Field catches of Oxythyrea cinctella using visual and olfactory cues

Diurnal flower‐visiting scarabs (Coleoptera: Scarabaeidae, Cetoniinae) use visual and olfactory stimuli when locating possible feeding sites. In field trapping experiments in Turkey, testing different colours and floral volatile compounds, a combination of fluorescent yellow colour and a blend of 2‐phenylethanol and (±)‐lavandulol leads to the highest number of Oxythyrea cinctella (Schaum) being caught. Trap catches of O. cinctella with respect to the individually presented visual or olfactory cues are significantly lower than to a combination of the two. The closely‐related O. funesta, a sibling species in the Oxythyrea genus, is also known to be caught by the same colour‐volatile combination. When applied together in a high capture‐capacity trap, the fluorescent yellow colour and the binary floral odour blend may provide a suitable means of monitoring population changes of O. cinctella, which indicates their potential use in agriculture.     

Response of garden chafer, Phyllopertha horticola, to plant volatiles: from screening to application

Field tests were performed on a golf course and in an apple orchard to screen synthetic plant volatiles with respect to their attractiveness for the garden chafer, Phyllopertha horticola L. (Coleoptera: Scarabaeidae), and to investigate the possible application of plant volatiles for garden chafer control. The chemicals tested were green leaf volatiles (GLV), terpenoids, and phenylpropanoids. Funnel traps baited with the GLV (Z)‐3‐hexen‐1‐ol, 1‐hexanol (Z)‐3‐hexenal, and hexanal captured more P. horticola than unbaited controls. Furthermore, traps baited with all tested floral terpenoids (i.e., geraniol, geranyl acetate, citronellol, linalool, and nerol) and phenylpropanoids (i.e., eugenol, anethol, isoeugenol, eugenyl acetate, and isoeugenyl acetate) captured more garden chafers than controls. Different dispenser types loaded once with a mixture of (Z)‐3‐hexen‐1‐ol (50%), geraniol (11.5%), eugenol (27%), and 2‐phenylethyl propionate (11.5%) attracted P. horticola over a whole flight season. A commercially available membrane dispenser had the best properties, combining the highest number of captured beetles with a low release rate. A simple modification of the trap design, i.e., a reduction of the funnel outlet diameter, significantly reduced the capture of beneficial non‐target insects (Apoidea), without influencing the number of captured garden chafers. A mass trapping experiment in the apple orchard revealed that the use of attractant traps significantly reduced the percentage of apples disfigured by feeding holes of adult garden chafers (control area: 18.9%, test area: 11.6%). The possible application of synthetic plant volatiles in mass trapping and monitoring approaches for garden chafer control is discussed.     

Disruption of trans‐pityol‐mediated attraction by racemic trans‐conophthorin in twig beetle Pityophthorus pubescens

Twig beetle Pityophthorus pubescens (Coleoptera: Curculionidae: Scolytinae) has been previously associated with the Fusarium circinatum (Hypocreales: Nectriaceae), the pathogen causing pitch canker disease, in P. radiata stands of the Basque Country (Northern Spain). Laboratory and field studies were conducted to evaluate the response of the insect to the racemic mixture of the spiroacetal trans‐7‐methyl‐1,6‐dioxaspiro[4.5]decane, also known as conophthorin. In walking bioassays, addition of 10 and 100 ng of racemic trans‐conophthorin to 1 ng of (±)‐trans‐pityol elicited a negative response in males, whereas females did not show any significant preference. Catches of males in attractant‐baited traps were strongly reduced by racemic trans‐conophthorin at all release rates tested (0.5, 1.0, 1.5 and 2.0 mg/day). In contrast, catches of females were not affected by any of the (±)‐trans‐conophthorin release rate.     

Attraction of garden chafer, Phyllopertha horticola, to floral Japanese beetle lure

Field experiments using funnel traps were performed on a golf course to investigate the attractiveness of a floral Japanese beetle lure for adults of the garden chafer, Phyllopertha horticola, a common European turf pest. Traps baited with 10 mg of the floral lure consisting of phenylethyl propionate + eugenol + geraniol (3 : 7 : 3) captured more adult garden chafers of both sexes than non‐baited control traps. In contrast, 1,3‐dimethyl‐2,4‐(1H, 3H)‐quinazolinedione, the sex pheromone of the closely related pale‐brown chafer P. diversa, neither influenced alone nor in combination with the floral lure the behaviour of adult garden chafers. The results suggest that the floral Japanese beetle lure might be used for monitoring or control of P. horticola.     

