bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of prey infected by nuclear polyhedrosis virus on a predator, Sycanus leucomesus Walk. (Hem., Reduviidae)
Authors: Sajap A. S. , Kotulai J. R. , Kadir H. A. , Hussein M. Y.
Published: March 2003

Abstract: An assassin bug, Sycanus leucomesus Walk. (Hem., Reduviidae) fed on nuclear polyhedrosis virus (NPV)‐infected larvae of Spodoptera litura Fabr. (Lep., Noctuidae) inflicted variable effect on its developmental biology. The impact varied with the duration the predators were exposed. The predators that were fed infected prey throughout their lives appeared normal but they had significantly smaller sizes of head capsules and shorter tibial lengths than those fed healthy prey. These individuals had their overall pre‐imaginal survival rate reduced by 10% from 91.25 to 81.25%, pre‐oviposition period prolonged to more than 12 days, longevity reduced by 10 and 19 days in the males and females, respectively, and fecundity reduced to 41%. Even though ingestion of NPV could adversely influence their biology, the predators could serve as disseminators of the pathogen. The predators defecated infective viral polyhedral inclusion bodies (PIBs) ranging from 1.22 to 1.60 × 1010/deposit with an average of 1.42 × 1010. This NPV, when fed to its original host, caused 97% larval mortality within 10 days. Thus in nature, S. leucomesus may suppress the pest population not only by predation but also by dispersing the pathogen.
Virulence of nucleopolyhedroviruses from Orgyia pseudotsugata and Orgyia leucostigma (Lep., Lymantriidae) for early instars of the white‐spotted tussock moth, Orgyia thyellina
Authors: Walsh P. J. , Glare T. R. , Nelson T. L. , Sadler T. J. , Ward V. K.
Published: March 2003

The white‐spotted tussock moth, Orgyia thyellina, was found in Auckland, New Zealand, in 1995. An eradication campaign against this potential pest is currently underway, but in the event that it is unsuccessful, agents for population suppression will be required. As no pathogens were available from O. thyellina, two nucleopolyhedroviruses (NPVs) from Orgyia pseudotsugara (OpMNPV ‘VirtussTM’) and Orgyia leucostigma (OrleSNPV) were imported from Canada and tested for virulence against O. thyellina. At 105 polyhedral inclusion bodies per cm2 and above, 100% mortality was achieved with first to second instar larvae by 15 days. Molecular comparison of sequences from the pol gene region of each virus demonstrated that they were from different genotypic groups of NPVs.
The side‐effects of plant extracts and metabolites of Reynoutria sachalinensis (F. Schmidt) Nakai and conventional fungicides on the beneficial organism Trichogramma cacoeciae Marchal (Hym., Trichogrammatidae)
Authors: Hafez M. B. , Schmitt A. , Hassan S. A.
Published: March 2003

The aim of this study was to investigate the side‐effects of plant extracts (plant strengthener with resistance inducing properties) and conventional fungicides on the egg parasitoid Trichogramma cacoeciae Marchal. Two plant extracts and one metabolite from Reynoutria sachalinensis (F. Schmidt) Nakai (crude water extract (Rey‐crude®), which is used for the control of powdery mildew and other diseases, a methanolic fraction of this extract (Rey‐meth®) and the anthraquinone plant constituent (Physcion®), as well as four fungicides (Thiram®, Dithane® M45, Euparen M® and Kumulus®) were tested. Adults of T. cacoeciae of uniform age were exposed to fresh dry film of the compounds and the percentage reduction in parasitism compared with water‐treated controls was calculated. The results of experiments using the highest recommended concentrations sprayed on glass plates showed that the preparations greatly differed in their effect on the parasitoid. All of the conventional fungicides tested were found to be harmful. In contrast, Rey‐crude and Physcion were harmless to T. cacoeciae, whereas the fraction Rey‐meth was slightly harmful. In further experiments the side‐effects of the plant protection agents on T. cacoeciae were compared when sprayed at different concentrations either on glass plates or on vine leaves. The results confirmed the findings of the first trials but showed that side‐effects of the compounds Dithane M45 and Euparen M were less toxic when applied to vine leaves.
Toxic effects of Canavalia ensiformis L. (Leguminosae) on laboratory colonies of Atta sexdens L. (Hym., Formicidae)
Authors: Hebling M. J. A. , Bueno O. C. , Pagnocca F. C. , Da Silva O. A. , Maroti P. S.
Published: March 2003

Laboratory colonies of the leaf‐cutting ants Atta sexdens that were fed daily with leaves of Canavalia ensiformis showed a high ant mortality, and a significant decrease in fungal garden volume, with complete depletion of nests after 11 weeks of treatment.
Genetic population structure in olive fly Bactrocera oleae (Gmelin): gene flow and patterns of geographic differentiation
Authors: Ochando M. D. , Reyes A.
Published: March 2003

Four wild Spanish populations of Bactrocera oleae (Gmelin) (Dipt., Tephritidae) were studied by gel electrophoresis, in order to find out their population genetic structure and the relative importance of gene flow in that structure. A great amount of genetic variability was observed. In terms of the pattern of the genetic variability in our populations, the most noticeable characteristics were the similarity of the configuration of allelic frequencies from locality to locality, the existence of exceptions and quantitative differences within that similarity, and the heterogeneity among the variable loci. Gene flow estimated from Wright's method gave a value of Nm = 8.9. However, the FST statistic in three of the loci ranged from 0.0451 to 0.0620 indicating a substantial degree of differentiation among populations (P < 0.001). The present observations seem to support the hypothesis that although gene flow could be high (Nm = 8.9), ‘natural’ selection, probably due to agricultural practices, may be the major factor responsible for the pattern of the genetic variability observed in B. oleae.
Ant predation of larval Diatraea saccharalis Fab. (Lep., Crambidae) in new sugarcane in Brazil
Authors: Rossi M. N. , Fowler H. G.
Published: March 2003

