bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Fluid Dynamics Prediction of Blood Damage in a Centrifugal Pump
Authors: Song Xinwei , Throckmorton Amy L. , Wood Houston G. , Antaki James F. , Olsen Don B.
Published: October 2003

Abstract: This study explores a quantitative evaluation of blood damage that occurs in a continuous flow left ventricular assist device due to fluid stress. Computational fluid dynamics (CFD) analysis is used to track the shear stress history of 388 particle streaklines. The accumulation of shear and exposure time is integrated along the streaklines to evaluate the levels of blood trauma. This analysis, which includes viscous and turbulent stresses, provides a statistical estimate of possible damage to cells flowing through the pump. In vitro normalized index of hemolysis values for clinically available ventricular assist devices were compared to our damage indices. This allowed for an order of magnitude comparison between our estimations and experimentally measured hemolysis levels, which resulted in a reasonable correlation. This work ultimately demonstrates that CFD is a convenient and effective approach to analyze the Lagranian behavior of blood in a heart assist device.
Axial Type Self‐Bearing Motor for Axial Flow Blood Pump
Authors: Okada Yohji , Masuzawa Toru , Matsuda Ken‐Ichi , Ohmori Kunihiro , Yamane Takashi , Konishi Yoshiaki , Fukahori Shinya , Ueno Satoshi , Kim Seung‐Jong
Published: October 2003

Abstract: An axial self‐bearing motor is proposed which can drive an axial blood pump without physical contact. It is a functional combination of the bi‐directional disc motor and the axial active magnetic bearing, where it actively controls single degree‐of‐freedom motion, while other motions such as lateral vibration are passively stable. For application to a blood pump, the proposed self‐bearing motor has the advantages of simple structure and small size. Through the finite element method (FEM) analysis and the experimental test, its good feasibility is verified. Finally, the axial flow pump is fabricated using the developed magnetically suspended motor. The pump test is carried out and the results are discussed in detail.
Building a Computer Model of the Haemobear Blood Pump
Authors: Grönsfelder Thomas , Schima Heinrich , Reindl Christian , Nordmann Rainer
Published: October 2003

Abstract: Further development of the Haemobear blood pump requires theoretical predictions of the dynamic behavior of the rotor. These predictions can be used to compare different rotor geometry at desired operating conditions before a prototype is built. The study focuses on a rotor‐dynamic model of the rigid rotor with six degrees of freedom (6‐DoF), which is implemented using the Matlab‐Simulink software package. The forces acting on the rotor are provided to Simulink in terms of constant values (e.g., gravity force), linear coefficients, or nonlinear functions. These coefficients or functions are obtained using numerical simulation results. Fluid forces and magnetic forces can be calculated using commercial software codes. The output of these codes has to be postprocessed to get the desired values for Simulink. This article will give an overview of how to implement arbitrary physical influences on the rotor in a computational model of the complete pump.
An Estimation Method of Hemolysis within an Axial Flow Blood Pump by Computational Fluid Dynamics Analysis
Authors: Yano Tetsuya , Sekine Kazumitsu , Mitoh Ayumi , Mitamura Yoshinori , Okamoto Eiji , Kim Dong‐Wook , Nishimura Ikuya , Murabayashi Shun , Yozu Ryohei
Published: October 2003

Abstract: Evaluation of hemolysis within a blood pump on a computer is useful for developing rotary blood pumps. The flow fields in the axial flow blood pump were analyzed using computational fluid dynamics (CFD). A blood damage index was calculated based on the changes in shear stress with time along 937 streamlines. Hemolysis of the pumps was measured using bovine blood. A good correlation between the computed and measured hemolysis results was observed. CFD analysis is useful for estimating hemolysis of rotary blood pumps on a computer.
Development of a Magnetic Fluid Shaft Seal for an Axial‐Flow Blood Pump
Authors: Sekine Kazumitsu , Mitamura Yoshinori , Murabayashi Shun , Nishimura Ikuya , Yozu Ryouhei , Kim Dong‐Wook
Published: October 2003

Abstract: A rotating impeller in a rotary blood pump requires a supporting system in blood, such as a pivot bearing or magnetic suspension. To solve potential problems such as abrasive wear and complexity of a supporting system, a magnetic fluid seal was developed for use in an axial‐flow blood pump. Sealing pressures at motor speeds of up to 8,000 rpm were measured with the seal immersed in water or bovine blood. The sealing pressure was about 200 mm Hg in water and blood. The calculated theoretical sealing pressure was about 230 mm Hg. The seal remained perfect for 743 days in a static condition and for 180+ days (ongoing test) at a motor speed of 7,000 rpm. Results of measurement of cell growth activity indicated that the magnetic fluid has no negative cytological effects. The specially designed magnetic fluid shaft seal is useful for an axial‐flow blood pump.
Effect of Angular Error on Tissue Doppler Velocities and Strain
Authors: Storaa Camilla , Åberg Peter , Lind Britta , Brodin Lars‐Åke
Published: October 2003

