Influence of monoterpene vapors on spruce spider mite,Oligonychus ununguis,adult females

Adult female spruce spider mite,Oligonychus ununguis (Jacobi), were exposed to various concentrations of four host conifer monoterpene vapors (limonene,-pinene,-pinene, and ³-carene) for 24 hr to determine the lethal and sublethal effects. All four compounds were toxic to the mites. Further, at concentrations below the calculated LC₅₀s, all four compounds decreased oviposition by the mites and three of the compounds (limonene,-pinene, and-pinene) influenced movement. WhereasO. ununguis populations may not normally be exposed to high concentrations of host monoterpenes, trees continuously emit some monoterpene vapors, and when trees are damaged or under stress, oleoresin may accumulate at points on the external surface of tree tissues thereby exposing mites to the influence of monoterpene vapors.     

Evaluation of some weed extracts against field dodder on alfalfa (Medicago sativa)

Experiments were conducted to evaluate the effectiveness of some weed extracts against field dodderCuscuta campestris Yunck. on alfalfa (Medicago stiva L.) and to identify and quantify the phytotoxic agents of these extracts. All concentrations of aqueous extract of every weed showed significant effectiveness on dodder when compared to the untreated plant under lath house and field conditions. Control percentages of the (0.5 g) of Bermuda grass (Cynodon dactylon) and wall goosefoot (Chenopodium murale) ranged between 83 and 96, and the same concentration caused injury to alfalfa foliage up to 43% when applied in the field. Phytotoxic agents were identified as phenolic compounds such as chlorogenic, isochlorogenic,p-coumaric acids, and scopoletin. Their quantities varied with species; Bermuda grass had the highest content (32.2 g/g dry weight) followed by Johnson grass (Sorghum halepense), well goosefoot, and tumble pigweed (Amaranthus albus). These results might aid in screening for effective alternate approaches for controlling dodder on alfalfa planted for seeds.     

Fate of quinolizidine alkaloids through three trophic levels:Laburnum anagyroides (Leguminosae) and associated organisms

The quinolizidine alkaloids (QA) of golden rain,Laburnum anagyroides, and those of phytophagous insects associated with the plant, as well as of parasitoids of the latter, were analyzed by capillary GLC and GLC-MS. The alkaloid content in samples of vegetative plant parts was high at the beginning of the season, then decreased, while that of reproductive organs was high throughout flowering, pod formation, and maturation. The analyses showed that the QA of the plant passed through two higher trophic levels (herbivorous insects and their parasitoids) and that the alkaloid pattern changed little during the passage. The alkaloids were present in two phytophagous insect species associated with golden rain: the predispersal seed predator,Bruchidius villosus [5–13g/g fresh weight (fw)], andAphis cytisorum (182–1012g/g fw), an aphid that feeds on shoots, leaves, and inflorescences. Braconid and chalcidoid parasitoids emerging from the bruchid host also contained alkaloids (1.3–3g/g fw), as did three foraging ant species,Lasius niger, Formica rufibarbis, andF. cunicularia (45g/g fw), that visited the aphid colonies or honeydew-covered leaves of aphid-infested plants. The hypothesis that developing bruchid larvae and/or the plant manipulate QA supply to infested seeds was not supported, because QA content of leftover endosperm in seeds after bruchid development was similar to that of uninfested seeds. The frass of developing bruchid larvae was rich in QA (31g/ g dry weight). While aphids sequestered, the bruchid larvae took up and eliminated QA with the frass without chemical transformation.     