Abstract: Ant predation of natural field populations of larval sugarcane borers, Diatraea saccharalis, was evaluated by using insecticidal check techniques, and through survivorship studies of artificial high‐density infestations, in plantations in Brazil. Areas of ant suppression had higher levels of D. saccharalis than unsuppressed areas, although both types of areas normally had extremely low D. saccharalis populations. Artifical infestations of D. saccharalis yielded significantly lower larval survivorship in unsuppressed areas than in suppressed areas. Fire ants (Solenopsis spp.) were always the most abundant ant. This study has demonstrated that ants are important pest predators in Brazilian sugarcane fields.
Fertility life table of Trichogramma pretiosum (Hym., Trichogrammatidae) in eggs of Tuta absoluta and Phthorimaea operculella (Lep., Gelechiidae) at different temperatures
Authors: Pratissoli D. , Parra J. R. P.
Published: March 2003

Abstract: The aim of this work was to study the reproductive potential of Trichogramma pretiosum reared on Tuta absoluta and Phthorimaea operculella eggs through fertility life tables at different temperatures. The development cycle and the parasitization capacity of this parasitoid was determined in order to calculate the net reproductive rate (Ro), the infinitesimal increase ratio (rm), the finite increase rate (λ) and the mean duration of the generation (T). The mean duration of one generation of T. pretiosum kept on both eggs was observed to show an inverse relation with the increase of temperature. The net reproduction rate varied according to the temperature variation for both species. The maximum increase in capacity of T. pretiosum on the first host (T. absoluta) was reached at 22°C and on the second host (P. operculella) between 22 and 25°C. The infinitesimal increase rate and the finite increase rate for both moths had a relationship with the increase of temperature ranging from 18 to 30°C. The highest value of λ for both moths occurred at 30 and 32°C according to the lesser duration of a generation.
Control of summer and winter diapause in the leaf‐mining fly Pegomyia bicolor Wiedemann (Dipt., Anthomyiidae)
Authors: Xue  , Zhu  , Shao
Published: March 2003

Effects of photoperiod and temperature on diapause induction and termination were investigated in both aestival and hibernal pupae of Pegomyia bicolor Wiedemann under field and laboratory conditions. In the field, summer diapause had occurred already in part of the first pupal population; the proportion of diapause gradually rose as the day length and temperature increased. This fly is a short‐day species with a pupal summer and winter diapause. Summer diapause was induced by both long day‐lengths and mild temperatures. The whole larval life is sensitive to photoperiod. Winter diapause was induced mainly by low temperatures, especially in the first 10 days after pupation. High temperatures strongly enhanced summer diapause induction regardless of photoperiod. The diapause‐averting influence of short photoperiods was fully expressed only at moderately low temperatures. High temperatures delayed diapause development, resulting in a rather long summer diapause; whereas low temperatures hastened it, leading to a short winter diapause and showing a low thermal threshold for diapause development. In the field, the post‐diapause development started in January, the coldest month, suggesting that the thermal requirements for post‐diapause development is also low.
Within‐patch search flights by Pachyneuron aphidis (Hym., Pteromalidae): a potential strategy to compensate reduced foraging speed by foot
Authors: Hübner G.
Published: March 2003

Search flights of the aphid hyperparasitoid Pachyneuron aphidis were observed under field conditions. The pattern and duration differed from those described for aphid primary parasitoids. Forty per cent targeted landings close to aphid colonies indicate that P. aphidis females locate potential host sites during slow and extraordinary long flights in the host plant Cirsium arvense. A comparison between different aphid hyperparasitoids showed that the walking speed of P. aphidis was significantly slower than that of other polyphagous species. This suggests that search flights were performed in order to compensate for a reduced efficiency of foraging on foot.
Size of orchard trees as a factor affecting behavioural control of apple maggot flies (Dipt., Tephritidae) by traps
Authors: Prokopy R. J. , Wright S. E. , Black J. L. , Rull J.
Published: March 2003

Over a 3‐year period (1997–1999), we examined the influence of tree size on effectiveness of traps for behaviourally controlling apple maggot flies, Rhagoletis pomonella (Walsh), in small blocks of trees in Massachusetts commercial apple orchards. Traps were red spheres coated with Tangletrap and baited with an attractive synthetic host fruit odour (butyl hexanoate). Traps were placed 6 m apart on perimeter apple trees of each block and were designed to intercept apple maggot flies immigrating into blocks from unmanaged host trees. Based on captures of adults by unbaited red spheres placed near the centre of each block to monitor degree of adult penetration into the interior and on percentages of fruit injured by apple maggot, traps surrounding blocks of small trees (1.5 m canopy diameter) planted at high density were more effective in controlling apple maggot flies (relative to control obtained by insecticide sprays used in comparison blocks) than were traps surrounding blocks of large trees (3.7 m canopy diameter) planted at low density, with traps surrounding blocks of medium‐size trees (2.5 m canopy diameter) planted at medium density generally providing an intermediate level of control.
Flight activity of predatory Staphylinidae in agriculture in central Germany
Authors: Markgraf A. , Basedow T.
Published: March 2003

