Study of neutral lipids ofLupinus mutabilis meal and isolates

Two types of protein isolates have been obtained from defattedLupinus mutabilis meal. The isolates, MA and MB, were obtained by alkaline extraction with 0.2% NaOH and 0.25% sodium bisulfite, respectively, followed by precipitation at the isoelectric point (pH 4.8). Total associated lipids were extracted with 86% ethanol. Neutral lipids were separated in a Florisil column. The lipids in the isolates were similar to those found in the original meal. The following types of compounds were separated, identified, and quantitated: hydrocarbons, waxes, methyl esters, triacylglycerols, free fatty acids, diacylglycerols, and free sterols.     

Beaver (Castor canadensis) responses to major phenolic and neutral compounds in castoreum

North American beaver (Castor canadensis) mark their territories with castoreum, a chemically complex secretion from their castor sacs. The phenolic and neutral fractions of castoreum have been shown to elicit specific behavioral responses from beavers in a field setting. Our objective was to identify compounds/mixtures that evoked responses similar to those stimulated by castoreum. We assayed recently identified phenolic compounds, some phenolics that had been determined to be biologically active in previous studies, the neutral compound borneol, and combinations of phenolic compounds, neutral compounds, and the two combined. Biological activity was measured by the elicitation and extent of specific responses and their strength (duration, frequency, and proportion of beavers responding). Generally, single compounds stimulated fewer responses than mixtures. A 26-compound mixture of phenolic and neutral compounds elicited responses in a similar proportion of trials as castoreum. However, responses to castoreum were stronger than to any synthetic sample. Further investigation of different measures of response, namely, elicitation, completeness, and strength, are deemed necessary to fully decipher the design of social odors.     

Chemical communication in adult schistosomes

Lipids released bySchistosoma mansoni adult males attract females in vitro. Lipid release is modulated by the presence of other worms. AlthoughS. mansoni males release lipid when paired with females, the release is enhanced when they are separated.S. japonicum adults release more free sterols when incubated individually than when incubated together. Similarly, individually incubatedS. haematobium males release more free sterols than when incubated in groups. However,S. haematobium females incubated in groups release more free fatty acids than do equal numbers of males or pairs incubated in groups. There is evidence thatS. mansoni adult females concomitantly accumulate and release cholesterol in the absence of an exogenous supply, although de novo synthesis of cholesterol in schistosomes has not yet been demonstrated. Schistosomula and adult schistosomes incorporate exogenous lipids. Lipids are incorporated chiefly through the tegument. Cholesterol is transferred between males and females.     

Seasonal variation of lipids in femoral gland secretions of male green iguanas (Iguana iguana)

Femoral gland secretions were collected from 21 captive adult male green iguanas (Iguana iguana) in Orotina, Costa Rica, and San Diego, California, during the breeding (November) and nonbreeding (March) seasons. Lipids were extracted with methylene chloride, weighed, separated by thin-layer chromatography, and analyzed by gas chromatography-mass spectrometry. Free and esterified C₁₄-C₂₆ fatty acids, 5-cholestan-3-ol (epico-prostanol), cholest-5-en-3-ol (cholesterol), cholest-5-en-24-methyl-3-ol (campesterol), cholesta-5,22-dien-24b-ethyl-3-ol (stigmasterol), cholesta-8,24(5)-dien-4,4,14-trimethyl-3-ol (lanosterol), cholest-5-en-24-ethyl-3-ol (-sitosterol), and two uncharacterized sterols were indicated. More lipids were recovered from femoral gland secretions obtained during the breeding than the nonbreeding months, indicating that secretion deposits may be more detectable during the mating season.     

Identification of a sex pheromone ofHeliothis subflexa (GN.) (Lepidoptera: Noctuidae) and field trapping studies using different blends of components

Eight compounds were isolated from the sex pheromone gland ofHeliothis subflexa (Gn.) and identified as hexadecanal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-7-hexadecen-1-ol acetate, (Z)-9-hexadecen-1-ol acetate, (Z)-11-hexadecen-1-ol acetate, (Z)-9-hexadecen-1-ol, and (Z)-11-hexadecen-1-ol. Although the whole blend was found to be an effective male attractant, the deletion of alcohols from the blend increased trap captures considerably. Further, although the binary mixture of (Z)-9-hexadecenal and (Z)-11-hexadecenal caught some maleH. subflexa, significant increases in captures were noted when the three acetate components were included in the blend.Mention of a commercial or proprietary product in this paper does not constitute an endorsement of that product by the USDA or the State of Florida.     

