Influence of tobacco leaf surface chemicals on germination ofPeronospora tabacina adam sporangia

Chromatographic procedures were utilized to isolate and purify components of tobacco cuticular extracts and leaf surface chemicals.In vitro microbial bioassays determined the influence of these leaf surface compounds on germination and germ tube morphology ofP. tabacina sporangia, the tobacco blue mold pathogen, and to a lesser extentAlternaria alternata, the tobacco brown spot pathogen. Exposure to 10 g/cm² of - and -duvatrienemonols, sucrose esters, or hydrocarbons did not inhibit germination, whereas germination was significantly decreased bycis-abienol.cis-Abienol did not inhibit sporangial germination when combined with sucrose esters or hydrocarbons at a combined 10 g/cm². Germination of sporangia was completely inhibited by - and -duvatrienediols. In contrast to a previous report, -DVT-diol was more inhibitory than the isomer. Toxic effects of the DVT-diols were not altered by pH. Diluting the DVT-diols to less than 0.1 g/cm² resulted in a small but significant stimulation of germination. Previously, the DVT-diols had been identified only as inhibitory toP. tabacina. None of the leaf surface chemicals affected germination ofA. alternata conidia.Present Address: Department of Forestry, Biltmore Hall, North Carolina State University, P.O. Box 8002, Raleigh, North Carolina 27695-8002.     

Modification of allelopathic effects ofp-coumaric acid on morning-glory seedling biomass by glucose,methionine, and nitrate

Studies of allelopathy have emphasized primarily the identification and quantification of phytotoxins in soils, with only limited attention directed toward how organic (carbon) and inorganic constituents (nutrients) in the soil may modify the action of such phytotoxins. In the present study, increasing carbon (C) levels (up to 108g C/g soil) supplied as glucose, phenylalanine, orp-hydroxybenzoic acid did not alter morning-glory biomass, but similar C levels supplied as leucine, methionine, orp-coumaric acid were inversely related to morning-glory biomass. Similar joint action and multiplicative analyses were used to describe morning-glory biomass response to various C sources and to generate dose isolines for combinations ofp-coumaric acid and methionine at two NO₃-N levels and for combinations ofp-coumaric acid and glucose at one NO₃-N level. Methionine, glucose, and NO₃-N treatments influenced the inhibitory action ofp-coumaric acid on biomass production of morning-glory seedlings. For example, results from the multiplicative analysis indicated that a 10% inhibition of morning-glory biomass required 7.5gp-coumaric acid/g soil, while the presence of 3.68g methionine/g soil thep-coumaric acid concentration required for 10% inhibition was only 3.75g/ g soil. Similar response trends were obtained forp-coumaric acid and glucose. The higher NO₃-N (14 vs. 3.5g/g) treatments lowered the methionine and increased thep-coumaric acid concentrations required for 10% inhibition of morning-glory biomass. These results suggested that allelopathic interactions in soil environments can be a function of interacting neutral substances (e.g., glucose), promoters (e.g., NO₃-N), and/or inhibitors (e.g., methionine andp-coumaric acid) of plant growth.The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of products named, nor criticism of similar ones not mentioned.     

Effect of fungal metabolite peramine and analogs on feeding and development of argentine stem weevil (Listronotus bonariensis)

Peramine, a pyrrolopyrazine alkaloid produced by the fungal endophyte of perennial ryegrassAcremonium lolii, deterred the feeding of both adults and larvae of the graminacious herbivore, the Argentine stem weevil (Listronotus bonariensis), at 0.1 g/g and 10 g/g, respectively. In a no-choice test fewer stem weevil larvae fed and developed on diet containing as little as 2 g/g peramine. The proportion of larvae which did not develop beyond the first instar was higher on diet containing peramine and appeared to be due to a higher proportion of larvae which did not feed. For larvae which fed on the peramine-containing diet, feeding scores and times to pupation were not significantly different from those of controls. A number of simple peramine analogues showed feeding-deterrent activity against adult weevils, indicating the importance of the pyrrolopyrazine ring system of peramine in determining feeding-deterrent activity.     