The flight activity of predatory staphylinids was studied at two sites of Bad Vilbel near Frankfurt/M. (Germany) by window traps on the borders between fields of sugar beet and cereals, in 1989–1991, and by one light trap in 1989. Although Paederus litoralis and Paederus riparius were not observed flying, 84 other staphylinid species were, of which 26 were also observed on the soil of the fields. The flight intensity was very high in Oxytelus and Tachyporus spp., with the flight showing a peak early in the season and sometimes an additional one in the autumn. The flight activity was compared with the average population density. No correlation was found between population density in the fields and flight activity for the 26 agricultural species.
A simple and rapid technique for assaying toxicants in aphids
Authors: Xenou‐Kokoletsi M. , Christias C.
Published: March 2003

A simple bioassay technique has been developed in order to study the effect of toxic compounds on aphids. The technique involves dipping of leaves of a particular aphid host in a solution of the desired toxic compound contained in a vacuum flask. The flask is then connected to a vacuum source in order to remove the air from the intercellular spaces of the palisade and the spongy parenchymas of the leaves. Breakage of the vacuum and return to atmospheric pressure forces the test solution into the now empty intercellular spaces which are thus filled with the solution. The treated leaves exhibited a typical water‐soaked appearance. The infiltrated leaves were then offered to the aphids. The above treatment did not affect either the structure of the leaves or the development of the aphid colony on them. Aphids grown on leaves infiltrated with water lived longer in comparison with controls. In addition, insects grown on leaves infiltrated with 27.5, 13.7 and 6.9 p.p.m. of the systemic insecticide heptenophos died after 1.5, 3.0 and 5.0 h, respectively. The bioassay technique described in this report has certain advantages: it is simple, fast and inexpensive and is especially suitable for short‐term studies involving the effects of such chemicals as toxins, insecticides and other toxicants on aphids. It may also be used to study the effects of growth factors, hormones and special nutrients on aphid growth and possibly on other sucking insects.
The influence of mixed aphid diets on larval performance of Coccinella septempunctata (Col., Coccinellidae)
Authors: Nielsen F. H. , Hauge M. S. , Toft S.
Published: March 2003

Abstract:  Three questions regarding possible benefits of mixed diets for the specialist aphid predator, Coccinella septempunctata larvae were investigated. (1) Do aphids species from different host plants complement each other nutritionally? (2) Is a mixed diet of high‐quality aphids beneficial? (3) How does the quality of mixed diets depend on the quality of constituent species? All mix‐combinations of aphid species of high (Metopolophium dirhodum), intermediate (Myzus persicae), and poor food quality (Aphis sambuci), and the three single‐species diets were compared. A mixed diet of two high‐quality species (Sitobion avenae and M. dirhodum) was also compared with single‐species diets. Larvae that were given pure A. sambuci and a mixed diet of A. sambuci + M. persicae died within 18 days and none of the larvae developed to fourth instar. Metopolophium dirhodum was generally of higher quality as food than M. persicae, whereas the mixed diet of M. dirhodum + M. persicae was intermediate. Sitobion avenae and M. dirhodum were found to have approximately the same food value. Coccinella septempunctatam larvae that were offered a mixed diet of these two high‐quality aphids gained no extra advantage. Overall, no benefit from mixing of aphid species was found. The quality of mixed diets depended on the quality of the constituent species.
Effects of isolation and crowding on the haemolymph pigment composition of the desert locust, Schistocerca gregaria (Orth., Acrididae)
Authors: Deng A. L.
Published: March 2003

Abstract:  An experimental study on the effect of isolation and crowding of the desert locust, Schistocerca gregaria (Forskål) on haemolymph pigment composition (as measured by absorbance ratios at 460 and 680 nm) was carried out at the International Centre of Insect Physiology and Ecology, Nairobi. The results showed that haemolymph absorbance ratios of gregarious and solitarious locusts were different (P < 0.05) and that there was no phase‐specific sex differentiation with regard to this measure (P < 0.05). The haemolymph pigment composition changes during isolation and grouping showed contrasting trends. It changed rapidly in nymphs, but slowly and erratically in adults both resulting from isolation and grouping at hopper stage. Significant shifts in locust phase status were recorded in both situations in nymphs in F0 generation, and in the adults by the end of the F2 and F3 generations of solitary and gregarious conditions, respectively. Shifting of fledglings did not induce significant changes in their mean absorbance ratios in both situations, i.e. isolation and crowding within F0 generation. The ratio of length of posterior femur (F) to greatest width of the head capsule (C) changed either at a similar rate or more often slower than the haemolymph pigment ratio and both required more than a generation to transform fully. The study has shown that haemolymph pigment composition could be a suitable measure for monitoring phase changes at nymphal stages of the desert locust.
Age‐specific survival and fecundity and their effects on the intrinsic rate of increase of Aphelinus gossypii (Hym., Aphelinidae), a parasitoid of Aphis gossypii (Hom., Aphididae)
Authors: Perng Jen Jiun , Liu Yu Chang
Published: March 2003