Sex Pheromone Components of Casuarina Moth, Lymantria xylina

cis-7,8-Epoxy-2-methyleicosane is a sex pheromone component of the Casuarina moth, Lymantria xylina Swinhoe. The compound was extracted from pheromone glands of female moths and was identified by coupled gas chromatographic–electroantennographic detection (GC-EAD) and GC–mass spectrometry. In field experiments in Taiwan, traps baited with either or both of (7R,8S)-cis-7,8-epoxy-2-methyleicosane (>99% ee) [termed here (+)-xylinalure] and (7S,8R)-cis-7,8-epoxy-2-methyleicosane (>99% ee) [termed here (–)-xylinalure] captured male L. xylina. Addition of further candidate pheromone components to xylinalure did not enhance its attractiveness. Demonstration of whether or not female L. xylina produce both optical isomers of xylinalure, and determination of the ratio, will require pheromone extract analyses on a chiral, enantiomer-separating column (as yet unavailable) or derivatization of epoxides in accumulated gland extracts. Attraction of male L. xylina to either enantiomer of xylinalure contrasts with enantiospecific production of, and/or response to, epoxy pheromones in congeners. With no other nocturnal lymantriid moth known in Taiwan to utilize xylinalure for pheromonal communication, enantiospecific fine tuning of xylinalure, or evolution of a more complex pheromone blend, may not have been necessary for L. xylina to maintain specificity of sexual communication. Racemic xylinalure will be appropriate for pheromone-based detection surveys of L. xylina in North America.     

(3Z,6Z,9Z)-Nonadecatriene and enantiomers of (3Z,9Z)-cis-6,7-Epoxy-nonadecadiene as sex attractants for two geometrid and one noctuid moth species

Sex attractants for the geometrid mothsEufidonia convergaria andCaripeta angustiorata, and the noctuid mothRivula propinqualis have been elucidated during field screening of a series of (3Z,6Z,9Z)-triene hydrocarbons (C_17–22), and the racemic and enantiomerically enriched monoepoxydienes derived from those hydrocarbons. Biologically active compounds were identified by a combination of field testing of synthetic standards, electroantennography, and coupled gas chromatography-electroantennogram detection.E. convergaria males were optimally attracted by a 11 blend of (3Z,9Z)-(6S,7R)-epoxy-nonadecadiene (3Z,9Z-6S,7R-epoxy-19H); other abbreviations follow the same system) with (3Z,6Z,9Z)-nonadecatriene (3Z,6Z,9Z-19H). The 6R,7S enantiomer of the epoxide had no apparent biological activity, either as an attractant or as a behavioral antagonist. Male moths also were attracted to blends of the C₁₈ and C₂₀ homologs of the triene and the epoxide. 3Z,6Z,9Z-19H and 3Z,6Z-cis-6,7-epoxy-19H were identified inE. convergaria female pheromone gland extracts. Males of the geometrid moth speciesC. angustiorata were attracted by a 11 blend of 3Z,6Z,9Z-19H and enantiomerically enriched 3Z,9Z-6R,7S-epoxy-19H. Males of the noctuid mothR. propinqualis were attracted by an approximately 101 blend of 3Z,6Z,9Z-19H and enantiomerically enriched 3Z,9Z-6S, 7R-epoxy-19H. The components were synergistic, with neither being attractive alone. The blend ratio was quite specific, as the attractiveness of blends decreased sharply on either side of the optimum ratio.Issued as NRC No. 30266.     

Effects of α-Terthienyl on the midgut detoxification enzymes of the European corn borer,Ostrinia nubilalis

The biochemical basis for the tolerance of the European corn borer,Ostrinia nubilalis, to the phototoxin-terthienyl was investigated by measuring the midgut polysubstrate monooxygenases and glutathioneS-transferase activities.-Terthienyl administered in the diet to the corn borers increased the level of cytochromeb ₅, NADH-cytochromec reductase,O-demethylase, and glutathioneS-transferase activities. The induced detoxification enzyme activities should enable the corn borer to metabolize-terthienyl more efficiently and therefore render the corn borer highly tolerant to-terthienyl.     

Mandibular gland secretions of the male beewolvesPhilanthus crabroniformis,P. barbatus,andP. pulcher (Hymenoptera: Sphecidae)

The composition of the territorial marking pheromones from mandibular glands of males of the beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher have been determined. The structures of the components were elucidated by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. The major compound ofP. crabroniformis is isopropyl tetradecanoate, with somewhat lesser amounts of 2-tridecanone, 3-methyl-3-butenyl tetradecanoate, and 928 (Z)(E)-11-eicosen-1-ol. The major compounds ofP. barbatus are ethyl tetradecanoate and hexadecanal, which are present in approximately a 6040 ratio. These two compounds comprise over 95% of the neutral lipids. Also present in lesser amounts are ethyl dodecanoate, tetradecanal, hexadecan-1-ol, a ^x -octadecen-1-ol, and octadecan-1-ol. The major compounds ofP. pulcher are ethyl (Z)-7-hexadecenoate and geranylgeraniol acetate, which comprise nearly 90% of the neutral lipid fraction, with smaller amounts of tetradecanal, pentadecanal, and ethyl hexadecanoate; trace amounts of ^x hexadecenal, hexadecanal, and octadecanal are also present.     