One of the major criticisms of ultrasound Doppler is its angle dependency, that is its ability to measure velocity components directly to or from the transducer only. The present article aims to investigate the impact of this angular error in a clinical setting. Apical two‐ and four‐chamber views were recorded in 43 individuals, and the myocardium was marked by hand in each image. We assume that the main direction of the myocardial velocities is longitudinal and correct for the angular error by backprojecting measured velocities onto the longitudinal direction drawn. Strain was calculated from both corrected and uncorrected velocities in 12 segments for each individual. The results indicate that the difference between strain values calculated from corrected and uncorrected velocities is insignificant in 5 segments and within a decimal range in 11 segments. The biggest difference between measured and corrected strain values was found in the apical segments. Strain is also found to be more robust against angular error than velocities because the difference between corrected and uncorrected values is smaller for strain. Considering that there are multiple sources of noise in ultrasound Doppler measurements, the authors conclude that the angular error has so little impact on longitudinal strain that correction for this error can safely be omitted. (ECHOCARDIOGRAPHY, Volume 20, October 2003)
Live Three‐Dimensional Transthoracic Echocardiographic Identification of Discrete Subaortic Membranous Stenosis
Authors: Agrawal Gopal G. , Nanda Navin C. , Htay Thein , Dod Harvinder S. , Gandhari Sujit R.
Published: October 2003

We describe an adult patient in whom live three‐dimensional transthoracic echocardiography illustrated the exact site and full extent of the subaortic membrane as well as the narrow opening within the membrane, indicative of severe stenosis. To our knowledge this has not been reported previously. (ECHOCARDIOGRAPHY, Volume 20, October 2003)
Real‐Time Three‐Dimensional Echocardiography Using a Novel Matrix Array Transducer
Authors: Sugeng Lissa , Weinert Lynn , Thiele Karl , Lang Roberto M.
Published: October 2003

Three‐dimensional echocardiography has multiple advantages over two‐dimensional echocardiography, such as accurate left ventricular quantification and improved spatial relationships. However, clinical use of three‐dimensional echocardiography has been impeded by tedious and time‐consuming methods for data acquisition and post‐processing. A newly developed matrix array probe, which allows real‐time three‐dimensional imaging with instantaneous on‐line volume‐rendered reconstruction, direct manipulation of thresholding, and cut planes on the ultrasound unit may overcome the aforementioned limitations. This report will review current methods of three‐dimensional data acquisition, emphasizing the real‐time methods and clinical applications of the new matrix array probe. (ECHOCARDIOGRAPHY, Volume 20, October 2003)
Interpretation of Left Ventricular Wall Motion During Stress Testing
Authors: DeCara Jeanne M. , Lang Roberto M.
Published: October 2003

This article describes the obstacles to stress echocardiographic interpretation, and reviews the techniques currently available that offer a more objective approach to stress wall motion analysis than the conventional visual methodology. These techniques include Doppler‐based methods, such as myocardial Doppler velocity and strain rate imaging, as well as automated border detection techniques, such as acoustic quantification and color kinesis. (ECHOCARDIOGRAPHY, Volume 20, October 2003)
New Techniques for the Assessment of Regional Left Ventricular Wall Motion
Authors: Garcia‐Fernandez Miguel Angel , Bermejo Javier , Perez‐David Esther , Lopez‐Fernandez Teresa , Ledesma Maria Jesus , Caso Pio , Malpica Norberto , Santos Andres , Moreno Mar , Desco Manuel
Published: October 2003

The assessment of regional left ventricular (LV) function has been an important yet unresolved problem since the introduction of echocardiography as a diagnostic tool. Abnormal regional LV wall motion is an early finding in multiple cardiac pathologies and its diagnosis is of critical importance. In the last few years diagnostic procedures based on combined use of existing echocardiographic technologies were geared toward improving the accuracy of detection of baseline and/or induced regional wall motion abnormalities. One of the assumptions is that the combination of reduced LV wall thickening and reduced myocardial velocities can be used to accurately diagnose regional myocardial dysfunction. In this article we will discuss several new techniques for the quantification of regional LV function using Doppler echocardiography. (ECHOCARDIOGRAPHY, Volume 20, October 2003)
The population genetics of the apple maggot fly, Rhagoletis pomonella and the snowberry maggot, R. zephyria: implications for models of sympatric speciation
Authors: Feder Jeffrey L. , Williams Scott M. , Berlocher Stewart H. , McPheron Bruce A. , Bush Guy L.
Published: October 2003

True fruit flies belonging to the Rhagoletis pomonella (Diptera:Tephritidae) sibling species complex possess several attributes consistent with a history of sympatric divergence via host plant shifts. Here, we investigate whether hybridization and genetic introgression is occurring between two members of the group, Rhagoletis pomonella (Walsh), whose primary hosts are domestic apples (Malus pumila) and hawthorns (Crataegus spp., and R. zephyria (Snow) whose host is snowberries (Symphoricarpos spp.). These flies are important because they appear to be at a transition stage between taxa reproductively isolated solely on the basis of host plant‐related adaptations and those that have evolved additional non‐host dependent sterility and inviability. Observing extensive hybridization and introgression between R. pomonella and R. zephyria would have major repercussions for current models of sympatric speciation.