Abstract: The age‐specific survival and fecundity of female adults of the aphidophagous parasitoid, Aphelinus gossypii Timberlake (Hym., Aphelinidae), were determined at a host density of 50 Aphis gossypii Glover (Hom., Aphididae) per leaf of Ageratum houstonianum Mill each day at 25°C. The age‐specific mummy production, emergence rate and sex ratio of progeny were calculated. The implication of these results in terms of potential population growth of A. gossypii and related species is discussed. The age‐specific survival curve (lx) of females exhibited a Type I pattern, which resulted in little difference between Σmx and Σlx mx. The lx curve of males exhibited a Type II pattern, and their survival time was much shorter than that of females. Each mated female produced on average 598.9 ± 64.0 aphid mummies, and preyed on 87.9±6.2 aphids. Most of the biological performance parameters were not different significantly between mated and virgin females. The highly female‐biased sex ratio of offspring produced by mated females soon after their emergence resulted in a high fecundity rate (mx) during the early reproductive period. Therefore, although the sex ratio of progeny was male‐biased during the entire reproductive period, the intrinsic rate of increase estimated using age‐specific sex ratios was larger than that estimated using a constant sex ratio of 0.5. These results indicate that the high survival and the adaptation of producing mostly female offspring during the early reproductive period contribute much to the population increase potential of this parasitoid.
Field trials with Imidacloprid (Confidor) on the Italian locust Calliptamus italicus in Kazakhstan
Authors: Wilps H. , Levchenko V. , Vernigor A.
Published: March 2003

Abstract: The Italian locust Calliptamus italicus is the most common and dangerous pest species of nearly the whole of Kazakhstan and neighbouring countries. This univoltine locust can aggregate and its hopper bands and adult swarms invade agricultural areas regularly and frequently cause significant damage to wheat, sunflowers, beans, etc. In the trials presented, two different Confidor formulations, namely Confidor 200 SL and 010 UL were tested on C. italicus hopper bands in Kazakhstan. The former formulation was tested twice – the mortality rates reached nearly 90% at the remarkably low dosage of 7.5 g a.i./ha. The ULV formulation 010 UL sprayed with 10 g a.i./ha caused about 75% mortality in 2 to 3 days. Preliminary observations did not show any impact on the non‐target organisms but further ecotoxicological field data are required.
In vivo production of recombinant protein by a baculovirus vector inoculated perorally to the prefinal instar larvae of Bombyx mori L. (Lep., Bombycidae) aided by an optical brightener, Tinopal UNPA‐GX
Authors: Arakawa T. , Kozuma K.
Published: March 2003

Abstract: Budded particles of nucleopolyhedrovirus (NPV) were found to infect perorally the 4th (prefinal) instar larvae of Bombyx mori L. that were treated by an optical brightener, Tinopal UNPA‐GX (Tinopal). Host larvae were fed a diet containing 0.3% (w/w) Tinopal on day 1 in the 4th instar and then fed a diet contaminated by budded particles of NPV (1.0 × 106 TCID50 U/larva) that was pathogenic to B. mori (BmNPV) on day 2 (inoculation schedule 1). Another set of host larvae was fed a diet containing BmNPV budded particles (2.5 × 106 TCID50 U/larva) together with 0.3% (w/w) Tinopal on day 1 in the 4th instar (inoculation schedule 2). Host larvae treated by both schedules died of viral infection. The operation of schedule 2 is simpler than that of schedule 1, although the former required higher doses of the virus for satisfactory infection. We inoculated a baculovirus vector carrying human serum albumin (HSA) gene into 4th instar B. mori larvae by schedule 1. Recombinant HSA was detected in the homogenate of host larvae 4 days after inoculation. The peroral inoculation of BmNPV budded particles aided by Tinopal may thus lead to industrial pharmaceutical production using a baculovirus vector for large numbers of insect hosts.
Response of arthropods associated with the canopy of common beans subjected to imidacloprid spraying
Authors: Marquini F. , Guedes R. N. C. , Picanço M. C. , Regazzi A. J.
Published: March 2003

Abstract:  Imidacloprid, the first neonicotinoid of potential use in agriculture, became an important agent for controlling leafhoppers, aphids, thrips and whiteflies. The use of this compound was extended to common beans in Brazil, a crop of great socio‐economic value throughout Latin America, and the aim of the present work was to assess the temporal effectiveness and environmental safety of this insecticide to the arthropod community associated with the canopy of this crop plant. Thirty six species of phytophagous and detritivorous species were collected, as well as 37 species of predators and parasitoids. However, there was no significant impact of imidacloprid on species richness. In contrast, the insecticide significantly decrease the arthropod abundance for over a 30‐day period. This impact is probably a reflection of the effect of this insecticide on Thrips tabaci and Caliothrips brasiliensis (Thysan., Thripidae) the most frequent and abundant species present in the area, and important pests of common beans in Brazil. Among the other most frequent taxa (present in over 50% of the samples), Araneae (predators) and the green leafhopper Empoasca kraemeri (Hom., Cicadellidae), another important bean pest in Brazil, were not significantly affected by imidacloprid, unlike the thrips species T. babaci and C. brasiliensis which showed decreased population levels until 8 days after imidacloprid application.
Regulation of in vitro Ptr‐toxin Production by Pyrenophora tritici‐repentis Isolates by Environmental Parameters and Accumulation of Ptr‐toxin in Culture over Time
Authors: Brown D. A. , Hunger R. M.
Published: March 2003

Previous work has demonstrated the production of a low molecular weight toxin (designated Ptr‐toxin) by isolates of Pyrenophora tritici‐repentis (Died.) Drechs., the cause of tan spot of wheat (Triticum aestivum). Before the mechanisms by which Ptr‐toxin is produced are understood, conditions for optimal toxin production must be identified. This study defined glucose concentration, light and temperature for optimal fungal growth and accumulation of Ptr‐toxin in a defined mineral salts‐glucose liquid medium. The accumulation of Ptr‐toxin in culture was monitored over a 21‐day period. The growth of six P. tritici‐repentis isolates increased significantly over the range of 0.05–5.0% glucose; however, the greatest accumulation of Ptr‐toxin was observed at 1 and 2% glucose. Significant increases in fungal dry weights were observed at 23 and 30°C, although the effect of temperature on toxin production remains questionable. No significant influence of light on growth and Ptr‐toxin production was observed. Ptr‐toxin continues to accumulate in culture over the 21‐day period tested in this study. The results of the present study reveal much about the specific isolates included but little information upon which generalizations may be based. As such, screening numerous P. tritici‐repentis isolates for Ptr‐toxin production under one set of conditions appears to be unreliable.
Accumulation of a Metallothionein‐like mRNA in Norway Spruce Under Environmental Stress
Authors: Etscheid M. , Klümper S. , Riesner D.
Published: March 2003