Chemical composition of degrading mangrove leaf litter and changes produced after consumption by mangrove crabNeosarmatium smithi (Crustacea: Decapoda: Sesarmidae)

The leaves of the mangroveCeriops tagal contained 3.2–4.1% (all percentages relate to dry weight) ofd-1-O-methyl-muco-inositol previously unreported in mangroves. They consisted of 37% aqueous acetone-water-soluble material, 18% water-insoluble polysaccharides, and ca. 50% polyphenols, which include soluble and insoluble tannins and lignin. The polysaccharide component sugars were glucose, arabinose, uronic acids, mannose, xylose, galactose, and rhamnose in the proportions 28262210752, respectively. The leaves were pectate rich, and the low level of glucan was presumed to consist mainly of cellulose. After four weeks of biodegradation, ca. 60% of the acetone-water-soluble material was lost from the leaves. Degradation processes greatly altered the polysaccharide components in the leaves. Pectates were rapidly degraded, while other polysaccharides, although reduced proportionately, resisted degradation at about the same level, and all component sugars were found in the 8-week-old leaves. Apparent lignin contents increased from 15 to >30% during biodegradation up to eight weeks. The yields of the major fractions in corresponding fecal material fromNeosarmatium smithi showed a similar trend to the diets. An enrichment of the insoluble residue was noticeable due to the digestion of dialyzable material. The fecal carbohydrate content was greatly reduced (7–11%) and the apparent lignin increased (27–39%) due to its resistance to degradation. All dietary polysaccharide component sugars were found in the fecal residues, including some uronic acids. The leaves also contained a readily water-soluble fraction (15%) which consisted of pectates strongly complexed with proanthocyanidins.     

Impact of 10 Dietary Sterols on Growth and Reproduction of Daphnia galeata

In crustaceans, cholesterol is anEssential nutrient, which they must directly obtain from their food or by bioconversion from other dietary sterols. Eukaryotic phytoplankton contain a great variety of sterols that differ from cholesterol in having additional substituents or different positions and/or number of double bonds in the side chain or in the sterol nucleus. In this study, we investigated to what extent these structural features affect the growth and reproduction of Daphnia galeata in standardized growth experiments with the cyanobacterium Synechococcus elongatus supplemented with single sterols as food source. The results indicated that ⁵ (sitosterol, stigmasterol,Desmosterol) and ^5,7 (7-dehydrocholesterol, ergosterol) sterols meet the nutritional requirements of the daphnids, while the ⁷ sterol lathosterol supports somatic growth and reproduction to a significantly lower extent than cholesterol. Dihydrocholesterol (⁰) and lanosterol (⁸) did not improve the growth of D. galeata, and growth was adversely affected by the ⁴ sterol allocholesterol. Sterols seem to differ in their allocation to somatic growth and reproduction. Thus, structural differences of dietary sterols have pronounced effects on life-history traits of D. galeata.     

Sex pheromone ofGrapholita funebrana occurrence ofZ-8- andZ-10-Tetradecenyl acetate as secondary components

Z-8-Dodecenyl acetate (Z8–12Ac),E-8-dodecenyl acetate (E8–12Ac),Z-8-tetradecenyl acetate (Z8–14Ac),Z-10-tetradecenyl acetate (Z10–14Ac), andZ-8-dodecen-1-ol (Z8–12OH) were identified in the proportions 10013052 in female sex gland extracts ofGrapholita funebrana, accompanied by saturated acetates from 12 to 20 carbons with tetradecyl acetate predominating.Z10–14Ac has not previously been described as a lepidopteran sex pheromone component. Best attraction of males is obtained withZ8–12Ac in the presence of a higher proportion ofE8–12Ac than in the female. Inclusion of the 14-carbon acetates did not augmentG. funebrana catches but inhibitedG. molesta. On the other hand, addition ofZ8–12OH at the level optimal forG. molesta reduced attraction ofG. funebrana.     