In a survey of allozyme and mitochondrial DNA (mtDNA) variation for 1105 flies collected throughout the northern United States we found two results suggesting that low level hybridization occurs between R. pomonella and R. zephyria. (1) Two flies reared from snowberries and one fly reared from hawthoms had genotypes indicative of them being R. pomonella and R. zephyria, respectively. Rhagoletis pomonella and R. zephyria adults may therefore occasionally frequent each others host plant, providing the opportunity for hybridization. (2) Four flies collected from hawthorns and one from snowberries had genotypes that made them likely to be F1 hybrids.

Likelihood analysis revealed the data were also consistent with an hypothesis of shared ancestral alleles (i.e., the pattern of genetic variation could also be explained by R. pomonella and R. zephyria sharing alleles/haplotypes whose origins date to a common ancestor). We estimated that, in the absence of interspecific mating, random assortment of genes within R. pomonella and R. zephyria populations would produce an average of 5.4 flies with genotypes suggesting they were F1 hybrids – a number equivalent to the 5 putative F1 hybrids observed in the study. Our results therefore underscore the difficulty in distinguishing between hypotheses of low level introgression and shared ancestral polymorphism. But even if hybridization is occurring, the data suggest that it is happening at a very low and probably evolutionarily insignificant level (perhaps 0.09% per generation), consistent with sympatric speciation theory. Future tests are discussed that could help resolve the hybridization issue for R. pomonella and R. zephyria.
Freezing‐altered palatability of Bradford pear to Japanese beetle: evidence for decompartmentalization and enzymatic degradation of feeding deterrents
Authors: Keathley Craig P. , Potter Daniel A. , Houtz Robert L.
Published: October 2003

The basis for resistance of Bradford callery pear, Pyrus calleryana Decaisne ‘Bradford,’ [Rosaceae] to the Japanese beetle, Popillia japonica Newman, was investigated. Chloroform‐dipping rendered leaves palatable, initially suggesting that deterrent waxes had been removed. However, extracts containing surface waxes were not deterrent. Subsequent experiments showed that increased palatability of solvent‐dipped leaves is associated with enzymatic tissue browning, characteristic of polyphenol oxidases, rather than simply release of phagostimulants from surface disruption of damaged leaves. Frozen and thawed leaves showed similar browning, becoming increasingly palatable for several hours after thawing. Palatability changes were temperature‐ and aerobic‐sensitive, further evidence that oxidizing enzymes are involved. Juice from leaves that had been frozen and thawed stimulated feeding on glass fiber disks, whereas fresh leaf juice did not. Survival and fecundity were much higher for beetles fed frozen and thawed or chloroform‐dipped Bradford pear leaves than for beetles fed normal leaves. We hypothesize that decompartmentalization of deterrent compounds, possibly phenolics, followed by enzymatic oxidation and altered leaf chemistry may explain the increased palatability of chloroform‐dipped or frozen and thawed Bradford pear tissue to P. japonica. This approach may be helpful in identifying specific compounds responsible for resistance of woody plants to generalist insects.
Trichogramma egg parasitism of Helicoverpa armigera on pigeonpea and sorghum in southern India
Authors: Romeis J. , Shanower T.G. , Zebitz C.P.W.
Published: October 2003

Trichogramma spp. (Hymenoptera: Trichogrammatidae) only rarely parasitize eggs of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on pigeonpea (Cajanus cajan (L.) Millspaugh), while on other plants including sorghum (Sorghum bicolor (L.)) high parasitism levels of this host are found. In this study two strategies designed to increase the parasitoid activity on pigeonpea were tested in the field: intercropping pigeonpea with sorghum and mass‐releasing T. chilonis Ishii. Neither strategy led to an increase in parasitism. On pigeonpea, H. armigera oviposited >74.8% of its eggs on calyxes and pods. Parasitism levels in host eggs collected from different plant structures varied significantly with 3.6, 0.3, and 40.7% of eggs on calyxes, pods, and leaves parasitized. Earlier studies have shown that calyxes and pods possess long glandular and non‐glandular trichomes, and are covered by sticky trichome exudates which inhibit parasitoid searching behaviour. Parasitism levels between 27.9 and 100% were recorded from host eggs on the intercropped sorghum. Trichogramma chilonis was the dominant parasitoid species. The mean clutch size was 2.03, but up to six parasitoids emerged per egg. Progeny sex ratio (% females) decreased with clutch size, from 63.1% at a clutch size of one to 46.0% at a clutch size of five. Sticky trap catches showed that while the parasitoid population in sorghum increased when H. armigera started ovipositing, the population within pigeonpea did not benefit from either a high parasitoid population in sorghum or a high host egg density on pigeonpea. During one of five seasons studied, however, high parasitism levels (up to 73%) were recorded on pigeonpea. During this season, H. armigera oviposited on pigeonpea plants in the vegetative growth stage and a high proportion of eggs were collected from leaves. Parasitism levels were positively correlated with the percentage of eggs collected from leaves. This study shows that the parasitization efficiency of Trichogramma spp. on pigeonpea depends mainly on the location of the host eggs. This explains why parasitism levels of H. armigera eggs on pigeonpea did not increase when intercropped with sorghum or after mass‐releasing T. chilonis.
Modifications in dispersal and oviposition of Bt‐resistant and Bt‐susceptible Colorado potato beetles as a result of exposure to Bacillus thuringiensis subsp. tenebrionis Cry3A toxin
Authors: Alyokhin Andrei V. , Ferro David N.
Published: October 2003