Cyclolavandulyl butyrate: an attractant for a mealybug parasitoid, <Emphasis Type="Italic">Anagyrus</Emphasis><Emphasis Type="Italic">sawadai</Emphasis> (Hymenoptera: Encyrtidae)

In this study, we discovered and isolated an attractant for a mealybug-parasitic wasp Anagyrus sawadai from an esterification product prepared with commercialized lavandulol (2-isopropenyl-5-methyl-4-hexen-1-ol) and butyryl chloride. Using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy, we determined the structure of the compound to be (2,4,4-trimethyl-2-cyclohexenyl)methyl butyrate (cyclolavandulyl butyrate). This is a novel compound as far as we know, although the alcohol moiety has been known as a cyclization product from lavandulol. Cyclolavandulyl butyrate has two enantiomers, and the (−)-isomer, which is suggested to have S configuration, showed higher attractiveness. A potential use for the A. sawadai attractant for mealybug management in agricultural fields is discussed.     

Innate attractant for long‐tongued bumblebee,Bombus diversus diversus in floral scent of bumblebee‐pollinated epiparasitic plant,Monotropastrum humile (Ericaceae)

The epiparasitic plant Monotropastrum humile (D. Don) Hara is pollinated by workers of the long‐tongued bumblebee, Bombus diversus diversus (Smith). The interaction between the floral scents of this plant and bumblebee was investigated using electrophysiological and behavioral techniques. Three components (linalool, α‐terpineol and geraniol) elicited strong responses in antennae from B. d. diversus workers and are innate attractants, suggesting floral scents play an important role in attracting these pollinators and successful pollination.     

Gill area and dimensions of gilthead sea bream Sparus aurata L.

Detailed measurements of gill area and constituent variables (total filament length, lamellar frequency and bilateral area) were performed on both hemibranchs of all eight arches in six specimens of gilthead sea bream Sparus aurata (mean ±s.e . 49·9 ± 0·2 g). Shrinkage was also quantified and results were corrected accordingly. Filament number decreased from the first to the fourth gill arch, and average bilateral area of secondary lamellae was higher in the second and third arches. Total and mean filament length, total number of secondary lamellae and total gill area (A_TG) were lower in posterior than in anterior hemibranchs of the second, third and fourth gill arches; while the opposite was observed for the first arch. Lamellar frequency was increased in posterior hemibranchs of all arches compared to that in anterior hemibranchs, especially at the fourth arch. Comparison of the actually measured A_TG and constituent variables with estimates revealed that the third gill arch is the most representative for appropriate measurements and that any of its components (even one hemibranch) approximates the best A_TG (within the range of 0·2–4·3%, P > 0·05) and related dimensions. Consequently, necessary measurements were restricted to the posterior hemibranch of the third gill arch, and A_TG and dimensions (y) were estimated in 21 specimens (23·5–217·6 g) and correlated to body mass (M) according to the allometric equation y = aM^b. As fish increased in size, A_TG (b= 0·664), total (b= 0·425) and mean (b= 0·323) filament length, total number of filaments (b= 0·103) and secondary lamellae (b= 0·377), as well as average lamellar bilateral area (b= 0·288), increased, while the opposite was observed for lamellar frequency (b=?0·049) and mass‐specific area (b=?0·336). Data obtained are discussed in relation to S. aurata activity and living ethology.     