Cardenolide content and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus L., and their larval host-plant milkweed,Asclepias asperula subsp.Capricornu (woods.) woods., in north central Texas

This paper is the second in a series on cardenolide fingerprinting of monarch butterflies and their host-plant milkweeds in the eastern United States. Spectrophotometric determinations of the gross cardenolide content ofAsclepias asperula plants in north central Texas indicated wide variation ranging from 341 to 1616 g/0.1 g dry weight. The mean plant cardenolide concentration (886 g/0.1 g) is the highest for any milkweed species on which monarch cardenolide profiles have been produced. Forty-one butterflies reared individually on these plants contained a skewed distribution of cardenolide concentrations ranging from 231 to 515 g/0. 1 g dry weight with a mean of 363g/0.1 g. The uptake of cardenolide by the butterflies was independent of plant concentration, suggesting that saturation occurs in cardenolide sequestration by monarchs when feeding on cardenolide-rich host-plants. Female monarchs contained significantly greater mean cardenolide concentrations (339 g/0.1 g) than did males (320 g/0.1 g). The mean dry weight of the male butterflies (0.211 g) was significantly greater than the female mean (0.191) so that the mean total cardenolide contents of males (675 fig) and females (754 g) were not significantly different. Butterfly size was not significantly correlated to butterfly cardenolide concentration when differences due to sex and individual host-plant concentration were removed. Thin-layer chrornatograms of 24 individual plant-butterfly pairs developed in two solvent systems resolved 22 individual spots in the plants and 15 in the butterflies.A. asperula plants appear to contain several relatively nonpolar cardenolides of the calotropagenin series which are metabolized to more polar derivatives in the butterflies. Quantitative evaluation of theR _f values, spot intensities, and probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint clearly distinct from those previously established for monarchs reared on otherAsclepias species. Our data support the use of fingerprints to make ecological predictions concerning larval host-plant utilization.A. asperula subsp.capricornu andA. viridis Walt, are the predominant early spring milkweeds throughout most of the south central United States. Cardenolide-rich monarchs reared on these two species may be instrumental in establishing and reinforcing visual avoidance of adults by naive predators throughout their spring and summer breeding cycle in eastern North America.Lepidoptera: Danaidae.Apocynales: Asclepiadaceae.     

Responses of male codling moths (Laspeyresia pomonella) to codlemone and other alcohols in a wind tunnel

The primary pheromone (E,E)-8,10-dodecadien-1-ol (I, codle-mone), 11 further alcohols, and binary blends of both were evaluated for attractiveness as defined by the percentage ofL. pomonella males showing oriented upwind flight terminated by landing at the source within 10 min after release. Sources of I were attractive from 10^–5 g to 10¹ g, with approx. 70% males responding at 10^–3–10^–1 g. Most other alcohols also showed attractiveness, but the dose-response curves differed greatly with respect to the range of effective lure doses as well as the maximum response level reached at any dose. (E,E)-7,9-Undecadien-1-ol (III) revealed a dose-response curve similar in shape to I but shifted towards higher concentrations. (E,E)-8,10-Tridecadien-1-ol (II) and (E)-8,10-undecadien-1-ol (IV) exhibited threshold values of 10^–5 g (same as for I) and were effective over, respectively, seven and nine decades of source load, but they did not reach a response level of 40% at any test amount. (E)-9,11-Dodecadien-1-ol (VI) and the monoenes (E)-8-, (E)-10-, and (Z)-10-dodecen-1-ol (VIII-X) showed weak attractivity restricted to one to three test doses. Upwind approaches that broke off a few centimeters from the source were rarely seen in tests with I but frequently occurred with some of the analogs. When combined with 10^–3 g of I, all alcohol analogs showed inhibitory properties, although the amounts required to obtain a significant lowering of response differed by up to 10⁵-fold. This amount was the lowest (10^–4 g) for the positional isomer VI, and the highest (10¹ g) for undecan-1-ol (XI) and dodecan-1-ol (XII). With some mixtures, the presence of the inhibitor appeared to cause an alteration in landing behavior. No synergistic effects were seen in these tests. The results are briefly considered with respect to the sensory perception of the test stimuli and the involvement of minor components in the female pheromone blend.     

Lesser peachtree borer: Influence of pheromone concentration,isomeric blend,and experimental design on trap capture

Trap capture data from Ohio and Wisconsin show that (E,Z)-3-13-octadecadien-1-ol acetate alone is an effective trap bait for maleSynanthedon pictipes (Grote and Robinson). Attractiveness increased by increasing attractant concentration but not by adding theZ,E geometrical isomer.S. pictipes males partitioned themselves in a linear fashion among traps baited with 10–100 g of attractant in 10-g increments. Furthermore, they discriminated between 50- and 100-g baits placed in the same tree. These and other results indicate that, in clearwing experiments involving noninhibitory compounds and blend tuning, high trap density can be used successfully.Lepidoptera: Sesiidae.Approved for publication as Journal Article No. 45–79 of the Ohio Agricultural Research and Development Center, Wooster, Ohio 44691.Investigations supported in part by USDA, Cooperative State Research Service, Contract No. 316-15-59.     