Laboratory strains of Colorado potato beetle, Leptinotarsa decemlineata (Say), physiologically resistant and susceptible to Bacillus thuringiensis (Berliner) subsp. tenebrionis Cry3A toxin were reared to adults on caged potato plants. Influence of three different diets (transgenic potatoes, regular potatoes, and regular potatoes followed by the transgenic potatoes) on beetle mortality, fecundity, and flight behavior were tested under laboratory conditions. A computer‐linked flight mill system was used to quantify beetle flight, and dissections were performed to determine the level of flight muscle development. Susceptible beetles continuously fed on transgenic foliage suffered heavy mortality, did not develop flight muscles, and did not produce any eggs. Resistant beetles continuously fed on transgenic foliage were capable of flight and reproduction; however, it took them longer to initiate flight behavior, and their fecundity was lower than fecundity of other treatments. In both strains, detrimental effects became significantly less severe when the beetles were allowed to feed on regular foliage prior to toxin ingestion. In the resistant strain, ingestion of Cry3A toxin significantly increased flight activity, indicating that physiological resistance was probably reinforced by the behavioral escape from toxic environments. No such response was observed for susceptible beetles. When fed on regular foliage, resistant Colorado potato beetles engaged in significantly fewer flights than susceptible beetles. Behavioral differences between resistant and susceptible beetles observed in the present study are likely to affect gene flow between transgenic crops and adjacent refugia, and should be taken in consideration when designing resistance management plans for transgenic potato crops.
Olfactory conditioning of the proboscis extension in bumble bees
Authors: Laloi D. , Sandoz J.C. , Picard‐Nizou A.L. , Marchesi A. , Pouvreau A. , Taséi J.N. , Poppy G. , Pham‐delègue M.H.
Published: October 2003

The foraging behaviour of bumble bees is well documented for nectar and/or pollen gathering, but little is known about the learning processes underlying such behaviour. We report olfactory conditioning in worker bumble bees Bombus terrestris L. (Hymenoptera: Apidae) obtained under laboratory conditions on restrained individuals. The protocol was adapted from the proboscis extension conditioning previously described in the honey bee Apis mellifera L. Bumble bees were found to be able to learn a pure odorant when it was presented in paired association with a sugar reward, but not when odour and reward were presented in an explicitly unpaired procedure. This suggests an associative basis for this olfactory learning. Bumble bees showed similar conditioning abilities when stimulated with two different floral odours. An effect of the sugar reward concentration on the learning performances was found.
Effect of avocadofurans on larval survival, growth, and food preference of the generalist herbivore, Spodoptera exigua
Authors: Rodriguez‐Saona Cesar R. , Trumble John T.
Published: October 2003

We examined the effect of two avocadofurans, 2‐(pentadecyl)furan and 2‐(heptadecyl)furan, from avocado idioblast oil cells on maturation and larval feeding behavior of a generalist insect herbivore, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae). Experiments were conducted using two larval sizes: early‐stadium larvae refer to those larvae from experiments initiated with neonates while late‐stadium larvae refer to those larvae from experiments initiated with third instars. In order to use selected sublethal doses for developmental and behavioral studies on early‐ and late‐stadium larvae, log‐dose probit lines were determined using diet incorporation bioassays. Both avocadofurans had similar toxicities to early‐stadium larvae [LC50= 2.2 and 1.9 μmoles/g of diet for 2‐(pentadecyl)furan and 2‐(heptadecyl)furan, respectively] and late‐stadium larvae (LC50= 3.0 and 3.4 μmoles/g of diet, respectively). In diet bioassays extending from egg hatch to adult emergence, the avocadofurans significantly prolonged larval developmental times and reduced S. exigua pupal weights. In 7 d no‐choice bioassays initiated with cohorts of newly‐molted third instars, the avocadofurans significantly reduced larval weights at various sublethal concentrations (below LC50 values). To test larval feeding deterrence effects of these avocadofurans, choice tests were conducted using early and older instar larvae. A significantly higher proportion of early‐stadium larvae preferred control diet over diet treated with either avocadofuran at several sublethal concentrations. Similarly, choice tests with late‐stadium larvae showed greater proportions of larvae on control diet than treated diet even at concentrations below the LC50. Moreover, late‐stadium larvae consumed significantly more of the control diet than the treated diet. Thus, the avocadofurans may act as feeding deterrents as well as toxicants in plant protection against non‐adapted insect herbivores.
Effect of an ecdysteroid agonist, tebufenozide, on the completion of diapause in susceptible and resistant strains of the codling moth, Cydia pomonella
Authors: Sauphanor Benoît , Bouvier Jean‐Charles , Brosse Véronique
Published: October 2003