An aggregation attractant for the sugar-beet weevil, Bothynoderes punctiventris

During our screening studies, attractiveness of a ternary mixture of synthetic Grandlure I [racemic cis‐1‐methyl‐2‐(1‐methylenethenyl)‐cyclobutane ethanol], Grandlure II [(Z)‐2‐(3,3‐dimethyl)cyclohexylidene ethanol], and Grandlure III–IV [(Z)‐ and (E)‐2‐ochtodenal; (Z)‐ and (E)‐(3,3‐dimethyl)cyclohexylidene acetaldehyde] for the sugar‐beet weevil, Bothynoderes punctiventris Germar (Coleoptera: Curculionidae), was observed in field‐trapping tests at several sites in Hungary and Serbia. The mixture attracted both males and females. Later tests revealed that of the components in the ternary mixture, only Grandlure III–IV were responsible for attraction, and the addition of Grandlures I or II in varying percentages had no influence on trap captures. Traps baited with 50–50 000 µg of Grandlure III–IV on rubber or polyethylene dispensers yielded high catches of weevils. When testing synthetic samples enriched in the respective geometrical isomer, Grandlure IV had a tendency of catching more weevils, but differences were not significant from lower catches by a 1:1 Z:E blend or Grandlure III. In gas chromatography–flame ionization detection/electroantennographic detection studies, antennae of both female and male weevils were more responsive to the (E)‐ than to the (Z)‐isomer suggesting a more important role for Grandlure IV. Efforts to verify the presence of Grandlure III or IV in volatiles collected from either sex of live sugar‐beet weevils or body washings with pentane remained inconclusive. Traps baited with Grandlure III–IV can now be used as sensitive and powerful trapping tools in the control of the sugar‐beet weevil.     

Aggregation pheromone of the Oriental spruce engraver Pseudips orientalis

• 1 Volatiles from the hindgut extracts of males of the Oriental spruce engraver Pseudips orientalis (Wood & Yin) (Coleoptera: Curculionidae, Scolytinae) of different phases of gallery development were analyzed by gas chromatography‐mass spectrometry‐flame ionization detection (GC‐MS/FID) with both polar and enantioselective columns.
• 2 GC‐MS/FID analyses showed that unmated males or males mated with one female produced approximately 95%‐(?)‐ipsenol and (?)‐cis‐verbenol as major components, as well as (?)‐trans‐verbenol, myrtenol, approximately 70%‐(+)‐ipsdienol and (?)‐verbenone as minor or trace components. The release of these male‐produced compounds was confirmed by GC analysis of an aeration sample of a P. orientalis‐infested spruce log. Mating reduced production of the male‐specific hindgut volatiles.
• 3 A field‐trapping bioassay in Qinghai, China, showed that a ternary blend containing two major components, 97%‐(?)‐ipsenol (i.e. close to naturally produced enantiomeric ratio) and (?)‐cis‐verbenol, plus a minor component (?)‐trans‐verbenol, caught significantly more P. orientalis beetles (♂: ♀ = 1: 2.7) compared with the unbaited control. Subtraction of (?)‐trans‐verbenol from the active ternary blend had no significant effect on trap catches. The addition of (±)‐ipsdienol (at 0.2 mg/day release) to the active ternary or binary blends significantly interrupted their trap catches. Replacing 97%‐(?)‐ipsenol with (±)‐ipsenol in the ternary blend significantly reduced trap catches to a level that was no different from the blank control.
• 4 Pseudips species were sister to all other Ipini genera in a phylogeny reconstructed with mitochondrial cytochrome oxidase I DNA data for 51 Ipini and outgroup species.
• 5 The results obtained suggest that the two major components, 95%‐(?)‐ipsenol and (?)‐cis‐verbenol (at approximately 4–5 : 1), produced by unmated fed males, are probably the primary aggregation pheromone components for P. orientalis. In light of the phylogeny, the use of terpenoid semiochemicals as pheromones probably occurred early in the evolution of Ipini and these semiochemical blends were subsequently modified in the process of speciation.

     

Differences in chemical,physical and sensory properties during shelf life assessment of wild and farmed gilthead sea bream (Sparus aurata,L.)