Effects of soil nitrogen level on ferulic acid inhibition of cucumber leaf expansion

It has been suggested that the allelopathic activity of phenolic acids should be primarily important in soils of low fertility. If this is true, then plant growth inhibition by phenolic acids may be unimportant in managed agricultural soils. The objective of this study was to determine how soil nitrogen (N) level might modify phenolic acid inhibition of growth. Cucumber seedlings (Cucumis sativus cv Early Green Cluster) grown in containers in growth chambers under varying N levels (5, 10, 15, 20, and 25 g N/g soil) in Portsmouth B,-horizon soil material were treated with ferulic acid (0 or 10 g/g soil). Nitrogen and ferulic acid (FA) were applied every other day to the soil surface. The amount of FA in the soil solution declined with depth in the containers. A more rapid disappearance of FA from the soil solution was observed for the last FA treatment (0% recovered after 10 hr on day 23) than the first treatment (44% recovered after 10 hr on day 13). Both low N (5 g N/g soil) and FA treatments reduced shoot dry weight, the mean absolute (AGR) and the mean relative (RGR) rates of leaf expansion, and increased the root-shoot ratio. High N treatments reduced shoot dry weight and the AGR. Ferulic acid inhibited cucumber seedling growth over a range of N concentrations, suggesting that the allelopathic activity of phenolic acids may be important in both nutrient limiting and nonlimiting soils for some species.Paper No. 12219 of the journal series of the North Carolina Agricultural Research Service, Raleigh, North Carolina 27695-7601. The use of tradenames in this publication does not imply endorsement by the North Carolina Agricultural Research Service of products named, nor criticism of similar ones not mentioned.     

Attraction of 3-Methyl-1-Butanol and Ammonia Identified from Enterobacter agglomerans to Anastrepha suspensa

Tests demonstrated that volatile chemicals emitted from Enterobacter agglomerans, a bacterium that has been isolated from adults as well as fruit infested with larvae of the Caribbean fruit fly, Anastrepha suspensa (Loew) and other pest fruit flies, are attractive to female A. suspensa in laboratory bioassays. 3-Methyl-1-butanol and ammonia were identified as the two primary volatile chemicals released from active cultures of E. agglomerans. No 3-methyl-1-butanol and little ammonia (16.0 g/hr) are released from sterile tryptic soy agar plates. E. agglomerans-inoculated tryptic soy agar plates, however, released an average of 1.5 ± 0.53 g/hr 3-methyl-1-butanol and 332.9 ± 239.16 g/hr ammonia after 24 hr of growth. 3-Methyl-1-butanol lures were formulated in a membrane-based system to provide a constant release rate of synthetic chemical. Release rates ranged from 0.046 ± 0.007 to 12.16 ± 2.76 g/hr. In laboratory tests, equal numbers of females were captured in response to ammonium carbonate lures that released ammonia at the rate of 100 g/hr and to 3-methyl-1-butanol lures that released 12.16 ± 2.756 g/hr of synthetic material. The combination of the two lures was more attractive than ammonia alone. Availability of lures formulated for a range of 3-methyl-1-butanol release rates will facilitate field tests of this putative microbial attractant and may lead to a better understanding of the role of bacteria in the ecology of pest fruit flies.     

Selection of pheromone trap and attractant dispenser load to monitor black army cutworm,Actebia fennica

Catch rates of black army cutworm moths,Actebia fennica (Lepidoptera: Noctuidae), were determined for different types of traps and different dispenser loads of sex attractant. Of the five traps tested, highest catch (35 males/per night) was obtained with Uni-Traps, whereas Pherocon 1CP, Delta and Hara traps rapidly became saturated at 9, 6, and 11 males/per night, respectively. Multi-Pher traps, like the Uni-Traps, have a covered vertical cone with a large collecting bucket but only catch about 1/3 of the number of moths (9 males/per night) as the Uni-Traps, thus reducing potential saturation. Red rubber septa loaded with 500 g of attractant blend gave a consistent catch for at least 60 days; 1000 and 2000 g loadings lasted for a minimum of 90 days. Polyvinylchloride and red rubber septa dispensers containing 100 g of attractant had similar catch rates, which decreased rapidly with age. Based on these trap and lure-loading experiments, Multi-Pher traps baited with 1000 g of attractant in a red rubber septum were selected for future calibration studies between catch density and population fluctuations on susceptible sites. Two years of monitoring results also are reported.     