A study of factors that control biosynthesis of the compounds which comprise the boll weevil pheromone

Biosynthesis of the four monoterpene compounds that comprise the pheromone of the male boll weevil,Anthonomus grandis Boheman, [1, (+)-cis-2-isopropenyl-1-methylcyclobutaneethanol; II, (Z)-3,3-dimethyl-^1,-cyclohexaneethanol; III, (Z)-3,3-dimethyl-^1,-cyclohexaneacetaldehyde; and IV, (E)-3,3-dimethyl-^1,-cyclohexane-acetaldehyde] was studied. More pheromone was biosynthesized in the summer months, somewhat less was produced by males in the presence of females than by isolated males, and the pheromone was concentrated in the gut and surrounding tissue of the abdomen of the males. Incubation of abdomens with the pheromone alcohols yielded related hydrocarbons, aldehydes, and alcohols, which suggested the presence of several enzyme systems. Boll weevils were able to allylically oxidize myrcene and limonene to alcohols, a capability that suggests pheromone precursors may be at least in part inhaled rather than ingested. The hemolymph may then transport the precursor to the gut or some alternative site where allylic oxidation to the pheromone occurs.Coleoptera: Curculionidae.In cooperation with the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Mississippi 39762. Received for publication.     

Syntheses and properties of polyimides based on bis(p-aminophenoxy)biphenyls

Three biphenyl unit-containing diamines,4,4-bis(p-aminophenoxy)biphenyl (III_a), 2,2-bis(p-aminophenoxy)biphenyl (III_b), and 3,3,5,5-tetramethyl-4,4-bis(p-aminophenoxy)biphenyl (III_c), were prepared by the chlorodisplacement ofp-chloronitrobenzene with 4,4-biphenol (I_a), 2,2-biphenol (I_b), and 3,3,5,5-tetramethyl-4,4-biphenol (I_c), respectively, giving the corresponding bis(nitrophenoxy) compounds II_a-c, followed by catalytic reduction with palladium (Pd) and hydrazine. Three series of polyimidesp-PI,o-PI, and Me-PI were prepared from diamines III_a-c and aromatic tetracarboxylic dianhydrides via a two-stage procedure that included ring-opening polyaddition to give poly(amic acid)s followed by thermal cyclodehydration to polyimides. The resultant three series of poly(amic acid)s had inherent viscosities of 1.09–2.83, 0.78–1.93, and 1.55–3.09 dL/g, respectively. Almost all the poly(amic acid)s could be solution-cast and thermally converted into transparent, flexible, and tough polyimide films. All the polyimides were characterized by solubility, tensile test, wide-angle X-ray scattering measurements, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Effects of the structures of aromatic diamines and dianhydrides on the properties of polyimides were investigated.     

What defense doesSchouwia purpurea (Cruciferae) have against the desert locust?

A field study of the food eaten by solitary desert locusts was carried out in a winter breeding area in Mauritania. The food eaten, determined by the plant epidermis found in fecal pellets, was compared to the plant's availability in the habitat.Schouwia purpurea, well represented in the diets, was dominant at the study site. Adults had a preference forTribulus terrester. Growth and feeding on these two plants were compared. The high water content ofS. purpurea leaves limited the dry matter eaten and slowed down growth. Glucosinolates were separated and quantified by gas chromatography. There are 132mol/g dry matter in green leaves. In multiple choice tests, with paper disks, glucosinolate extracts were phagostimulant at a low concentration (21mol/g dry matter) and repulsive at a higher one (214mol/ g dry matter). Biting behavior onS. purpurea was recorded and analyzed on video. The importance ofSchouwia purpurea in desert locust habitats and its defenses is discussed.     