The aim of this study was to determine and compare differences in physical, chemical and sensory post‐mortem changes between wild (W) and farmed (F) gilthead sea bream (Sparus aurata). Ungutted fish were stored in ice from harvesting up to 20 days and freshness indicators were analyzed at regular intervals. Proximate composition of the samples differed in lipid (W = 0.86 ± 0.12; F = 4.18 ± 0.16) and moisture content (W = 79.12 ± 0.48; F = 74.50 ± 0.82). Data from sensory evaluation were described using linear regression models. Sensory schemes for cooked and raw fish were found to be suitable in establishing specific attribute deterioration and shelf life duration (W = 14 days; F = 17 days). Changes in pH and dielectric properties were influenced by differences in lipid content, while changes in total volatile base nitrogen and trimethylamine showed high correlation with sensory assessment and storage time, but stayed below the acceptance limit for human consumption (W : 24.47 mg TVB‐N/100 g and 4.14 mg TMA‐N/100 g; F : 26.18 mg TVB‐N/100 g and 3.84 mg TMA‐N/100 g), and thus were not reliable indicators of quality changes during storage in ice. Deterioration of flesh lipids, assessed by thiobarbituric acid index, differed between the samples, but presented no serious problem during storage time. In order to determine the importance of individual results, all obtained data were submitted to principal component analysis. Variations in sensory, physical and chemical assessment were described by PC1 (storage time); variations in lipid and moisture content were described by PC2 (capture grounds). A clear separation of the investigated samples, according to the storage time and capture grounds, was observed.     

Acidophilic granulocytes in the gills of gilthead seabream Sparus aurata: evidence for their responses to a natural infection by a copepod ectoparasite

Immunohistochemical and ultrastructural studies were conducted on the gills of gilthead seabream, Sparus aurata L., naturally infected with the copepod ectoparasite Ergasilus lizae (Krøyer, 1863) in order to assess pathology and the host immune cell response. Gills of 56 gilthead seabream were screened for ectoparasites; 36 specimens (64.3%) harbored E. lizae. Intensity of infection was 32.7±8.7 (mean ± SE). Pathological alterations to the gills of the host were more pronounced in close proximity to the copepod site of attachment. The parasite attached to the gills by means of its modified second antennae, occluded the arteries, provoked epithelial hyperplasia and hemorrhages and most often caused lamellar disruption. Numerous granular cells were encountered near the site of E. lizae attachment. In both infected and uninfected gills, the granular cells lay within the filaments and frequently occurred within the connective tissue inside and outside the blood vessels of the filaments. The type of granular cell was identified by immunohistochemical staining by using the monoclonal antibody G7 (mAb G7), which specifically recognizes acidophilic granulocytes (AGs) of S. aurata and with an anti-histamine antibody (as a marker for mast cells, MCs) on sections from 13 uninfected gills and 21 parasitized gills. The use of mAb G7 revealed that, in gills harboring copepods, the number of G7-positive cells (i.e., AGs; 32.9±3.9, mean number of cells per 45,000 μm² ± SE) was significantly higher than the density of the same cells in uninfected gills (15.3±3.8; ANOVA, P<0.05). Few histamine-positive granular cells (i.e., MCs) were found in the uninfected and parasitized gills. Here, we show, for the first time in S. aurata infected gills, that AGs rather than MCs are recruited and involved in the response to E. lizae infection in seabream.     

Essential oils as spatial repellents for the brown marmorated stink bug,Halyomorpha halys (Stål) (Hemiptera: Pentatomidae)

The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), native to Northeastern Asia, is a serious invasive pest in the United States, Canada, Switzerland, Germany and France. Several common essential oils and their compositions were tested against BMSBs as potential repellents. All the tested individual essential oils and a ternary oil blend showed significant repellency to both BMSB nymphs and adults. Clove oil, lemongrass oil, spearmint oil, ylang‐ylang oil, and the ternary oil mixture (clove, lemongrass and spearmint) almost completely blocked attraction of BMSBs to the stink bug attractant‐baited traps; whereas wintergreen oil, geranium oil, pennyroyal oil and rosemary oil resulted in 60–85% trap catch reductions. Over 20 BMSB antennally active compounds were identified from SPME headspace samples of the eight repellent essential oils using GC‐EAD and GC‐MS techniques. Among the synthetic EAD‐active compounds tested in the field, eugenol, l‐carvone, p/l‐menthone, pulegone, methyl salicylate, trans/cis‐citral, methyl benzoate and β‐caryophyllene significantly reduced trap catches of BMSBs by 72–99%; these compounds are likely responsible for the repellency of their corresponding essential oils. Surprisingly, a synthetic mixture of the predacious spined soldier bug (SSB) [Podisus maculiventris (Say)] aggregation pheromone (trans‐2‐hexenal, α‐terpineol and benzyl alcohol) also showed a significant inhibition of BMSB response to its attractants. These repellent essential oils and their active compounds, as well as the synthetic SSB pheromone, are potentially useful as part of an efficient, environmentally sound semiochemical‐based IPM programme to combat this serious invasive stink bug.     

