sex pheromones of olive fruit fly, Bactrocera oleae, and olive moth, Prays oleae, respectively, were developed utilizing electrospun micro/nanofiber matrices from inexpensive, biodegradable polymers, namely polycaprolactone, cellulose acetate and polyhydroxybutyrate. The incorporation of the pheromones in 5, 10 and 20% w/w in the electrospinning polymer blends allowed for the production of fiber mats with variable loading levels and release rates, ensuring however in all cases the release of pheromones for more than 16 weeks. Laboratory bioassays and field trapping tests showed that the fiber mats obtained from electrospinning of polyhydroxybutyrate solution containing 5% w/w 1,7-dioxaspiro[5.5]undecane and polycaprolactone solution containing 5% w/w (Z)-7-tetradecenal were almost twice as effective in attracting B. oleae and P. oleae males, respectively, in comparison to the positive controls used.     

Modifying the Alkylglucosinolate Profile in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> Alters the Tritrophic Interaction with the Herbivore <Emphasis Type="Italic">Brevicoryne brassicae</Emphasis> and Parasitoid <Emphasis Type="Italic">Diaeretiella rapae</Emphasis>

Arabidopsis thaliana was used as an experimental model plant to investigate a tritrophic interaction between the plant, a specialist aphid herbivore, Brevicoryne brassicae, and its natural enemy, the parasitoid Diaeretiella rapae. The A. thaliana ecotype Col-5 was transformed with a functional 2-oxoglutarate dependent dioxygenase (BniGSL-ALK) that converts 3-methylsulfinylpropylglucosinolate and 4-methylsulfinylbutylglucosinolate to 2-propenylglucosinolate and 3-butenylglucosinolate, respectively. This transformation results in a change in the glucosinolate hydrolysis profile where 3-butenylisothiocyanate, 2-propenylisothiocyanate and 5-vinyloxazolidine-2-thione are produced in contrast to the wild-type plant where 4-methylsulfinylbutylisothiocyanate is the main product. Performance of B. brassicae was affected negatively by transforming Col-5 with BniGSL-ALK in terms of mean relative growth rates. In a series of behavioral bioassays, naïve D. rapae females were able to discriminate between B. brassicae infested and uninfested Col-5 plants transformed with BniGSL-ALK, with parasitoids showing a preference for B. brassicae infested plants. By contrast, naïve D. rapae females were unable to discriminate between aphid infested and uninfested Col-5 plants. Subsequent air entrainments of B. brassicae infested Col-5 plants transformed with BniGSL-ALK further confirmed the presence of 3-butenylisothiocyanate in the headspace. By contrast, no glucosinolate hydrolysis products were recorded from similarly infested Col-5 plants.     

Production of rhamnolipids-producing enzymes of <Emphasis Type="Italic">Pseudomonas</Emphasis> in <Emphasis Type="Italic">E. coli</Emphasis> and structural characterization

Rhamnolipids are a class of biosurfactants that have a great potential to be used in industries. Five proteins/enzymes, namely RhlA, RhlB, RhlC, RhlG and RhlI, are critical for the production of rhamnolipids in Pseudomonas aeruginosa. Four of the 5 proteins except RhlC were successfully over-expressed in E. coli and three of them (RhlA, RhlB and RhlI) were purified and obtained in milligram quantities. The purified proteins were shown to be folded in solution. Homology models were built for RhlA, RhlB and RhlI. These results lay a basis for further structural and functional characterization of these proteins in vitro to favor the construction of super strains for rhamnolipids production.

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<Emphasis Type="Italic">cis</Emphasis>-Jasmone Elicits Aphid-Induced Stress Signalling in Potatoes

Elicitation of plant defense signaling that results in altered emission of volatile organic compounds (VOCs) offers opportunities for protecting plants against arthropod pests. In this study, we treated potato, Solanum tuberosum L., with the plant defense elicitor cis-jasmone (CJ), which induces the emission of defense VOCs and thus affects the behavior of herbivores. Using chemical analysis, electrophysiological and behavioral assays with the potato-feeding aphid Macrosiphum euphorbiae, we showed that CJ treatment substantially increased the emission of defense VOCs from potatoes compared to no treatment. Coupled GC-electroantennogram (GC-EAG) recordings from the antennae of M. euphorbiae showed robust responses to 14 compounds present in induced VOCs, suggesting their behavioral role in potato/aphid interactions. Plants treated with CJ and then challenged with M. euphorbiae were most repellent to alate M. euphorbiae. Principal component analysis (PCA) of VOC collections suggested that (E)-2-hexenal, (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), (E)-β-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate (MeSA), CJ, and methyl benzoate (MeBA) were the main VOCs contributing to aphid behavioral responses, and that production of TMTT, (E)-β-farnesene, CJ, and DMNT correlated most strongly with aphid repellency. Our findings confirm that CJ can enhance potato defense against aphids by inducing production of VOCs involved in aphid-induced signalling.     