Differential screening of a Norway spruce (Picea abies L., Karst) cDNA library with probes from damaged and symptomless trees identified a cDNA clone of a 650 nt metallothionein‐like (MTL) mRNA as damage‐related. Northern blot analysis revealed an about six‐fold increase of the MTL mRNA in damaged trees in 1 year and a two‐fold increase in the consecutive year. In the N‐terminal domain this MTL mRNA comprises typical CysXCys motifs of a subgroup of class II MTL proteins found in kiwi and a few other plant species. In the C‐terminal domain, however, the Norway spruce MTL protein is different to the kiwi subgroup and also distinct from a novel Douglas fir metallothionein‐related protein, respectively. Hence, the cDNA identified during this study may represent a new type of MTL protein in plants. The accumulation of this MTL mRNA in needles of trees growing in an area of high ozone, sulphur dioxide and nitrogen oxide input and showing clear symptoms of forest decline may be a senescence effect or may play a role in the metal‐mediated regulation of the intracellular activated oxygen concentration.
Activity of Fluazinam against Strains of Botrytis cinerea Resistant to Benzimidazoles and/or Dicarboximides and to a Benzimidazole‐phenylcarbamate Mixture
Authors: Kalamarakis A. E. , Petsikos‐Panagiotarou N. , Mavroidis B. , Ziogas B. N.
Published: March 2003

Fluazinam is a new active ingredient for the control of grey mould, belonging to the novel broad spectum phenylpyridinamine fungicides. The effect of fluazinam was studied on one wild type and four strains of Botrytis cinerea, which had been isolated from vegetable crops in Greece, and were resistant to benzimidazoles and/or dicarboximides and to the mixture of benzimidazoles (carbendazim) + phenylcarbamates (diethofencarb). In vitro fluazinam was found to be highly active against strains of B. cinerea which were sensitive or resistant to benzimidazoles or exhibited multiple resistance to benzimidazoles, dicarboximides and to the mixture carbendazim + diethofencarb [EC50 and EC95 values (concentration of active ingredient that suppresses mycelial growth to 50 and 95%, respectively, of that of the fungus on fungicide‐free agar medium) calculated with probit analysis, ranged from 0.044 to 0.069 and 0.58 to 1.6 μg/ml, respectively]. No cross‐resistance was observed between fluazinam and the market products benomyl, iprodione or carbendazim + diethofencarb. Preventive applications of fluazinam in vivo completely inhibited infections of cucumber seedlings by all the above‐mentioned resistant strains of B. cinerea. Benomyl and iprodione did not effectively control the benzimidazole‐ and dicarboximide‐resistant strains. The mixture of carbendazim + diethofencarb insufficiently controlled the strain of B. cinerea with moderate resistance to benzimidazoles. The results of this investigation indicate that it should be possible to use fluazinam as an alternative in resistance management programmes against grey mould.
Preliminary Observations on Resistance to Rust Diseases of Kentucky Bluegrass Ecotypes from Poland
Authors: Czembor E. , Feuerstein U. , Żurek G.
Published: March 2003

Four hundred and forty‐four ecotypes of Kentucky bluegrass (Poa pratensis L.) collected from Poland were screened for rust resistance. A field experiment was established at Hof Steimke, DSV (Deutschen Saatveredelung), Germany. The ecotypes originated from the Polish Gene Bank, IHAR – Botanical Garden, Bydgoszcz. Sixty‐two (13.9%) ecotypes that scored on average more than 5 were included in a group with high resistance. Ecotypes scored on average less than 5 were either included in a susceptible group (average scores 4.0–4.9) or a very susceptible group (average scores 2.0–3.9). There were 181 ecotypes in the susceptible group (40.8%) and 201 (45.3%) in the very susceptible group. Thirty‐three (7.4%) ecotypes were more resistant and 29 (6.5%) ecotypes had resistance on the level of the most resistant control variety Ottos (score of resistance 5.3). Eight ecotypes (1.8%) with the highest level of resistance (score 7 or higher) were identified as especially promising sources of rust resistance. One ecotype (141858) showed reaction type 9 in both years and another one (141903) showed reaction type 9 in one year and reaction type 8 in another year (mean 8.5). Six ecotypes were scored on average 7 or 7.5. For 17 different habitats from which the tested ecotypes were collected only those ecotypes originating from 10 habitats (meadow, peat meadow, forest meadow, pasture, field, lakeside, waterside, ditch, roadside and gravel pit) showed high levels of resistance to rust. The value of newly identified resistant ecotypes for control of rusts on Kentucky bluegrass is discussed.
A Method for the Artificial Inoculation of Potato Tubers with Phytophthora infestans and Polymerase Chain Reaction Assay of Latently Infected Sprouts and Stems
Authors: Appel  , Adler  , Habermeyer
Published: March 2003