Looplure efficacy and electrophysiological responses in three plusiinae species

Source concentration differences of (Z)-7-dodecen-1-ol acetate, or looplure, were evaluated for field trapping efficiency and electrophysiological responses with malePseudoplusia includens (Walker),Trichoplusia ni (Hubner) andRachiplusia ou (Guenné) (Lepidoptera: Noctuidae). Sticky traps baited with 1000 g of the lure captured a significantly greater (P < 0.05) number of maleP. includens andT. ni than any other concentration;R. ou males were caught at a greater rate in traps baited with 100 g of looplure, significantly more (P < 0.05) than with 1000 g. Electroantennogram (EAG) studies demonstrated that antennae of maleP. includens have a lower response threshold to looplure than eitherT. ni orR. ou antennae, the latter demonstrating the highest significant threshold of response. No differences in the stimulus-response functions of the three species were detected.Lepidoptera: Noctuidae.     

Synergism of Polygodial and trans-Cinnamic Acid on Inhibition of Root Elongation in Lettuce Seedling Growth Bioassays

A bicyclic sesquiterpene dialdehyde, polygodial did not inhibit root elongation up to a concentration of 12.5 g/ml in a lettuce seedling assay: trans-Cinnamic acid inhibited the elongation by 50% at 1.2 g/ml (8.1 M). The inhibitory activity of trans-cinnamic acid was enhanced 17-fold when used in combination with 6.25 g/ml (26.5 M) of polygodial. A decrease in the pH of the medium was observed during normal seedling growth, indicating transport of protons from the cells by a plasma membrane H⁺-ATPase. The inhibitory effect of trans-cinnamic acid on the elongation was reduced to some extent in 2 mM phosphate buffer (pH 7.0) during seedling growth. Although polygodial did not inhibit the activity of H⁺-ATPase in the plasma membrane fraction of roots in normally growing seedlings, a decrease in activity was found in the fraction obtained from seedlings incubated with 20 g/ml of polygodial. These results suggest that polygodial functions synergistically with trans-cinnamic acid in the inhibition of root elongation via restriction of proton transport from the cytoplasm of germinated cells.     

Linamarin and histamine in the defense of adultZygaena filipendulae

We determined the protective values of histamine and linamarin to an aposematic moth,Zygaena filipendulae. Using ion-exchange resin techniques, we found that the mean histamine concentrations in the wings were 0.061 ± 0.047 g/mg and 0.013 ± 0.0051 in the moths' bodies (totals: 0.586 g and 2.921 g, respectively, all wet weights). Average HCN evolution (mainly from the bitter cyanogen linamarin) from the wings was 0.049 ± 0.41 g/mg (0.426 g/ml of linamarin could produce this amount of HCN) and 0.029 ± 0.0026 g/mg HCN (0.281 g/mg linamarin) evolved from the bodies (total linamarin 4.09 g and 61.258 g, respectively, all wet weights). Therefore, higher concentrations of toxicants were found in the part of the body most liable to initial attack. We found, in offering various toxic solutions to 10 common quails, that 0.1% linamarin (mean linamarin consumed equal to about 70% of the average total wing content) but 1.0% histamine (mean histamine consumed equal to that found in about 8.9 average wing sets) solutions significantly lowered drinking rates. However, combination solutions were still effectively aversive at 0.001% histamine plus 0.028% linamarin. This synergism would allow a moth under local abiotic or dietary stress to elaborate substantially less of one or both compounds than that normally synthesized. The implications to kin selection are discussed.     

Onion fly trap catch as affected by release rates ofn-dipropyl disulfide from polyethylene enclosures

n-Dipropyl disulfide loadings of at least 1 l and 10 l in polyethylene enclosures were required to effect significant trap catches of onion fly,Hylemya antiqua (Meigen), females and males, respectively. Corresponding release rates for this threshold for trap catch were ca. 100 g/hr. Catches increased with loadings up to 100 l/capsule but then plateaued. As determined gravimetrically, the release rate from enclosures containing a reservoir of chemical remained constant under isothermal conditions but increased exponentially as a function of temperature.Diptera: AnthomyiidaePaper No. 9422 of the Michigan State University Agricultural Experiment Station. Received for publication April 29, 1980.     