Sex pheromone chemistry of the western spruce budwormChoristoneura occidentalis Free

SCOT capillary Chromatographic and SCOT capillary chromatographic-mass spectrometic analyses of gland washes and effluvia of virgin femaleChoristoneura occidentalis Free, have been conducted with both a diapausing and nondiapausing strain of this insect. The following compounds were identified in gland washes and effluvia in both strains:E andZ11–14Ald,E andZ11–14Ac,E andZ11–14OH and 14Ald, 14Ac, and 14OH. The average aldehyde: acetate: alcohol ratio found by analysis of single glands by virgin females (nondiapausing strain) was 170.73. Analysis of virgin female effluvia gave this ratio as 1038 (diapausing strain: %Z=8, 11, 15, respectively) and 1036 (nondiapausing strain: %Z=8, 11, 12, respectively). The saturated components were generally 1–2% of theE isomer in each case. Comparisons of EAG responses of bothC. occidentalis andC. fumiferana toE11–14Ald,E11–14Ac andE11–14OH were made. Correlations with both laboratory and field data previously published were also made betweenC. fumiferana andC. occidentalis.Lepidoptera: Tortricidae.     

Leaf surface chemicals fromNicotiana affecting germination ofPeronospora tabacina (adam) sporangia

A bioassay was used to evaluate the effects of cuticular leaf components, isolated fromN. tabacum, N. glutinosa (accessions 24 and 24a), and 23other Nicotiana species, on germinationof P. tabacina (blue mold). The leaf surface compounds included- and-4,8,13,-duvatriene-l,3-diols (DVT-diols), (13-E)-labda-13-ene-8-,15-diol (labdenediol), (12-Z)-labda-12,14-diene-8-ol (cis-abienol), (13-R)-labda-8,14-diene-13-ol (manool), 2-hydroxymanool, a mixture of (13-R)-labda-14-ene-8,13-diol (sclareol), and (13-S)-labda-14-ene-8,13-diol (episclareol), and various glucose and/or sucrose ester isolates. The above in acetone were applied onto leaf disks of the blue moldsusceptibleN. tabacum cv. TI 1406, which was then inoculated with blue mold sporangia. Estimated IC₅₀ values (inhibitory concentration) were 3.0g/cm² for-DVT-diol, 2.9/cm² for-DVT-diol, 0.4g/cm² for labdenediol and 4.7g/cm² for the sclareol mixture. Manool, 2-hydroxymanool, andcis-abienol at application rates up to 30g/cm² had little or no effect on sporangium germination. Glucose and/or sucrose ester isolates from the cuticular leaf extracts of 23Nicotiana species and three different fractions fromN. bigelovii were also evaluated for antimicrobial activity at a concentration of 30g/cm². Germination was inhibited by >20% when exposed to sugar esters isolated fromN. acuminata, N. benthamiana, N. attenuata, N. clevelandii, andN. miersii, and accessions 10 and 12 ofN. bigelovii. These results imply that a number of compounds may influence resistance to blue mold in tobacco.     

Role of the isoflavonoid coumestrol in the constitutive antixenosic properties of “Davis” soybeans against an oligophagous insect,the mexican bean beetle

The antixenosic properties of the isoflavonoid, coumestrol, were tested in dual-choice leaf disk bioassays with the Mexican bean beetle (Epilachna varivestis Mulsant).E. varivestis preferred the methanol-r,reated (solvent-control) disk when the coumestrol concentration was 1.8 or 0.9/leaf disk. No preference was observed between the coumestrol-treated and the solvent-control disks when the coumestrol concentration was higher, at 3.6, or lower, at 0.45g/leaf disk. Coumestrol alone clearly is not responsible for the significant constitutive antixenosic properties of Davis soybeans,Glycine max (L.) Merrill, because the amount of coumestrol in these plants is significantly less than the minimum concentration which was antixenosic in this study. However, it might contribute to a constitutive antixenosis in Davis involving a profile of allelochemicals. A computer-aided densitometer, adapted to measure the leaf disk area, increased the resolution of the leaf area 250 (X)-fold as compared to the standard LI-COR leaf area meter.     