Poly(neutral red) as a NAD reduction catalyst and a NADH oxidation catalyst: Towards the development of a rechargeable biobattery

In this paper, we have established that poly(neutral red), PNR, functions as an electrocatalyst for the reduction and oxidation of NAD⁺/NADH in a rechargeable biobattery environment. The reversibility of this catalyst was possible only with the addition of Zn²⁺ for complexation to the redox polymer. The zinc ion complexation with the polymer facilitates electron and proton transfer to/from the substrate and the NAD⁺/NADH coenzyme without forming covalent bonds between the nicotinamide and the substrate surface. This research presents use of this reversible catalyst in a rechargeable biobattery. The rechargeable battery includes a Prussian blue cathode and a bioanode including NAD⁺-dependent alcohol dehydrogenase and zinc complexed PNR. This bioanode was coupled to the cathode with Nafion^® 212 acting as the ion exchange membrane separator between the two compartments. The biobattery has an open circuit potential of 0.545(±0.009) V when first assembled and 0.053(±0.005) V when fully discharged. However, when fully charged, the biobattery has an open circuit potential of 1.263(±0.051) V, a maximum power density of 16.3(±4.03) μW cm⁻³ and a maximum current density of 221(±13.2) μA cm⁻³. The efficiency and stability of the biobattery were studied by cycling continuously at a discharging rate of 1 C and the results obtained showed reasonable stability over 50 cycles.     

Liver lipids and fatty acids of the sting ray Dasyatis bleekeri (Blyth)

The sting ray, Dasyatis bleekeri (Blyth), has been studied for lipids and fatty acids of its liver. The neutral lipids identified were hydrocarbons, wax esters, steryl esters, 1-O-alkyl-2,3-diacylglycerols, triacylglycerols, and sterols. Neutral lipids were predominant (91.8%), major components being triacylglycerols (92.7%). Polyenoic fatty acids of n-3 series, viz. eicosapentaenoic acid and docosahexaenoic acid, were high in the phospholipid and neutral lipid fractions. Cholesterol was the major component (67.9%) in the steryl ester fraction. Glyceryl ethers, with chainlengths up to 30 carbons, were recorded with unsaturated, anteiso, iso, and normal chains. In wax ester alcohols, up to 32-carbon chains were recorded. Hydrocarbons were up to 36-carbon chains with anteiso, iso, and normal chains. Among branched chain hydrocarbons, pristane was the major component (6.7%) and squalene was present at the level of 3.5%. Chimyl and batyl alcohol backbones were the major components found in 1-O-alkyl-diacylglycerols.     

Analysis of gular and paracloacal gland secretions of the american alligator (Alligator mississippiensis) by thin-layer chromatography Gland,sex, and individual differences in lipid components

Secretions from the gular and the paracloacal glands of adult male and female American alligators (Alligator mississippiensis) were extracted with chloroform, weighed, and analyzed by thin-layer chromatography. In both sexes, more lipoidal secretions were recovered from the paracloacal glands than from the gular glands. Females produce more lipoidal secretions in both sets of glands than do males. The thin-layer chromatograms of extracts from both glands exhibit bands consistent with aliphatic alcohols, sterols, free fatty acids, and steryl esters. Triglycerides, hydrocarbons, phosphatidylethanolamine, and lysophosphatidylcholine also are indicated in some chromatograms. Gland, sex, and individual differences are suggested in the thinlayer profiles.     

Influence of mustelid semiochemicals on population dynamics of the deer mouse (Peromyscus maniculatus)

The influence of mustelid anal-gland compounds on population dynamics of the deer mouse (Peromyscus maniculatus) was investigated. Densities of deer mice were not found to be significantly different between treated and control areas. However, on average, numbers of deer mice were lower on treated areas following the July treatments of 1991 and 1992. Survival rates appeared to be lower and more erratic on treated than control areas in 1991; however, there were no statistically significant differences. Reproduction appeared to be unaffected by the odors. We concluded that deer mice did not display a behavioral response to weasel odors. We speculated that decreases in densities were owing to predation by weasels, which were attracted to the odors on treated sites. We also concluded that the use of weasel odors as a biological control method for voles (Microtus spp.) would likely have little impact on deer mice (a nontarget species).     