Defensive secretions of three species ofAcilius (Coleoptera: Dytiscidae) and their seasonal variations as determined by high-pressure liquid chromatography

A rapid, sensitive, stable, and quantitative high-pressure liquid chromatographic technique was developed for the analysis of defensive secretions obtained from the pygidial and prothoracic glands of dytiscids. Methods were developed for both normal phase (Porasil) and reverse phase (Bondapak C₁₈) columns. The applicability of this technique was demonstrated when defensive compounds ofAcilius semiculcatus, A. sylvanus andA. mediatus were isolated, identified, and quantitated. No major differences were found in the composition of the defensive secretions between the three species. The seasonal defensive titer ofA. semisulcatus was determined from June through October 1977. The pygidial defensive agents (benzoic acid,p-hydroxybenzaldehyde, and methylp-hydroxybenzoate varied from 9.0 to 67.8 g and exhibited a maximum in July, and a steroid from the prothoracic gland varied from 7.1 to 33.2 g and was maximum in October.     

Aphid deterrence by glucose esters in glandular trichome exudate of the wild tomato,Lycopersicon pennellii

Settling of the potato aphid,Macrosiphum euphorbiae, on feeding membranes was deterred by methanolic leaf rinses ofLycopersicon pennellii, or of its F₁ with tomato,L. esculentum. The active compounds in theL. pennellii rinsates were identified as 2,3,4-tri-O-acylglucoses bearing short to medium chain length fatty acids. These compounds are localized in the glandular exudate of the type IV trichomes and may accumulate to levels in excess of 400 g/cm². In choice assays, purified glucose esters fromL. pennellii reduced aphid settling at concentrations as low as 25 g/cm²; at concentrations of 150 g/cm² or more, all aphids avoided treated areas. Glucose esters were also active in deterring aphid settling in no-choice assays. At 100 g/ cm², these esters resulted in increased levels of mortality after 48 hr.     

Induction and/or Selection of Phenolic Acid-Utilizing Bulk-Soil and Rhizosphere Bacteria and Their Influence on Phenolic Acid Phytotoxicity

Bulk-soil and rhizosphere bacteria are thought to exert considerable influence over the types and concentrations of phytotoxins, including phenolic acids, that reach a root surface. Induction and/or selection of phenolic acid-utilizing (PAU) bacteria within the bulk-soil and rhizosphere have been observed when soils are enriched with individual phenolic acids at concentrations 0.25 mol/g soil. However, since field soils frequently contain individual phenolic acids at concentrations well below 0.1 mol/g soil, the actual importance of such induction and/or selection remains uncertain. Common bacteriological techniques (e.g., isolation on selective media, and plate dilution frequency technique) were used to demonstrate in Cecil A_p soil systems: (1) that PAU bacterial communities in the bulk soil and the rhizosphere of cucumber seedlings were induced and/or selected by mixtures composed of individual phenolic acids at concentrations well below 0.25 mol/g soil; (2) that readily available carbon sources other than phenolic acids, such as glucose, did not modify induction and/or selection of PAU bacteria; (3) that the resulting bacterial communities readily utilize mixtures of phenolic acids as a carbon source; and (4) that depending on conditions (e.g., initial PAU bacterial populations, and phenolic acid concentration) there were significant inverse relationships between PAU bacteria in the rhizosphere of cucumber seedlings and absolute rates of leaf expansion and/or shoot biomass. The decline in seedling growth could not be attributed to resource competition (e.g., nitrogen) between the seedlings and the PAU bacteria in these studies. The induced and/or selected rhizosphere PAU bacteria, however, reduced the magnitude of growth inhibition by phenolic acid mixtures. For a 0.6 mol/g soil equimolar phenolic acid mixture composed of p-coumaric acid, ferulic acid, p-hydroxybenzoic acid, and vanillic acid, modeling indicated that an increase of 500% in rhizosphere PAU bacteria would lead to an approximate 5% decrease (e.g., 20–25%) in inhibition of absolute rates of leaf expansion. As far as we know, this is the first time that such a relationship has been quantified.     