Inheritance of a darkened caudal peduncle and yellow body coloration in the gilthead sea bream (Sparus aurata L.)

This study presents data on inheritance of a darkened caudal peduncle (ebony) and yellow body coloration (yellow) in the gilthead sea bream (Sparus aurata). Fifteen progeny groups, obtained by crossing fish with three color phenotypes and of known origin, were analyzed. Analyzes of segregation in F₁ progeny involving groups from parental crosses of wild‐type colored × wild‐type colored; ebony × ebony; yellow × yellow, showed that the parents produced the offspring only with the same phenotypes (true breeding). Crosses involving F₁ wild‐type colored parents (that resulted from crosses of wild‐type parents with either ebony or yellow fish) showed in their F₂ progeny groups of which their phenotypic segregations did not differ significantly from a 3 : 1 Mendelian ratio. The progeny of back‐cross of ebony × (F₁ wild‐type colored × ebony) showed phenotypic segregations that did not differ significantly from the 1 : 1 Mendelian ratio. Overall, the results of the crossing experiments demonstrated that, similar to albinism described in a number of aquacultured species, ebony and yellow body coloration in S. aurata are both due to a single recessive allele. However, the yellow mutation of a gene controlling yellow pigment synthesis affects the yellow color of the whole fish body, whereas the ebony mutation causes production of melanin only in a specific area of the fish body, resulting in the development of a black coloration of the caudal peduncle. Experiments to assess culture performance showed that the color genes controlling ebony and yellow coloration had significant detrimental pleiotropic effects on growth, survival and body shape. Color mutations in the gilthead sea bream may be used as models for the study of: (i) genetic and physiological mechanisms of sterility, (ii) stress and disease resistance, (iii) effects of heterosis, (iv) genetic polymorphism in populations, and (v) methods of genetic protection in selected sea bream strains as well as in experiments on chromosome set manipulation.     

Male and female Popillia quadriguttata (Fabricius) and Protaetia brevitarsis (Lewis) (Coleoptera: Scarabaeidae) response to Japanese beetle floral and pheromone lures

Popillia quadriguttata (Fabricius), and Protaetia brevitarsis (Lewis) adults were captured with Japanese beetle, Popillia japonica Newman, sex attractant and floral lures at Changchun, China during July–August 2012. The floral lure (phenethyl propionate:eugenol:geraniol, 3:7:3) was attractive to male and female P. quadriguttata (AV: 1.2 ± 0.9; 1.1 ± 0.3; total: 2.3 ± 0.8), and was similar in attraction to the combination of the sex attractant (SA) [(R, Z)-5-(1-decenyl) dihydro-2(3H)-furanone] plus the floral lure for male (1.60 ± 0.2), female (1.30 ± 1.1) and total captures (2.9 ± 3.0). However, the SA alone captured only males in much higher numbers than when combined with the floral lure (10.0 ± 6.4). In a separate earlier test, the greatest number of P. quadriguttata males (12.5 ± 3.0), female (12.2 ± 1.5) and total captures (24.7 ± 2.5) was in yellow, laboratory-made, bottle traps. The floral lure also attracted female Pro. brevitarsis (10.0 ± 3.4), while the SA attracted only few male beetles (1.0 ± 0.2). The combination SA + floral lure captured similar females (11.0 ± 2.0) and total (14.2 ± 2.2) Pro. brevitarsis as the floral lure alone. Two butterflies, Colias erate poliographus (Motschulsky) and Pieris rapae (Linnaeus), were also attracted to the floral lure. These studies indicate a potential for replacing pesticides by using the Japanese beetle lures for monitoring and control of several insects in China, and that they would be useful in monitoring and eradication of two potential scarab pests, P. quadriguttata and Pro. brevitaris, in the United States and Europe.     