Olfactory Responses of the Predatory Mites (N eoseiulus cucumeris) and Insects (O rius strigicollis ) to Two Different Plant Species Infested with Onion Thrips (T hrips tabaci)

Responses of Neoseiulus cucumeris (a predatory mite) and the predatory insect Orius strigicollis to volatiles associated with two different plant species infested with onion thrips, Thrips tabaci, were examined in a Y-tube olfactometer. Both predators species showed a significant preference for volatiles from infested cucumber leaves without T. tabaci over clean air. However, they were not attracted to volatiles from uninfested cucumber leaves, artificially damaged cucumber leaves, or volatiles from T. tabaci plus their visible products collected from cucumber leaves. These results suggest that both predator species are capable of exploiting herbivore-induced volatiles from T. tabaci-infested cucumber leaves as a foraging cue. Neither predator was attracted to volatiles from uninfested spring onion leaves, infested spring onion leaves without T. tabaci, or volatiles from T. tabaci plus their visible products collected from spring onion leaves. Interestingly, they avoided volatiles from artificially damaged spring onion leaves. A possible explanation for the non-significant olfactory responses of the predator species to spring onion plants with infestation damage of T. tabaci is discussed.     

Estimation of single furniture carpet beetle (Anthrenus flavipes LeConte) sex pheromone release by dose-response curve and chromatographic analysis of pentafluorobenzyl derivative of (Z)-3-decenoic acid

A single-insect aeration apparatus was designed for the study of the pheromone release rate of furniture carpet beetlesAnthrenus flavipes LeConte. Tenax® was selected as the pheromone adsorption agent. The quantity of (Z)-3-decenoic acid (A. flavipes female pheromone) produced per day was estimated by a dose-response curve and bioassay of the collected pheromone. A procedure was established to quantitatively determine the furniture carpet beetle pheromone involving pentafluoro-benzylation of (Z)-3-decenoic acid and subsequent gas chromatographic analysis utilizing flame-ionization and electron-capture detectors.Coleoptera: Dermestidae. Mention of a commercial or proprietary product in this paper does not constitute a recommendation of this product by the USDA.Research supported by College of Agriculture and Life Sciences, University of Wisconsin-Madison; a cooperative agreement between the University of Wisconsin and USDA SEA; grants from Research Board and School of Life Science of the University of Illinois-Urbana; and by a Grant-in-Aid of Research from Sigma Xi.     

Oxidative stability of structured lipids produced from borage (<Emphasis Type="Italic">Borago officinalis</Emphasis> L.) and evening primrose (<Emphasis Type="Italic">Oenothera biennis</Emphasis> L.) oils with docosahexaenoic acid

This study utilized γ-linolenic acid (18∶3n−6; GLA)-rich borage oil (BO) and evening primrose oil (EPO) for the synthesis of structured lipids (SL) and compared the oxidative stability of the products with those of unmodified BO and EPO as controls. Immobilized Novozym 435 lipase from Candida antarctica was used as the biocatalyst for SL production. BO or EPO eas enzymatically modified with docosahexaenoic acid (22∶6n−3; DHA), as the acyl donor, to produce SI. The SI were characterized and their oxidative stabilities evaluated. Among the oils examined, SL gave rise to higher quantities (P≤0.05) of conjugated dienes, TBARS, and headspace volatiles as compared to their unmodified counterparts. Results indicated that modified oils were less stable than their unmodified counterparts. The double bond index (DBI) and methylene bridge index (MBI) of oils decreased (P<0.05) during oxidation in the more unsaturated oils. An attempt was made to correlate various parameters of oxidation with DBI and MBI of oils; correlation coefficients (−r) were within the range of 0.574–0.973. This suggests that indicators such as DBI and MBI can reflect oxidative stability of oils.     