Isolation of substance from sweet potato (Ipomoea batatas) periderm tissue that inhibits seed germination

Chromatographic procedures were used to isolate inhibitors of seed germination from sweet potato root periderm tissue. The inhibitory activity of all fractions was monitored using a proso millet seed germination bioassay. A single HPLC peak, representing approximately 1.2% of the periderm dry weight, accounted for most of the inhibitory activity. The active fraction was labile in methanolic solution. Further fractionation of this peak by HPLC methods was not successful. In vitro seed germination dose-response relationships were established for the peak. The various seed species exhibited an extremely wide range of sensitivity. The I₅₀ values were 0.16, 0.013 and 0.011 mg/ml for redroot pigweed, velvetleaf, and proso millet, respectively. Tall morning glory was not inhibited by any concentration tested.     

Comparative analysis of sex-pheromone-response antagonists in three races of European corn borer

Behavioral responses of males from three New York races of European corn borer,Ostrinia nubilalis (Hübner), to various suspected sexpheromone-response antagonists were investigated with a flight tunnel protocol. Males from a bivoltine (Z) race and from a univoltine (Z) race utilizing a natural pheromone blend of 982 (Z)-(E)-11-tetradecenyl acetates and males from a bivoltine (E) race utilizing a 199 (Z)-(E)-11-tetradecenyl acetate ratio were flown to their natural blends and to blends containing 1 % of one of the following additional compounds: Z9–12OAc,E9–12OAc,Z9–14OAc, andE9–14OAc. In each race, the added components lowered significantly the number of individuals completing the behavioral sequence. The only exception was bivoltineE males flown to a blend withE9–12OAc added. The number completing the sequence in this case was statistically not significantly lower than the number that completed the sequence to the standard blend. In all three races, theZ9–14OAc produced the most dramatic reduction in completed flights, and in the univoltineZ race, this added component was significantly more effective in reducing completed flights than any other added component. The response to the Z9–14OAc is understandable given recently published findings of an electrophysiological study of single sensilla in the European corn borer.     

Ethanol and Ambrosia Beetles in Douglas Fir Logs Exposed or Protected from Rain

Logs from the base of Douglas fir (Pseudotsuga menziesii) trees cut in October 1993 were randomly assigned to one of three treatment groups: (1) wet logs—cut from the fallen tree and left exposed to rain, (2) dry logs—cut from the fallen tree, placed on blocks, and protected from rain under a plastic tent, and (3) crown logs—left attached to the fallen tree with its branches intact and exposed to rain. The following May, ethanol concentrations were highest in the phloem and sapwood of wet logs (0.24 and 0.35 mol/g fresh wt, respectively). Ethanol concentrations in tissues from dry and crown logs were similar to each other (ranging from 0.002 to 0.03 mol/g fresh wt), but were significantly lower than in wet logs. It appears that rain absorbed by the outer bark of wet logs creates a barrier to gas exchange between living tissues and the atmosphere, which facilitates the development of hypoxic conditions necessary for ethanol synthesis and accumulation. Branches on crown logs exposed to rain help maintain low ethanol concentrations in the log tissues; we discuss several potential mechanisms to explain this response. By early September, the densities of Gnathothrichus spp. gallery entrance holes were high on wet logs (21.5/m²) and low on dry (2.5/m²) and crown logs (5.8/m²), indicating their preference for logs with higher ethanol concentrations. Protecting logs from rain will significantly reduce ethanol concentrations and the density of ambrosia beetle galleries. Leaving branches attached to logs will produce similar results, but its effectiveness may vary depending on the environmental conditions. Host selection by secondary scolytid beetles that use ethanol as a kairomone can be manipulated and possibly managed by controlling the production of ethanol in the host resource.     

New lepidopteran sex attractants found by systematic field screening of blends containing (Z)-11- and (E)-11-tetradecenal

By screening (Z)-11-tetradecenal and (E)-11-tetradecenal alone, mixed with each other or mixed with corresponding alcohols or acetates, sex attractants were discovered or improved for nine Lepidoptera. Attractants were found forAcleris sparsana, A. tripunctana, Aphelia viburnana (all Tortricidae),Cilix glaucata (Drepanidae), andCosmia trapezina (Noctuidae). The significance of 11-tetradecenals in tortricid sex attractants is discussed.