Stingless Bees: Chemical Differences and Potential Functions in <Emphasis Type="Italic">Nannotrigona testaceicornis</Emphasis> and <Emphasis Type="Italic">Plebeia droryana</Emphasis> Males and Workers

Cuticular wax, abdominal and cephalic extracts of foraging workers and males of Nannotrigona testaceicornis and Plebeia droryana, from the “Aretuzina” farm in São Simão, SP, Brazil, were analyzed by GC-MS. The principal constituents were hydrocarbons, terpenes, aldehydes, esters, steroids, alcohols, and fatty acids. Interspecific differences for both cuticular wax and cephalic extracts were found. The composition of cuticular wax and cephalic extracts was similar at the intraspecific level, with minor component differences between males and workers. Abdominal extracts differentiated sexes (male and worker) at the intraspecific and interspecific levels. The main chemical components in abdominal extracts of N. testaceicornis workers and males were geranylgeranyl acetate and (Z)-9-nonacosene, respectively. The principal components of abdominal extracts from P. droryana workers and males were tetradecanal and unsaturated fatty acids (linoleic and linolenic acids), respectively. A secondary alcohol, (S)-2-nonanol, was detected in Plebeia droryana males only, but not in workers. Preliminary field experiments showed that (S)-(+)-2-heptanol and (S)-(+)-2-heptanol/ (S)-(+)-2-nonanol (1:1) attracted workers of P. droryana, N. testaceicornis, and Frieseomelitta silvestrii. However, males did not respond suggesting that these compounds do not function as alarm or recruitment pheromones . In addition, racemic mixtures were inactive.     

Fatal Attraction: <Emphasis Type="Italic">Ricinus communis</Emphasis> Provides an Attractive but Risky Mating Site for <Emphasis Type="Italic">Holotrichia parallela</Emphasis> Beetles

The castor bean, Ricinus communis L., is a non-host plant for the large black chafer, Holotrichia parallela Motschulsky (Coleoptera: Scarabaeidae). In laboratory bioassays we found that this plant was no less attractive than the main host plant (peanut, Arachis hypogaea) and three food plant species: velvetleaf (Abutilon theophrasti), the glossy privet (Ligustrum lucidum), and the Siberian elm (Ulmus pumila). In field trapping experiments a Soxhlet extract of castor bean leaves caught more beetles than the optimal sex lure blend [(R)-(?)-linalool and (L)-isoleucine methyl ester blended in a ratio of 1:4], compared at equal doses (500 μl), and laboratory bioassays indicated that a castor bean plant could enhance the attractiveness of different blend ratios of sex lures. Olfactometer bioassays showed that males prefer volatiles emitted from different combinations of castor bean plant extracts and a signaling female over a female alone. In the presence of castor bean plants copulation rates of H. parallela were highest among all test environments both in laboratory bioassays (60%) and in field tests (70%). This study, combined with our previous observation of the feeding behavior of H. parallela adults on castor bean leaves, suggests that castor bean plants may provide an attractive but risky mating site for H. parallela beetles. The enhancement of male mate-location and copulation rate in the presence of castor bean plants can balance its paralytic effects on H. parallela after intake of potential toxins contained in its leaves.     

An Attractant of the Aphidophagous Gall Midge <Emphasis Type="Italic">Aphidoletes aphidimyza</Emphasis> From Honeydew of <Emphasis Type="Italic">Aphis gossypii</Emphasis>

Many natural enemies of insects use honeydew as a volatile cue to locate hosts or prey, as an oviposition stimulant, and as an arrestant for foraging. The aphidophagous gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) has predacious larval stages and can be used to control aphid populations, especially in greenhouses. Previous studies have shown that the honeydew, excreted by the aphid Myzus persicae, attracts A. aphidimyza, but the crucial attractants have not been identified. Using an olfactometer, we studied behavioral responses of female A. aphidimyza to volatiles emitted from honeydew excreted by the aphid Aphis gossypii on eggplants. The volatiles attracted female midges and induced oviposition. Moreover, using gas chromatography coupled with mass spectrometry (GC/MS), we identified phenylacetaldehyde as the attractant compound in the honeydew, although it did not induce oviposition in olfactometer experiments.     