The pheromone of the eastern tent caterpillar,Malacosoma americanum (F.) (lepidoptera,Lasiocampidae)

The pheromone system of the eastern tent caterpillar,M. americanum, has been identified as a mixture of (E,Z)-5,7-dodecadienal and the corresponding alcohol. Field data on the attractiveness of the aldehyde alone were not consistent, but mixtures of aldehyde and alcohol in varying proportions were attractive to males. Addition of small amounts ofE,Z acetate toE,Z aldehyde had no effect on male response, but larger amounts reduced trap catch. Traps baited withZ,E, E,E, orZ,Z aldehydes were not more attractive than blank traps. Pherocon IC traps fortified with extra adhesive and baited with lures consisting of 500 µg (E,Z)-5,7-dodecadienal with either 250 or 100 µg of the corresponding alcohol trapped as many as 100 males/trap/night with means of 15–20. Lures prepared from purified (94%E,Z) aldehyde and alcohol were more attractive than those prepared from unpurified (58%E,Z) materials.DeceasedMention of a company name or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture.     

Aphrodisiac pheromones of the sulfur butterfliesColias eurytheme andC. Philodice (Lepidoptera,Pieridae)

Male wing compounds involved in maintaining reproductive isolation between the sulfur butterfliesColias eurytheme andC. philodice have been identified. MaleC. philodice produce threen-hexyl esters; myristate, palmitate, and stearate, which are absent inC. eurytheme. A branched hydrocarbon, 13-methylheptacosane, is found on the wings of maleC. eurytheme, but notC. philodice. Several straight-chain hydrocarbons are on the wings of both species. The esters and 13-methylheptacosane have significant electrophysiological activity. Preliminary behavioral experiments indicate that the esters (especiallyn-hexyl myristate) function as species-recognition signals. The esters and 13-methylheptacosane also have low-to-moderate aphrodisiac activity.     

Catalytic activity of (CaO)1−x(ZnO)x solids for the N2O decomposition: relation with photoluminescence

(CaO)_1–x (ZnO) _x mixed oxides (x=0–1), heated at 1423 K under atmospheric conditions, were checked for their catalytic activity in the N₂O decomposition in the temperature range of 450–650°C. Although the catalytic activity was measured in the dark, it was found to be linearly related with the photoluminescence intensity of the catalysts.     

Mediation of host selection by cuticular hydrocarbons in the honeybee tracheal MiteAcarapis woodi (Rennie)

Using a simple two-choice bioassay and video analysis of individual locomotory tracks, it was determined that a preference for young-bee hosts over old-bee hosts in female honeybee tracheal mites,Acarapis woodi (Rennie), is chemically mediated. When presented with a choice of cuticular extracts from 5-day-old and <1-day-old adult bees, mites showed a significant preference for the young-bee extract in three of four bee colony sources. This discrimination was due apparently to a greater positive response elicited by the young-bee extract rather than a deterrent effect of old-bee extract, as the extract of old bees evoked a significantly higher response than a hexane control. A bioassay of silica-gel fractions of young-bee extract indicated that cuticular hydrocarbons alone were responsible for tracheal mite response. Further fractionation of a hydrocarbon fraction by argentation chromatography demonstrated that both saturated and unsaturated hydrocarbons were involved in the mite response, but when presented in opposition, mites showed a stronger response to the saturated than to the unsaturated components. Mites placed in zones treated with cuticular extract of young bees exhibited higher angular velocities than those placed on hexane, causing them to remain in the extract-treated zones for extended periods. These results point to a possible control strategy whereby migration of tracheal mites to young-bee hosts could be disrupted by artificially altering the chemical profile of the honeybee cuticle.     

Influence of white pine watering regimes on feeding preferences of spring and fall adults of the white pine weevilPissodes strobi (Peck)

Spring and fall adults of the white pine weevil,Pissodes strobi (Peck), were exposed in no-choice and two-choice tests to bark from water-stressed and non-water-stressed white pine (Pinus strobus L.), which had also been exposed or not exposed to weevil attack. This experiment demonstrated that the weevils could discriminate between bark from water-stressed white pine and preferred bark from the nonstressed plants. The weevils also preferred bark from nonstressed plants that were previously exposed to weevil damage. Spring and fall adults displayed the same feeding preferences. No sex differences were found in feeding preferences. Less nitrogen, phosphorus, and potassium were found in bark from the nonstressed plants, and the potassium level was higher in damaged plants. We expect that the biological performance of the weevil should be favored by vigorously growing plants rather than by stressed plants.     