Codling moth Cydia pomonella (L.) (Lepidoptera, Tortricidae) larvae kept under a short photoperiod enter a diapause which can be broken by exposure to 25 °C following an extended chilling period. We investigated the effects of the ecdysteroid agonist tebufenozide on the diapause of this species, both on a laboratory strain susceptible to insecticides and two strains selected for resistance to diflubenzuron or deltamethrin. The treatment induced moulting by breaking diapause of the susceptible strain when applied at the end of the growth period, or by reducing the pre‐emergence period when applied after chilling. The strains exhibiting resistance in the neonate instar were also resistant to the ecdysteroid agonist applied to diapausing larvae, indicating that mechanisms of resistance remained active during this arrest of development. High doses of tebufenozide were lethal for the most resistant insects, but neither reduced the pupation delay nor produced the larval‐pupal moults which occur in the susceptible strain. As diapausing larvae of C. pomonella can be easily collected, the expression of resistance to tebufenozide both in the target instar, i.e. neonates, and during diapause may contribute to early detection of resistance to this insecticide in field populations.
Effects of augmentative releases of eggs and larvae of the ladybird beetle, Adalia bipunctata, on the abundance of the rosy apple aphid, Dysaphis plantaginea, in organic apple orchards
Authors: Wyss Eric , Villiger Mathias , Hemptinne Jean‐Louis , Müller‐schärer Heinz
Published: October 2003

The impact of augmentative releases of larvae and eggs of the indigenous ladybird beetle Adalia bipunctata (L.) (Coleoptera: Coccinellidae) against the rosy apple aphid Dysaphis plantaginea Pass. (Homoptera: Aphididae), a major pest insect on apple trees, was assessed in field experiments in Switzerland, during 1997. In a first experiment, eggs and larvae were released on 3‐year old apple trees infested with five aphids at four different predator‐prey ratios (0:5, 1:5, 1:1, 5:1). In a second experiment, eggs and larvae were released at a predator‐prey ratio of 5:1 on branches of apple trees naturally infested with aphids. In both experiments, the interaction with ants was taken into account and the releases were done at two different times in spring. The results showed that an augmentative release of larvae significantly prevented the build‐up of colonies of D. plantaginea. Significant reductions in aphid numbers were recorded at the two highest predator‐prey ratios, 1:1 and 5:1. Larvae were efficient just before flowering of apple trees at a time when growers normally have to spray their trees. On trees where ants were present the larvae of A. bipunctata were significantly less efficient. Effects of eggs of A. bipunctata, however, were less reliable. At the first date of release (5 April), they did not hatch, probably as a consequence of bad weather conditions.
Life‐history and oviposition behaviour of Amitus bennetti, a parasitoid of Bemisia argentifolii
Authors: Drost Y.C. , Qiu Y.T. , Posthuma‐Doodeman C.J.A.M. , van Lenteren J.C.
Published: October 2003

Amitus bennetti Viggiani & Evans (Hymenoptera: Platygasteridae) is a recently described parasitoid of the silverleaf whitefly, Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae). Behaviour and life history of the parasitoid are described. The first nymphal instar of B. argentifolii is preferred by the parasitoid, but the 1st through 4th instar may be parasitised. Females first investigate hosts with their antennae, then walk over the host, and eventually step with their front legs on the leaf and insert their ovipositor inside the host facing away from the host, while the hind legs are still on the host. The time from encounter to oviposition (=latency to oviposition) is shortest on the 1st instar. Oviposition duration (mean=39 s) comprises 50% of the handling time. Development time from egg to adult decreases from 72 days at 15 °C to 42 days at 20 °C to 28 days at 25 °C. We estimate that 400 degree days is required for development, with a development threshold of 10 °C. Adult longevity in the absence of hosts was 29, 26 and 19 days and with hosts present 8, 8 and 5 days at 15, 20 and 25 °C, respectively. Amitus bennetti is proovigenic and oviposits most eggs shortly after adult emergence. During the first day of their adult lives females laid 1, 31 and 49 eggs at 15, 20 and 25 °C, respectively. Compared with other parasitoid species, the development time of A. bennetti is very long, and the implications of this for management of B. argentifolii are discussed.
Plants with spider‐mite prey attract more predatory mites than clean plants under greenhouse conditions
Authors: Janssen Arne
Published: October 2003

Although many predators and parasitoids are known to respond to odours produced by plants infested with their prey under laboratory conditions, there are actually few studies that show that this response leads to higher numbers of predators or parasitoids on the plants under natural conditions. Here we study the response of predatory mites (Phytoseiulus persimilis Athias‐Henriot, Acari, Phytoseiidae) to odours from cucumber plants infested with two‐spotted spider mites (Tetranychus urticae Koch, Acari, Tetranychidae) in greenhouse release experiments, where predators were released in the centre of a hexagon of cucumber plants. Forty to 57% of all predators released were recaptured on plants within 7 h. Of these, an average of 79.5% were found on infested plants, indicating that these attract about 4 times as many predators as do clean plants. Hence, the blind predatory mites were guided to the plants with prey by herbivore‐induced odours produced by the plant, as was indicated by olfactometer experiments, where it was found that P. persimilis preferred odours from infested cucumber plants to odours from clean cucumber plants. The long‐range searching behaviour of P. persimilis is discussed.
Infochemicals mediating the foraging behaviour of Aleochara bilineata Gyllenhal adults: sources of attractants
Authors: Royer Lucie , Boivin Guy
Published: October 2003