<Emphasis Type="Italic">trans</Emphasis>-10,<Emphasis Type="Italic">cis</Emphasis>-12 Conjugated Linoleic Acid Enhances Endurance Capacity by Increasing Fatty Acid Oxidation and Reducing Glycogen Utilization in Mice

The supplementation of conjugated linoleic acid (CLA) has been shown to improve endurance by enhancing fat oxidation during exercise in rodents and humans. This study was designed to investigate the isomer-specific effects of CLA on endurance capacity and energy metabolism in mice during exercise. Male 129Sv/J mice were divided into three dietary groups and fed treatment diet for 6 weeks; control, 0.5 % cis-9,trans-11 (c9,t11) CLA, or 0.5 % trans-10,cis-12 (t10,c12) CLA. Dietary t10,c12 CLA induced a significant increase in maximum running time and distance until exhaustion with a dramatic reduction of total adipose depots compared to a control group, but there were no significant changes in endurance with the c9,t11 CLA treatment. Serum triacylglycerol and non-esterified fatty acid concentrations were significantly lower in the t10,c12 fed mice after exercise compared to control and the c9,t11 CLA fed-animals. Glycogen contents in livers of the t10,c12 fed-mice were higher than those in control mice, concomitant with reduction of serum l-lactate level. There were no differences in non-exercise physical activity among all treatment groups. In addition, the mRNA expression levels of carnitine palmitoyl transferase 1β, uncoupling protein 2 and peroxisome proliferator-activated receptor δ (PPARδ) in skeletal muscle during exercise were significantly up-regulated by the t10,c12 CLA but not the c9,t11 CLA. These results suggest that the t10,c12 CLA is responsible for improving endurance exercise capacity by promoting fat oxidation with a reduction of the consumption of stored liver glycogen, potentially mediated via PPARδ dependent mechanisms.     

Seasonal Changes Affect Root Prunasin Concentration in <Emphasis Type="Italic">Prunus serotina</Emphasis> and Override Species Interactions between <Emphasis Type="Italic">P. serotina</Emphasis> and <Emphasis Type="Italic">Quercus petraea</Emphasis>

The allocation of resources to chemical defense can decrease plant growth and photosynthesis. Prunasin is a cyanogenic glycoside known for its role in defense against herbivores and other plants. In the present study, fluctuations of prunasin concentrations in roots of Prunus serotina seedlings were hypothesized to be: (1) dependent on light, air temperature, and humidity; (2) affected by competition between Prunus serotina and Quercus petraea seedlings, with mulching with Prunus serotina leaves; (3) connected with optimal allocation of resources. For the first time, we determined prunasin concentration in roots on several occasions during the vegetative season. The results indicate that seasonal changes have more pronounced effects on prunasin concentration than light regime and interspecific competition. Prunus serotina invested more nitrogen in the synthesis of prunasin under highly restricted light conditions than in higher light environments. In full sun, prunasin in roots of Prunus serotina growing in a monoculture was correlated with growth and photosynthesis, whereas these relationships were not found when interspecific competition with mulching was a factor. The study demonstrates that prunasin concentration in Prunus serotina roots is the result of species-specific adaptation, light and temperature conditions, ontogenetic shift, and, to a lesser extent, interspecific plant-plant interactions.     

Naphthoquinone Metabolites Produced by <Emphasis Type="Italic">Monacrosporium ambrosium</Emphasis>, the Ectosymbiotic Fungus of Tea Shot-Hole Borer, <Emphasis Type="Italic">Euwallacea fornicatus,</Emphasis> in Stems of Tea, <Emphasis Type="Italic">Camellia sinensis</Emphasis>