Sampling range of male sweetpotato weevils (Cylas formicarius elegantulus) (Summers) (Coleoptera: Curculionidae) to pheromone traps: Influence of pheromone dosage and lure age

Studies were conducted to determine the effects of sex pheromone dosage and lure age on movement of male sweetpotato weevils (SPW),Cylas formicarius elegantulus (Summers), using mark-release-recapture techniques. SPW trap counts from various downwind distances were compared for dosages ranging from 0.01 to 10.0 g and lure ages ranging from fresh (0 days old) to 64 days old. The percentages of male SPW recaptured decreased with an increase in release distance and decreased with a decrease in dosage at each corresponding distance. Most SPW were caught within the first 16-hr period. Slopes of percent recapture vs. release distance for the two higher dosages (10 g and 1.0 g) differed from those of the two lower dosages (0.1 and 0.01 g) but did not differ from each other. Intercepts were similar among the three higher dosages. Slopes did not differ among the five lure ages examined. Intercepts differed between fresh (0 days old) and 24-day-old septa at 16 hr and between fresh (0 days old) and 34-day-old septa at 40 hr. Previous exposure to pheromone (conditioning) did not increase percentages of SPW recaptured. Results indicate that male SPW are capable of traversing distances of at least 280 m in 16 hr. The pheromone tested in this study appears to be effective at dosages lower than any other coleopteran sex-pheromone system. Incorporation of this pheromone into a SPW management system may effectively reduce the use of insecticides.     

Caste-dependent pheromones in the head of the antTetramorium caespitum

The heads of maleT. caespitum contain 4-methyl-3-hexanol (1.7 g, only the erythro isomer(s) detected) and 4-methyl-3-hexanone (0.8 g). The heads of alate females contain 0.1 g of each compound, whereas only the alcohol (0.1 g) was found in the heads of workers. Both compounds act as attractants for the workers and their possible functions are discussed.'Chargé de Recherche du F.N.R.S.Chercheur qualifié du F.N.R.S.     

Biosynthesis,production site,and emission rates of aggregation-attachment pheromone in males of twoAmblyomma ticks

The aggregation-attachment pheromone componentso-nitrophenol (ONP) and methyl salicylate (MS) in maleAmblyomma variegatum ticks appeared after three days of feeding on the host and reached high values after about six days. Variable quantities of 1.3–7.3 g ONP and about 0.6 g MS were present within ticks. ONP and MS were released at the high rates of 300–1800 ng/hr and 20–600 ng/hr per male tick, respectively. After a temporary decrease, males continued to emit at high rates after nearby attachment of females. InA. hebraeum, ONP showed a similar pattern, but with a delay of about a day. A male, which had fed during 14 days, contained about 2 g and released 225–280 ng/hr. Emission in forcibly detached males of both species dropped rapidly to low levels of less than 10 ng/hr per tick. Host skin and tick feces in the vicinity of feeding males were pheromoneimpregnated. The very high emission rates are consistent with the observations that the pheromone is an important component of the host-location mechanism of conspecifics. ONP and MS are produced in the dermal glands type 2 associated with the ventrolateral cuticle.     

Phytotoxicity of Vulpia Residues: II. Separation, Identification, and Quantitation of Allelochemicals from Vulpia myuros

Phytotoxicity-based extraction and fractionation were employed to separate and purify the allelochemicals from an aqueous extract of vulpia (Vulpia myuros) residues. Further analyses, identification, and quantitation of these allelochemicals were conducted by gas chromatography–mass spectrometry on the most toxic fraction. Twenty-one compounds were identified in the ether fraction from the vulpia residue aqueous extract. They were catechol, hydroquinone, 3,4-dimethoxyphenol, pyrogallol, coniferyl alcohol, and benzoic, succinic, hydrocinnamic, salicylic, protocatechuic, vanillic, gentisic, syringic, p-hydroxybenzoic, -hydroxybenzenepropanoic, p-hydroxyphenylacetic, p-hydroxybenzenepropanoic, hydroferulic, p-coumaric, hydrocaffeic, and ferulic acids. A chromatographic internal standard method with multiple-point calibration graphs was used to quantify the identified compounds. Quantities in the vulpia residues ranged from 1.36 to 81.0 g/g dry residue, in total accounting for 0.05% of the dry weight residue. The combined syringic and hydroferulic acids were present in the largest amount, 140.11 g/g residue. Vanillic, succinic, p-hydroxybenzenepropanoic, and salicylic acids were next in amount, ranging from 37.24 to 81.24 g/g residue. Catechol, hydrocinnamic acid, and hydroquinone were present in the smallest quantities, ranging from 1.36 to 1.82 g/g residue. The remainder of the compounds were intermediate in amount, ranging from 2.33 to 18.1 g/g residue.