Aleochara bilineata Gyll. (Coleoptera: Staphylinidae) adults feed on eggs and larvae of cabbage maggot, Delia radicum (L.) (Diptera: Anthomyiidae), and might be used to control this pest. We undertook tests in a Y‐tube olfactometer to determine if infochemicals are involved in the food foraging behaviour of A. bilineata adults and to precisely determine the potential sources of stimuli. A. bilineata adults oriented toward the stimuli from both the food‐plant of the prey (rutabaga: Brassica napus var. napobrassica (L.) Reichb.) and the prey‐plant complex (rutabaga infested by cabbage maggot larvae), but adults significantly preferred the effluvia of infested to uninfested rutabaga in a choice test. The sources of infochemicals in the infested rutabaga were the cabbage maggot larvae themselves and their frass. However, in a choice test adults preferred the effluvia of the larvae to that of the damaged rutabaga from which those larvae were obtained. It is not expected that a generalist predator uses precise herbivore‐derived signals in food foraging activity, but the preference of A. bilineata adults for the larval volatiles over frass volatiles may reflect the dependence of this species on dipteran pupae for reproduction.
Effects of selected physical and chemical treatments of Colorado potato beetle eggs on host acceptance and development of the parasitic wasp, Edovum puttleri
Authors: Hu Jing S. , Gelman Dale B. , Bell Robert A.
Published: October 2003

Effects of various physical and chemical treatments of Colorado potato beetle [Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)] eggs on parasitization and development of the egg parasitoid Edovum puttleri (Hymenoptera: Eulophidae) were investigated. UV irradiation did not affect host acceptance but reduced host suitability for UV exposure times ≥90 min. Susceptibility of host eggs to UV irradiation varied with host age; eggs were most vulnerable to damage from irradiation at 12, 18, and 24 h post‐oviposition. The rate of parasitization also was influenced by host age. Percent parasitization was greatest in freshly laid eggs and 24–30 h old eggs. Seventy‐seven percent of host eggs frozen at −20 °C (5 min) were parasitized by E. puttleri, but extended exposure of eggs to −20 °C reduced both acceptance and suitability. Host eggs that had been washed with hexane (removal of kairomone and sticky layer) also were parasitized. After 5 min of washing, application of kairomone significantly increased the rate of parasitism (from 74.7% to 88.2%), but with longer periods of washing, kairomone application had no significant effect on percent parasitism. Thus, the sticky material(s) coating the egg did not appear to be essential for parasitization to occur. Our results provide effective methods and times for treating Colorado potato beetle eggs to maximize parasitization and development of E. puttleri.
Suitability of new and old association hosts for the development of selected microgastrine parasitoids of gramineous stemborers
Authors: Ngi‐Song A.J. , Overholt W.A. , Smith J.W. , Vinson S.B.
Published: October 2003

The present study examined the acceptability and suitability of Old World stemborers (Chilo partellus and C. orichalcociliellus) for the development of New World parasitoids (Apanteles deplanatus and A. minator) and New World stemborers (Diatraea saccharalis and D. grandiosella) for the development of Old World parasitoids (Cotesia sesamiae, C. flavipes and C. chilonis). Results revealed that acceptance and suitability were high in old associations. In new associations, parasitoids accepted about 60% of the new association hosts. In addition, 10 out of 17 new associations were successful. Apanteles species appeared to be more physiologically host specific than Cotesia species. For example, two of four new association hosts were accepted by A. deplanatus and only one (D. saccharalis) was partially suitable for progeny development. Among the Cotesia species, Cotesia flavipes appeared to have a wider host range than the two other species. It attacked all hosts offered and successfully parasitized all but one (D. grandiosella). Diatraea saccharalis was accepted and was a suitable host for the development of all parasitoid species tested, whereas D. grandiosella was unsuitable for the development of four out of five parasitoid species tested. No clear pattern was observed as behavioral acceptance did not always agree with the pattern of physiological suitability. Implications of these findings for importation biological control of stemborers are discussed.
Comparative efficacy of two controlled‐release gypsy moth mating disruption formulations
Authors: Thorpe K.W. , Mastro V.C. , Leonard D.S. , Leonhardt B.A. , McLane W. , Reardon R.C. , Talley S.E.
Published: October 2003

The effects of aerial applications of the gypsy moth sex pheromone, disparlure, on mating disruption and suppression of growth of populations of the gypsy moth, Lymantria dispar (L.), were investigated. Two formulations of disparlure, plastic laminate flakes applied in a single application and polymethacrylate beads applied in two applications, were compared in two separate tests conducted in 1993 and 1994. The beads were applied in two applications spaced 2 weeks apart because preliminary tests had indicated that they released pheromone too rapidly to maintain adequate emission rates throughout the period of male flight. In 1993, the flakes were applied at a rate of 50 g a.i./ha, and the beads were applied at a rate of 15 g a.i./ha for each application. In 1994, the flakes were applied at a rate of 75 g a.i./ha and the beads were applied at rates of 32.5 and 42.5 g a.i./ha for the two applications. Beads with larger average particle size were used in 1994 to prolong disparlure release. The treatments applied in 1993 resulted in >97% reduction in mating and >82% suppression of population growth in the following year. Because of a 1995 collapse of gypsy moth populations in the vicinity of the tests, reliable population growth data were not available for the treatments applied in 1994, but significant mating disruption did occur under both treatments. Based on measurements of residual disparlure after field aging, the flakes released 32 and 48% of their disparlure content during the 6 weeks of male moth flight in 1993 and 1994, respectively. The smaller beads used in 1993 released 75% of their disparlure content, and the larger beads used in 1994 released 52% of their disparlure content, during the 6 weeks of male flight. The biological efficacy data suggest that the bead and flake formulations, as applied in these tests, have similar effects on gypsy moth mating disruption and subsequent population growth. Based on the observed release rates from both 1993 and 1994, a single application of the beads would provide emission rates equal to or greater than those provided by the flakes when applied at an equal dose.
Effects of experimental stress factors on probing behaviour by aphids
Authors: Prado Ernesto , Tjallingii W. Freddy
Published: October 2003