This article contains a detailed description of a reliable method for the inoculation of potato tubers with Phytophthora infestans. This technique was developed as a general basic method for greenhouse and field trials to study the development of the primary inoculum source in potato crops. It was applied to increase the reproducibility of infections from tubers to sprouts. Afterwards the pathogen was detected in light sprouts and stems at different stadiums of plant growth by the polymerase chain reaction‐based test (PCR). From this it follows that Phytophthora infestans is able to grow directly up into the stem from the tuber as mycelium. In the course of plant growth the concentration of mycelium fell below the detection limit in some of the assayed stems on account of dilution effects, although the symptoms occurred in the following period. Apparently the pathogen is also able to cause symptoms in the plant at very low concentrations.
Epidemiology of Phytoplasma Diseases in Papaya in Northern Australia
Authors: Padovan A. C. , Gibb K. S.
Published: March 2003

Using molecular tools, the spread of phytoplasma diseases in a papaya plantation was investigated for 3 years to identify phytoplasma strains affecting papaya, insect vectors and alternative plant hosts. Five phytoplasma strains (SPLL‐V4, TBB, CaWB, StLL and WaLLvar) were associated with papaya yellow crinkle disease and one phytoplasma strain (PDB) was associated with papaya dieback disease. The most prevalent strains were TBB and SPLL‐V4 which occurred in 94% of infected papaya. There was a significant correlation between phyllody and TBB, and virescence and SPLL‐V4, although other phytoplasma types could also be associated with either phyllody or virescence. No mixed infections were detected in diseased papaya. Disease progress curves for TBB and SPLL‐V4 showed a sigmoid response reaching a maximum disease incidence of 16% after 24 months. The rate of disease spread was best described by a logistic model which showed that TBB spread at a slightly higher rate than SPLL‐V4. Ten phytoplasma strains were detected in 14 alternative plant species; however, TBB and SPLL‐V4 were present in only a few individual plants of some of these species, so these alternative hosts would probably not have provided a significant infection source to papaya. Very few phytoplasmas were detected in leafhoppers collected over 3 years with TBB and SPLL‐V4 only detected in Orosius spp.
Fungal Communities and Disease Symptoms on Stem Bases of Wheat and Barley and Effects of Seed Treatments Containing Fluquinconazole and Prochloraz
Authors: Dawson W. A. J. M. , Bateman G. L.
Published: March 2003

Three successive crops of winter wheat or barley were grown as second, third and fourth cereals. Communities of fungi on shoot bases, identified after isolation on agar media, were more diverse (determined by number of taxa identified) on wheat than on barley, and their diversity increased from year to year. Diversity was not affected by seed treatments containing fluquinconazole or prochloraz. Eyespot (caused by Tapesia spp.) and brown foot rot (caused by Fusarium spp. or Microdochium nivale) increased from year to year. Eyespot, brown foot rot (after the first year) and sharp eyespot (which remained infrequent), assessed in summer (June), affected wheat more than barley. Eyespot severity was increased slightly on barley by treatments containing fluquinconazole, formulated with or without prochloraz, in the second year (third cereal), when it was also decreased slightly on wheat by fluquinconazole plus prochloraz, except in plots where the treatment had been applied for two successive years. The increases or decreases in eyespot in the second year were accompanied by, respectively, decreases or increases in the frequency of Idriella bolleyi where fluquinconazole was applied alone. Although the eyespot pathogen Tapesia yallundae (but not Tapesia acuformis) is sensitive to fluquinconazole in vitro, seed treatment, applied principally to control take‐all disease, is likely to have only a small effect against eyespot (or other stem‐base diseases), and then only on wheat and when formulated with prochloraz.
Differentiation of Three Varieties of Rhizoctonia circinata; var. circinata, var. oryzae and var. zeae on the Basis of Cellular Fatty Acid Composition
Authors: PRIYATMOJO A. , YAMAUCHI R. , CARLING D. E. , KAGEYAMA K. , HYAKUMACHI M.
Published: March 2003

Cellular fatty acid analysis was employed to differentiate three varieties of Rhizoctonia circinata; var. circinata, var. oryzae and var. zeae. Eight fatty acids including myristic (14 : 0), pentadecanoic (15 : 0), palmitic (16 : 0), palmitoleic (16 : 1 cis9), stearic (18 : 0), oleic (18 : 1 cis9), linoleic (18 : 2 cis9,12) and linolenic (18 : 3 cis9,12) acids were present in isolates of all three varieties of R. circinata. Heptadecanoic acid (17 : 0) was detected in isolates of R. circinata var. zeae but not in isolates of R. circinata var. circinata or R. circinata var. oryzae. Palmitic, oleic and linoleic acids were the major fatty acids found, comprising 94–98% of the whole‐cell fatty acid content. The remaining fatty acids were present in small amounts. Based on the composition (%) of fatty acids, isolates of R. circinata var. circinata, R. circinata var. oryzae and R. circinata var. zeae were clearly differentiated into three groups as shown by principal component and cluster analyses. This finding agrees well with the grouping of R. circinata into three varieties based on differences in colony morphology of the vegetative state. In principal component and cluster analysis, isolates of R. circinata var. circinata from Japan and Alaska were indistinguishable.
Molecular Evidence for the Presence of Aster Yellows‐Related Phytoplasmas in Lilies with Leaf Scorch and Flower Virescence
Authors: KAMIŃSKA M. , DZIEKANOWSKA D.
Published: March 2003