Morphometric characterization of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa using computer-assisted spermatozoa analysis (ASMA)

As part of a larger study on sperm quality and cryopreservation methods, the present study characterized the head morphometry of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa, using both scanning electron microscopy (SEM) and computer‐assisted morphology analysis (ASMA). The latter method has been used rarely in fish and this is its first application on sharpsnout sea bream and gilthead sea bream spermatozoa. Results obtained using SEM are expensive and time‐consuming, while ASMA provides a faster and automated evaluation of morphometric parameters of spermatozoa head. For sharpsnout sea bream spermatozoa, similar head measurement values were obtained using both ASMA and SEM, having a mean ± standard error length of 2.57 ± 0.01 μm vs 2.54 ± 0.02 μm, width of 2.22 ± 0.02 μm vs 2.26 ± 0.04 μm, surface area of 4.44 ± 0.02 μm² vs 4.50 ± 0.04 μm² and perimeter of 7.70 ± 0.02 μm vs 7.73 ± 0.04 μm using ASMA and SEM, respectively. Although gilthead sea bream spermatozoa were found to be smaller than those of sharpsnout sea bream, spermatozoal head morphometry parameters were also found to be similar regardless of evaluation method, having a mean head length of 1.97 ± 0.01 μm vs 1.94 ± 0.02 μm, head width of 1.80 ± 0.01 μm vs 1.78 ± 0.02 μm, surface area of 3.16 ± 0.03 μm² vs 3.18 ± 0.06 μm² and perimeter of 6.52 ± 0.04 μm vs 6.56 ± 0.08 μm using ASMA and SEM, respectively. The results demonstrate that ASMA can be considered as a reliable technique for spermatozoal morphology analysis, and can be a useful tool for studies on fish spermatozoa, providing quick and objective results.     

β‐Ionone as putative semiochemical suggested by ligand binding on an odorant‐binding protein of Hylamorpha elegans and electroantennographic recordings

Currently, odorant‐binding proteins (OBPs) are considered the first filter for olfactory information for insects and constitute an interesting target for pest control. Thus, an OBP (HeleOBP) from the scarab beetle Hylamorpha elegans (Burmeister) was identified, and ligand‐binding assays based on fluorescence and in silico approaches were performed, followed by a simulated binding assay. Fluorescence binding assays showed slight binding for most of the ligands tested, including host‐plant volatiles. A high binding affinity was obtained for β‐ionone, a scarab beetle‐related compound. However, the binding of its analogue α‐ionone was weaker, although it is still considered good. On the other hand, through a three‐dimensional model of HeleOBP constructed by homology, molecular docking was carried out with 29 related ligands to the beetle. Results expressed as free binding energy and fit quality (FQ) indicated strong interactions of sesquiterpenes and terpenoids (α‐ and β‐ionone) with HeleOBP as well as some aromatic compounds. Residues such as His102, Tyr105 and Tyr113 seemed to participate in the interactions previously mentioned. Both in silico scores supported the experimental affinity for the strongest ligands. Therefore, the activity of α‐ionone, β‐ionone and 2‐phenyl acetaldehyde at antennal level was studied using electroantenography (EAG). Results showed that the three ligands are electrophysiologically active. However, an aliquot of β‐ionone (represented by 3.0 ng) elicited stronger EAG responses in antennae of males than of females. Finally, the role of these ligands as potential semiochemicals for H. elegans is discussed.     

Influence of environmental conditions on demand-feeding behaviour of gilthead seabream (Sparus aurata)

We studied the demand‐feeding behaviour was studied of gilthead seabream (Sparus aurata, L.) reared under either constant (25 ± 0.5°C, 12 : 12 L : D, control group) or natural (experimental group) temperature and photoperiod conditions during a period from winter to summer. Hourly demand‐feeding activity profiles were recorded using self‐feeding devices; these profiles showed that control group behaved entirely as a diurnal species, exhibiting no nightly activity and decreased demand rates in winter months. The experimental group did exhibit nightly activity (in incomplete darkness); this group also showed reduced demand rates in winter months, accompanied by a demand peak shift towards evening/night hours that followed the day's temperature peak of colder months.     