Probing behaviour of Aphis fabae Scopoli and Rhopalosiphum padi (L.) was tested in different stress situations normally occurring in aphid‐plant studies such as interruption of feeding or starvation, transfer to a new plant, and attachment to the electrode wire. The DC electrical penetration graph (EPG) technique and a ‘honeydew clock’ were used to collect data on behavioural effects of these stress conditions. As a general effect, an interruption of feeding behaviour acted as a ‘reset‘, i.e., the same sequence and time course of probing events were shown, irrespective the interruptions duration, from 1–100 min. Nevertheless, some minor differences were found, especially in A. fabae. Increased interruption times (deprivation from the host plant) stimulated the aphids to insert their stylets earlier. When A. fabae was put back on its host plant after a one min interruption phloem feeding started earlier than with longer interruption times, but only when it was put back to the same plant and feeding site on which it fed before. It is concluded that this effect is at least partly due to ‘memory’ of previous probing/feeding experience on the plant as it vanishes with longer interruption times. This explanation also holds for phloem salivation (E1) before starting sustained sap ingestion, which was reduced on the previous feeding site, but only after the one min interruption in A. fabae. The aphid‐plant specificity appeared high in these effects. Both aphids were somewhat affected by wiring, resulting in earlier probing, longer total pathway phase, and less and later phloem feeding (as reflected by honeydew excretion). Thus confirming, that the evaluation of EPG results can be improved with supplementary data from free aphids.
Isolation of insecticidal lectin‐enriched extracts from African yam bean (Sphenostylis stenocarpa) and other legume species
Authors: Omitogun O.G. , Jackai L.E.N. , Thottappilly G.
Published: October 2003

Insecticidal lectins were isolated from 20 resistant Vigna and non‐Vigna legumes and tested againstn 3 pests of cowpea namely: Maruca vitrata, Callosobruchus maculatus and Clavigralla tomentosicollis. Crude lectins were separated from seeds using sodium chloride extraction, ammonium sulfate fractionation, and dialysis. SDS‐PAGE indicated the molecular size of ca. 30 kDa for the most intense (and presumably active) band. Haemagglutination assays using trypsin‐treated rabbit erythrocytes suggested that lectins were among the extracted proteins. Extracts from Lablab purpureus and Sphenostylis stenocarpa both non‐Vigna spp., caused greater agglutination than those from the wild Vigna species. Bioassays on all three insect species using the lectin extracts incorporated in either artificial cowpea seeds (5% w/w) or in modified Vanderzant legume pod borer diet (1% w/v) indicated that the non‐Vigna extracts were highly toxic to the insects. Mortality after 10 days was >80% in the most toxic extracts. The extract from one of the accessions of Sphenostylis stenocarpa, an edible legume, was singled out for lectin purification and future gene cloning with the view of using it for engineering resistance to cowpea pests.
Factors influencing dispersal of larval Coleomegilla maculata from the weed Acalypha ostryaefolia to sweet corn
Authors: Cottrell Ted E. , Yeargan Kenneth V.
Published: October 2003

The polyphagous predator, Coleomegilla maculata (DeGeer) (Coleoptera: Coccinellidae), commonly oviposits on the native weed, Acalypha ostryaefolia Riddell (Euphorbiaceae), in and around Kentucky sweet corn fields. Cannibalism of eggs by C. maculata adults and larvae is drastically lower on A. ostryaefolia than on nearby sweet corn plants. We examined ovipositional preference of C. maculata for A. ostryaefolia plants or sweet corn plants, dispersal of larvae from A. ostryaefolia plants, capability for dispersal of larvae across bare soil (e.g., to nearby plants), ability of larvae to climb from ground level up A. ostryaefolia plants or sweet corn plants, and effect of A. ostryaefolia borders adjacent to sweet corn plots on C. maculata population density in sweet corn. The ovipositional preference study revealed that C. maculata laid more eggs on A. ostryaefolia than on corn. First‐instar C. maculata that hatched from egg clusters on A. ostryaefolia dispersed predominantly by falling, rather than crawling, to the ground. Glandular trichomes on A. ostryaefolia petioles and stems apparently inhibited intraplant movement of first instars, resulting in those larvae falling directly from leaves to the ground. Some first instars were capable of moving at least 8 m across bare soil in 24 h. From the ground, significantly more first instars climbed sweet corn plants than climbed A. ostryaefolia plants. Significantly more larvae were present in sweet corn plots bordered by A. ostryaefolia plants than in sweet corn plots without an A. ostryaefolia border. These findings show that physical attributes of companion plants can significantly influence natural enemy populations on crop plants by affecting interplant dispersal of natural enemies.
Chemo‐discriminatory neurones in the sub‐oesophageal ganglion of Locusta migratoria
Authors: Rogers Stephen M. , Simpson Stephen J.
Published: October 2003