Severe leaf scorch symptoms occurred on oriental lily hybrids cv. Woodriff's Memory cultivated in two commercial greenhouses in Poland. Symptoms included leaf necrosis and malformation, flower bud abscission and flower virescence, distortion and abortion. Naturally infected lily plants with severe symptoms in 1999 had retarded growth and leaf chlorosis and they failed to flower the following year. The presence of phytoplasmas in diseased lilies was demonstrated using nested polymerase chain reaction (PCR) assays with universal and 16SrI group specific primer pairs that amplified the phytoplasma 16S rDNA fragment. The PCR products (1.1 kb) of all samples used for restriction fragment length polymorphism analysis had the same restriction profiles after digestion with endonucleases AluI and MseI. The restriction profiles of phytoplasma DNA from these plants corresponded to those of an aster yellows phytoplasma reference strain.
Presence of Leptosphaeria maculans Group A and Group B Isolates in Sweden
Authors: Kuusk A.‐K. , Happstadius I. , Zhou L. , Steventon L. A. , Giese H. , Dixelius C.
Published: March 2003

Leptosphaeria maculans isolates have been assigned to one of two groups, A or B, on the basis of differences in their characteristics. Group A can further be divided into pathogenicity groups (PG) 2, 3 and 4 and group B into PG1. To determine if isolates belonging to the aggressive canker forming group A are present in Sweden, physiological and genetic characterisation of 120 isolates collected in the year 2000 were performed. Thirty‐seven isolates were classified as belonging to pathogenicity group PG3 and 63 isolates as PG4, based on a cotyledon assay. Twenty isolates did not cause any symptoms at all, and were classified as PG1. When comparing two geographical regions, Skåne and Östergötland, equal numbers of PG3 and PG4 isolates were found. By analysing the isolates by PCR, the collection was further classified into 100 group A isolates and 20 group B isolates. A corresponding classification of the isolates was observed when the ability to produce pigments in Czapek Dox broth was examined. The results showed a clear predominance of group A. This was also the case for the isolate collection from 2001. In a detailed survey of disease development in a L. maculans infected winter oilseed rape field in southern Sweden (Skåne), basal stem canker was not observed until early June Although the disease index value increased from 8.4 in June to 18.0 in July, few severely damaged plants were observed before harvest in mid‐July, despite infection with group A isolates.
Induction of Peroxidase during Infection of Unripe Persimmon Fruit by Alternaria alternata: a Possible Quiescence Mechanism
Authors: Eshel Dani , Beno‐Moualem Delila , Lorang Jennifer M. , Dinoor Amos , Prusky Dov
Published: March 2003

Limited black spot symptoms (Quiescent infections) develop on persimmon fruits as Alternaria alternata hyphae penetrate the pericarp of green‐immature fruit. Inoculation of persimmon with A. alternata or treatment with a commercial preparation of purified cellulase induced similar black symptoms and higher peroxidase activity in green‐immature fruits but not in orange‐mature persimmon fruits. Both treatments induced the development of new peroxidase isoforms only in immature fruits – however, no effect was observed on polyphenoloxidase activity. A. alternata was transformed with a construct expressing green fluorescent protein (GFP). Histological analysis of hyphal development using GFP‐transformed fungi indicated that symptoms are always found ahead of the leading edge of the hyphae. We suggest that peroxidase increase, induced by the directly penetrating A. alternata, might be involved in the induction of quiescence infection by the pathogen in immature fruits.
RAPD Characterization of Fusarium oxysporum Isolates Pathogenic on Argyranthemum frutescens L.
Authors: Pasquali M. , Acquadro A. , Balmas V. , Migheli Q. , Garibaldi A. , Gullino M. L.
Published: March 2003

The random amplified polymorphic DNA (RAPD) technique was used to analyse total genomic DNA of 10 isolates of a new Fusarium oxysporum pathogenic on Argyranthemum frutescens (Paris daisy), by comparing them with representatives of the formae speciales basilici, chrysanthemi, cyclaminis, dianthi, gladioli, lilii, lycopersici, melonis, pisi, radicis‐lycopersici, tracheiphilum, and a non‐pathogenic isolate of F. oxysporum. A close genetic relatedness was observed among most of the new isolates from A. frutescens. These isolates also shared RAPD markers with the tested representatives of the forma specialis chrysanthemi. A single isolate among those tested from diseased A. frutescens was placed in a different cluster, which included representative isolates of forma specialis tracheiphilum. All the new isolates from A. frutescens, with the exception of the single divergent one, could be identified by their characteristic amplification profile, using selected random primers. A rapid protocol for DNA extraction directly from fungal colonies grown on Fusarium selective medium allowed the complete analysis in less than 4 h.
Plasma Levels of Catecholamines and Lipolysis During Starvation in Growing Pigs
Authors: Neubert E. , Scholze C. , Kratzsch J. , G H. , ürtler .
Published: March 2003

The aim of this study was to clarify the triggering mechanism of lipolysis in adipose tissue during feed withdrawal in pigs. Evaluation of blood samples drawn via an intravenous catheter from 10 growing pigs fasted for 60 h demonstrated, in addition to a haemodilution, a significant rise in plasma levels of non‐esterified fatty acids (250 ± 37 to 1427 ± 144 μmol/l) and free glycerol (98 ± 27 to 232 ± 41 μmol/l) within 48 h of feed restriction, and thereafter the concentrations levelled off. The pigs also showed a significant decrease in plasma levels of glucose (6.01 ± 0.20 to 4.62 ± 0.12 mmol/l) within 48 h of fasting, followed by repeated increase until the end of the experimental period. A significant decrease in plasma insulin‐like growth factor I (84 ± 13 to 65 ± 7 ng/ml) was observed after 16 h, which continued during the whole period of feed withdrawal. However, no significant changes in plasma levels of adrenaline and noradrenaline during the period of increased lipolysis were detected. Therefore, the observed stimulation of lipolysis in growing swine during fasting is not the result of an increase in plasma concentration of catecholamines.
Induced Hypocalcaemia by Na2EDTA Infusion. A Review
Authors: J R. J. , ørgensen . , Nyengaard N. R. , Daniel R. C. W. , Mellau L. S. B. , And . , Enemark1 J. M. D.
Published: March 2003