Volatile compounds with characteristic odour in moso‐bamboo stems (Phyllostachys pubescens Mazel ex Houz. De ehaie)

Introduction – Moso‐bamboo (Phyllostachys pubescens) is well known as an edible shoot in Asia, and the stems of moso‐bamboo are used as tableware due to its characteristic odour. Despite the pleasant odour of bamboo stems, no detailed analysis of the volatile compounds has been reported. Objective – To clarify the potent odourants contributing to the characteristic aroma of the bamboo, the aroma extract dilution analysis (AEDA) method was performed through gas chromatography olfactometry (GC‐O) analysis. In addition, relative flavour activity (RFA) was calculated, in which both the flavor dilution (FD) factor and weight percentage of each compound are involved. Results – Eighty‐nine compound in bamboo stems oil were identified by GC and GC‐MS. The main components of the oil were palmitic acid (16.5%), (E)‐nerolidol (10.2%) and indole (8.1%). In sensory analysis, 18 aroma‐active compounds were detected by aroma extract dilution analysis (AEDA). The most intense aroma‐active compounds were eugenol (sweet, clove‐like, green) and (E)‐2‐nonenal (green). Conclusion – The results of the sniffing test, RFA and FD factor indicated that (E)‐2‐nonenal and eugenol were estimated to have a bamboo‐like aroma, and aldehyde compounds, such as a phenylacetaldehyde (floral) and C9–C10 unsaturated aldehydes, make the aroma of bamboo. Copyright © 2010 John Wiley & Sons, Ltd.     

Temporal variation of flower scent in Silene otites (Caryophyllaceae): a species with a mixed pollination system

Floral scent composition and emission are often related to olfactory abilities, preferences and activity times of pollinating agents. However, most studies have focused on species with one pollinator type, and little is known about species with mixed pollination systems. We investigated the temporal variation in flower visitor activity and flower scent emission of Silene otites (Caryophyllaceae), a species regarded as being nocturnal and pollinated by moths and mosquitoes. We found, however, that S. otites is not only visited at night by moths and mosquitoes, but also by a wide range of day‐active insects. Furthermore, both the intensity and composition of floral scent change during the course of the day. Total scent emission reached its maximum in the early hours of the night when compounds known to be attractants for moths and/or mosquitoes, such as lilac aldehyde, benzaldehyde, phenylacetaldehyde and 2‐phenylethanol, dominated the scent. However, although less intensive, emission continued during the day. In the early morning, α‐pinene, hotrienol, 2‐phenylethanol and δ‐3‐carene were the dominant scent compounds. (E)‐β‐Ocimene, hotrienol and benzyl alcohol contributed proportions of at least 10% before midday when flies, such as syrphids, were abundant flower visitors, whereas linalool and hotrienol contributed to the scent with at least 10% each in the afternoon when bees also contributed to flower visits. We conclude that, in S. otites, the changing emission patterns are ‘in tune’ with the olfactory abilities, preferences and activity times of its day‐ and night‐active potentially pollinating flower visitors. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 447–460.     

Addition of terpenoids to pear ester plus acetic acid increases catches of codling moth (Lepidoptera: Tortricidae)

Field studies were conducted to evaluate new kairomone blends in combination with pear ester (E,Z)‐2,4‐ethyl decadienoate (PE) and acetic acid (AA) for their attraction of male and female codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkhausen. The addition of decanal to either AA or PE alone significantly increased total and female moth catches. However, the addition of decanal did not improve the attraction of PE + AA. The addition of either the pyranoid (PyrLOX) or furanoid (FurLOX) linalool oxide but not linalool (LOL) increased moth catches with PE but did not increase catches with PE + AA. Similarly, the addition of PyrLOX plus decanal did not improve PE + AA. The addition of (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) to either AA, PE + AA or PE + AA+decanal did not significantly increase moth catches. However, the addition of PyrLOX to traps with PE + AA and DMNT (4‐component lure) significantly increased moth catches compared with PE + AA alone or any of the ternary blends of these volatiles. Females accounted for 60%–80% of the total catch with this 4‐component lure. The 4‐component blend with PyrLOX was a more attractive lure than similar blends that substituted LOL, or a binary blend of LOL and FurLOX for PyrLOX. The 4‐component blend caught nearly fourfold more total and female moths than the purported attractant N‐butyl sulphide when it was used in combination with PE + AA. These results indicate that significant improvements in monitoring, mating disruption and mass trapping of codling moth are possible. Further studies are needed to assess the new attractive blend's effectiveness in combination with sex pheromone lures and to evaluate whether other host plant volatiles can be added or substitute for DMNT or LOX when used in combination with PE + AA.