The sub‐oesophageal ganglion of Locusta migratoria was searched for neurones responsive to stimulation of the maxillary palps using intracellular recording techniques. Two plant stimuli were used: wheat, a host plant and cabbage, an unacceptable non‐host plant. The stimuli were presented to the palp as both intact leaf tissue and as droplets of aqueous solutions of plant extracts. All the sampled neurones that responded to stimulation of the palp also responded to simple mechanical stimulation. However, 25% of the neurones exhibited consistent differences in response to the two plants when presented as both leaf tissue and droplets, strongly suggesting that they also received a chemosensory input. These differential responses most commonly took the form of differences in the duration of cell activity and/or variation in the latency of the onset of response. The receptive fields of differentially responding neurones were confined to the maxillary palp, or at most to the maxillary and labial palps.
Specialist deterrent chemoreceptors enable Pieris caterpillars to discriminate between chemically different deterrents
Authors: van Loon Joop J.A. , Schoonhoven Louis M.
Published: October 2003

Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so‐called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 μM). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide‐treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.
Integrating nutrition: a geometrical approach
Authors: Raubenheimer D. , Simpson S.J.
Published: October 2003

We present and illustrate using data from insects an integrative approach to modelling animal nutrition. This framework enables the unification within simple geometrical models of several nutritionally relevant measures. These include: the optimal balance and amounts of nutrients required to be ingested and allocated to growth by an animal over a given time period (the intake and growth targets, respectively); the animal's current state in relation to these requirements; available foods and the consequences for the animal's state of ingesting them; the amounts of ingested nutrients that are retained and eliminated; and animal performance. Data are presented on intake targets in insects, illustrating how they change over various time‐scales (physiological, developmental, and evolutionary). Most importantly, the geometrical approach enables a clear description to be made of the trade‐offs reached by animals in regulating their nutritional balance. Animals given a nutritionally balanced food, or two or more imbalanced but complementary foods, can satisfy their nutrient requirements. However, those eating non‐complementary imbalanced foods must reach a suitable compromise between over‐ingesting some nutrients and under‐ingesting others. Data are presented comparing the rules of compromise for protein and carbohydrate ingestion in grass‐feeding (Locusta migratoria) and polyphagous (Schistocerca gregaria) locusts.
Absence of food‐aversion learning by a polyphagous scarab, Popillia japonica, following intoxication by geranium, Pelargonium × hortorum
Authors: Potter Daniel A. , Held David W.
Published: October 2003

It is commonly held that food‐aversion learning should be more prevalent in polyphagous herbivores than in specialists. We tested the ability of Popillia japonica, a polyphagous scarab, to learn avoidance of a palatable but illness‐inducing plant. Beetles that feed on flowers of geranium, Pelargonium × hortorum, became paralyzed, although most recovered within 24 h. In choice tests, naive beetles strongly preferred geranium petals over leaves of linden, Tilia cordata, a highly suitable host. Experienced beetles maintained this preference although it resulted in repeated bouts of paralysis. Fecundity was >10 times higher for beetles fed linden foliage for 2 wk than for those fed only geranium. Nevertheless, when a surplus of both foods was provided, the beetles fed mainly on geranium, resulting in greatly reduced fecundity. These results contradict the view that generalists should show propensity for food‐aversion learning. Indeed, in this case, P. japonica continued to prefer the toxic plant, compromising its fitness.
Examining the hierarchy threshold model in a no‐choice feeding assay
Authors: Withers Toni M.
Published: October 2003

The hierarchy threshold model of individual insect diet predicts the acceptance or rejection of individual hosts when encountered by insects. One assumption of the hierarchy threshold model is that ‘post‐discrimination phase’ insects which accept lower ranked hosts will also accept hosts that are ranked higher. This assumption does not however suggest whether or not such insects behave differently when encountering these two hosts. This question is explored using Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae). Adult beetles that had just fed, or were one inter‐meal interval after feeding, or were deprived for three or six days after feeding, were individually observed on a plant that either ranked high, Parthenium hysterophorus L., or low Xanthium occidentale Bertol. (Heliantheae: Ambrosiinae) in choice tests. Just‐fed beetles were generally unresponsive to either host plant and did not feed. Beetles held for one inter‐meal interval showed more feeding responses (shorter lag time between sampling and feeding, higher proportions of individuals feeding, and more time feeding) towards the higher ranked plant. As the beetles approached six days deprivation, behaviours of sampling, feeding and locomotion differed less between the two plants, but were still apparent. I conclude that food deprived Z. bicolorata beetles do still discriminate between the two plants. This result partially supports the hierarchy threshold model.