Host selection behavior of bark beetles (Coleoptera: Scolytidae) attackingPinus ponderosa,with special emphasis on the western pine beetle,Dendroctonus brevicomis

Detection of weakened hosts from a distance by bark beetles through olfaction was investigated in field experiments. No significant numbers of Scolytidae were attracted to anaerobically treated pine bolts, stem disks, or sugar and ponderosa pine bark including phloem. Treatment of living trees with cacodylic acid induced attacks byDendroctonus brevicomis, D. ponderosae, Ips latidens, Gnathotrichus retusus, andPityophthorus scalptor, beginning two weeks after treatment. There was no significant difference between landing rates ofD. brevicomis andD. ponderosae on screened treated trees and screened controls. There was a significant increase in landing rates ofG. retusus andI. latidens, because both species had penetrated the screen and produced pheromones. Tree frilling alone did not increase the landing rate of bark beetles. Freezing of the lower trunk with dry ice did not increase significantly the landing rate ofD. brevicomis, D. ponderosae, G. retusus, orI. latidens on screened trees, whereas unscreened frozen trees were attacked by all four species. There was no significantly higher landing rate byD. brevicomis, D. ponderosae, I. paraconfusus, I. latidens, G. retusus, orHylurgops subcostulatus on screened trees evidencing symptoms of severe infection by the root pathogenVerticicladiella wagenerii, than on symptornless trees. These experiments show thatD. brevicomis, D. ponderosae, I. paraconfusus, I. latidens, andG. retusus land, apparently indiscriminately, on healthy and stressed hosts. Thus, in these species host discrimination must occur after landing and prior to sustained feeding.These studies were supported in part by the U.S.D.A. Forest Service, Cooperative State Research Services (2598-RRF.W-1 10) and the National Science Foundation and Environmental Protection Agency through a grant (NSF GB-34719/BM575-04223) to the University of California; and by the Canada Department of the Environment. The findings, opinions and recommendations are not necessarily those of the University of California or the funding agencies.From a thesis submitted by H.A. Moeck to the University of California, Berkeley, in partial fulfillment of the requirements for the degree Doctor of Philosophy in Entomology.     

Copolymerization of N-(4-carboxyphenyl)maleimide with acrylonitrile and the properties of its membrane

N-(4-Carboxyphenyl)maleimide (N-4-CPMI, M₁) was copolymerized with acrylonitrile (AN, M₂) to prepare the copolymer. The monomer reactivity ratios and Alfrey-Price Q, e values were determined as r₁ = 0.56, r₂ = 0.84, Q ₁ = 2.0, Q ₂ = 0.6 and e ₁ = 2.06, e ₂ = 1.2. The membrane of copolymer containing 0.25% CPMI had a good tensile property (67.3 MPa). The 0.75 mole% membrane had an excellent selectivity factor (α = 45.3).     

Castor sacs and anal glands of the north american beaver (Castor canadensis): their histology,development, and relationship to scent communication

Both sexes of beavers possess a pair of castor sacs and a pair of anal glands located in paired subcutaneous cavities between the pelvis and the base of the tail. The castor sacs are not glandular in the histological sense, hence references to these structures as preputial glands or castor glands are misnomers. The wall of the castor sacs is plicate and comprised of three distinct zones: an outer layer of vascular connective tissue, a two-to five-cell-thick layer of mitotic epithelial cells, and several densely packed layers of cornified epithelium which grade into more widely separated sheets toward the lumen. Monocultures of a gram-positive facultatively anaerobic bacterium were present in the lumen of all castor sac preparations. Differences in the frequency of castoreum deposition were not attributable to differences in the structure of the castor sacs. The anal glands of beavers are holocrine sebaceous glands. These glands develop more rapidly than the castor sacs. Anal gland tissue from embryos exhibited cellular characteristics associated with the production of sebum. Secretory activity was evident in all preparations. The relationship of castoreum and anal gland secretion to scent communication among beavers is discussed.