Disodium ethylenediaminetetraacetate (Na2EDTA) has been used in infusion studies in cows and other species for more than 35 years, primarily for the induction of hypocalcemia as a model for milk fever. This paper reviews such studies and discusses blood calcium kinetics, toxicology, changes in various blood parameters and the effect on blood circulation, cardiac function and smooth muscle motility in the gastro‐intestinal tract and in the pregnant uterus. It is concluded that Na2EDTA infusion may serve as a valid model for spontaneous hypocalcemia. However, experimental results may vary with factors such as the choice of method for blood total calcium analysis, and the rate of EDTA infusion. Standardization of these and certain other experimental conditions may greatly improve the comparability of results obtained in EDTA infusion studies. For cows, an infusion rate of 1.2 ml/kg/h of a 5 % (w/v) solution, corresponding to 0.25 mmol/kg/min, has been suggested as a standard infusion.
Spiramycin, Oxytetracycline and Sulphamonomethoxine Contents of Eggs and Egg‐Forming Tissues of Laying Hens
Authors: Furusawa N.
Published: March 2003

Spiramycin (SP), oxytetracycline (OTC) or sulphamonomethoxine (SMM) was fed to laying hens at a dietary level of 400 p.p.m. for 7 successive days. After 7 days of medicated feed, the concentrations of SP, OTC and SMM were determined in the blood, liver, ovary, oviducts (magnum and isthmus plus shell gland) and eggs (albumen and yolk) by high‐performance liquid chromatography. Of the three drugs, OTC showed the lowest content in the above tissues and eggs, while the reverse was true for SMM. Low concentrations of SP were measured in the blood, whereas contents in the liver and the oviducts were relatively much higher.
Suppression of Feed Intake after Parenteral Administration of D‐ββ‐Hydroxybutyrate in Pygmy Goats
Authors: Rossi R. , Örig S. D. , Del Prete E. , Scharrer E.
Published: March 2003

The effect of intraperitoneal injection of d,
l‐ or
d‐β‐hydroxybutyrate on feed intake and plasma metabolites was investigated in pygmy goats. The combined intraperitoneal injection of
d,
l‐βhydroxybutyrate or
d‐β‐hydroxybutyrate (15 mmol/kg0.75) and 1,3‐butanediol (6.6 mmol/kg0.75), a ketogenic substrate, decreased cumulative food intake while the same dose of 1,3‐butanediol or
dl‐β‐hydroxybutyrate alone had no effect. The decrease in food intake after combined injection of
d‐β‐hydroxybutyrate and 1,3‐butanediol was characterized by a significant decrease in meal frequency and a prolongation of the latency to eat. The hypophagic effect of the combined injection of
d‐β‐hydroxybutyrate and 1,3‐butanediol was significant for 8 h, while the hypophagia after
d,
l‐β‐hydroxybutyrate and 1,3‐butanediol was significant for only 2 h after injection. Injection of
d,
l‐β‐hydroxybutyrate increased plasma
d‐β‐hydroxybutyrate levels to 0.55 mmol/l and decreased plasma free fatty acids. Addition of 1,3‐butanediol (6.6 mmol/kg0.75) to the injection increased plasma
d‐β‐hydroxybutyrate level up to 0.75 mmol/l. The results show that parenteral administration of
d‐hydroxybutyrate reduces feed intake in pygmy goats and that the hypophagia appears to be related to the amount of
d‐β‐hydroxybutyrate injected. The hypophagia seems to be related to elevated plasma
d‐β‐hydroxybutyrate concentration, and the threshold concentration appeared to be about 0.7 mmol/l under the experimental conditions of this study.
Clinical Signs and Diagnosis of Scrapie in Italy: A Comparative Study in Sheep and Goats
Authors: Capucchio M. T. , Guarda F. , Pozzato N. , Coppolino S. , Caracappa S. , Di Marco V.
Published: March 2003

This article reports the clinical signs of scrapie occurring in sheep–goat flocks in Italy. The research, carried out on over 500 goats and 550 sheep, yielded an interesting clinical picture, especially of goat scrapie. The affected animals, aged between 2 and 8 years, showed neurological signs that could be classified into three categories: changes in mental status, abnormalities of movement and changes in sensation. Some general clinical signs were also observed. The clinical suspicion was confirmed by histopathological and biochemical investigations.
In Vitro Hepatobiotransformation of Sulphadimethoxine in Laying Hens
Authors: Furusawa N.
Published: March 2003

The biotransformation of sulphadimethoxine (SDM) was estimated in liver post‐mitochondrial supernatants (S‐9) from laying hens. The pathway and activity for hen S‐9 were compared with those for cow and pig S‐9. The formation of the hydroxylation of SDM, 6‐hydroxy SDM (6‐OH‐SDM), was found only with hen S‐9. The N4‐acetylating activity of SDM in hen S‐9 was lower than in cow and pig S‐9. All S‐9 from the three species de‐acetylated N4‐acetyl SDM (N4‐AcSDM). With respect to the hydroxylation and N4‐acetylation rates in hen S‐9, the values incubated at 41°C were higher than those at 37°C (P < 0.01).