The tea shot-hole borer beetle (TSHB, Euwallacea fornicatus) causes serious damage in plantations of tea, Camellia sinensis var. assamica, in Sri Lanka and South India. TSHB is found in symbiotic association with the ambrosia fungus, Monacrosporium ambrosium (syn. Fusarium ambrosium), in galleries located within stems of tea bushes. M. ambrosium is known to be the sole food source of TSHB. Six naphthoquinones produced during spore germination in a laboratory culture broth of M. ambrosium were isolated and identified as dihydroanhydrojavanicin, anhydrojavanicin, javanicin, 5,8-dihydroxy-2-methyl-3-(2-oxopropyl)naphthalene-1,4-dione, anhydrofusarubin and solaniol. Chloroform extracts of tea stems with red-colored galleries occupied by TSHB contained UV active compounds similar to the above naphthoquinones. Laboratory assays demonstrated that the combined ethyl acetate extracts of the fungal culture broth and mycelium inhibited the growth of endophytic fungi Pestalotiopsis camelliae and Phoma multirostrata, which were also isolated from tea stems. Thus, pigmented naphthoquinones secreted by M. ambrosium during spore germination may prevent other fungi from invading TSHB galleries in tea stems. The antifungal nature of the naphthoquinone extract suggests that it protects the habitat of TSHB. We propose that the TSHB fungal ectosymbiont M. ambrosium provides not only the food and sterol skeleton necessary for the development of the beetle during its larval stages, but also serves as a producer of fungal inhibitors that help to preserve the purity of the fungal garden of TSHB.     

Cuticular Hydrocarbon Cues Are Used for Host Acceptance by <Emphasis Type="Italic">Pseudacteon</Emphasis> spp. Phorid Flies that Attack <Emphasis Type="Italic">Azteca sericeasur</Emphasis> Ants

Parasitoids often use complex cues to identify suitable hosts in their environment. Phorid fly parasitoids that develop on one or a few host species often use multiple cues, ranging from general to highly specific, to home in on an appropriate host. Here, we describe the hierarchy of cues that Pseudacteon phorid flies use to identify Azteca ant hosts. We show, through behavioral observations in the field, that phorid flies are attracted to two cryptic Azteca species, but only attack Azteca sericeasur (Hymenoptera: Formicidae: Dolichoderinae). To test whether the phorid flies use cuticular hydrocarbons (CHCs) to distinguish between the two Azteca taxa, we first documented and compared cuticular hydrocarbons of the two Azteca taxa using gas chromatography/mass spectrometry. Then, using cuticular hydrocarbon-transfer experiments with live ants, we characterized the cuticular hydrocarbons of A. sericeasur as a short-range, host location cue used by P. lasciniosus (Diptera: Phoridae) to locate the ants.     

Interspecific Cross-Attraction between the South American Cerambycid Beetles <Emphasis Type="Italic">Cotyclytus curvatus</Emphasis> and <Emphasis Type="Italic">Megacyllene acuta</Emphasis> is Averted by Minor Pheromone Components

During field screening trials conducted in Brazil in 2015, adults of both sexes of the cerambycid beetles Cotyclytus curvatus (Germar) and Megacyllene acuta (Germar) (subfamily Cerambycinae, tribe Clytini) were significantly attracted to racemic 3-hydroxyhexan-2-one and racemic 2-methylbutan-1-ol, chemicals which previously have been identified as male-produced aggregation-sex pheromones of a number of cerambycid species endemic to other continents. Subsequent analyses of samples of beetle-produced volatiles revealed that males of C. curvatus sex-specifically produce only (R)-3-hydroxyhexan-2-one, whereas males of M. acuta produce the same compound along with lesser amounts of (2S,3S)-2,3-hexanediol and (S)-2-methylbutan-1-ol. Follow-up field trials showed that both sexes of both species were attracted to synthetic reconstructions of their respective pheromones, confirming that males produce aggregation-sex pheromones. The minor pheromone components of M. acuta, (S)-2-methylbutan-1-ol and (2S,3S)-2,3-hexanediol, synergized attraction of that species, but antagonized attraction of C. curvatus to (R)-3-hydroxyhexan-2-one. Beetles of other cerambycine species also were attracted in significant numbers, including Chrysoprasis linearis Bates, Cotyclytus dorsalis (Laporte & Gory), and Megacyllene falsa (Chevrolat). Our results provide further evidence that 3-hydroxyhexan-2-one is a major component of attractant pheromones of numerous cerambycine species world-wide. Our results also highlight our increasing understanding of the crucial role of minor pheromone components in imparting species specificity to cerambycid pheromone blends, as is known to occur in numerous species in other insect families.