bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of vitamin C and vitamin E on performance, digestion of nutrients and carcass characteristics of Japanese quails reared under chronic heat stress (34 °C)
Authors: Sahin K. , Kucuk O.
Published: March 2003

This study was conducted to determine the effects of vitamin C (L‐ascorbic acid) and vitamin E (DL‐α‐Tocopheryl acetate) on performance, digestion of nutrients and carcass characteristics of Japanese quails reared under chronic heat stress (34 °C). A total of 180 10‐day‐old Japanese quails were randomly assigned to six treatment groups, three replicates of 10 birds each. The birds with a 2 × 3 factorial design received either two levels of vitamin C (100 and 200 mg/kg of diet) or three levels of vitamin E (125, 250, or 500 mg/kg of diet). Then, 200‐mg vitamin C/kg of diet, compared with that of 100 mg/kg of diet, and higher dietary vitamin E inclusions resulted in a higher performance. The interaction between vitamin C and vitamin E for final body weight change (p=0.01) and feed efficiency (p=0.02) was detected. Final body weight change and feed efficiency increased to a higher extent by increasing dietary vitamin C when higher vitamin E levels were fed. Carcass characteristics improved with an increase of both dietary vitamin C and vitamin E (p=0.004). The interactions on carcass characteristics were all significant (p=0.02) and manifested themselves in a way that they were improved to a higher extent by an increase of dietary vitamin C when higher vitamin E levels were fed. Digestibility of nutrients (DM, OM, CP and EE) was greater with higher dietary vitamin C (p < 0.02) and also with higher vitamin E (p=0.07). There were no interactions detected for digestibility of nutrients (p=0.32). Taken together, the results of the present study conclude that a combination of 200 mg of vitamin C and 250 mg of vitamin E provides the greatest performance in Japanese quails reared under heat stress and can be considered as a protective management practice in poultry diet, alleviating the negative effects of heat stress.
Effect of protein : energy ratio in milk replacers on growth performance of goat kids
Authors: YEOM K‐H. , TRIERUM G. VAN , HACHE A. , LEE K.‐W. , BEYNEN A. C.
Published: March 2003

Two separate experiments were carried out to establish the effects of the protein : energy ratio in milk replacers on growth performance, plasma lipid concentrations and fatty acid composition in adipose tissue of male goat kids. In the first experiment there were 211 3‐day‐ old goat kids and in the second experiment there were 121 kids aged 3–7 days. The animals were fed ad libitum for a period of 4 weeks on milk replacers containing either 11.5 or 9.5 g crude protein/MJ metabolizable energy. In essence, protein was exchanged with fat on a weight basis. Milk concentrations were increased from 160 to 190 g/l in experiment 1, from 150 to 180 g/l in experiment 2. There were significant increases in body weight and feed intake when the milk replacer with high protein : energy ratio was fed. Group mean average daily weight gain was 168 and 203 g for the groups with low and high dietary protein : energy ratio in experiment 1; for experiment 2 the values were 139 and 160 g. Average dry matter intake was 18 and 14% higher for the diet with high protein : energy ratio in experiments 1 and 2, respectively. There was no change in either feed conversion (feed : gain ratio) or energy conversion (weight gain : energy intake ratio). There were no consistent diet effects on plasma lipid concentrations. Dietary fatty acid composition was reflected by that of adipose tissue. The milk replacer with high protein : energy ratio produced a small increase in the contents of myristic and palmitic acid in adipose tissue.
Effect of acetic acid consumption on clinical laboratory values in the dog
Authors: NAOUM H. , VAN NES J. J. , KAPPERT H. J. , BEYNEN A. C.
Published: March 2003

To investigate the influence of food enriched with acetic acid on the clinical, biochemical, electrolyte, blood gas, haematological and urinary variables in the dog, a cross‐over study was carried out with periods of approximately 2 weeks involving six healthy, adult dogs. Another objective was to determine the maximum concentration of acetic acid that the dogs found to be palatable. The dogs were maintained on a commercial meat‐based food with added acetic acid and/or glucose. The administered acetic acid was increased in stages. All dogs accepted the diet containing acetic acid at a level of 5% of metabolizable energy. Except for a decrease in plasma total protein, none of the variables were significantly affected by acetic acid consumption. Acetic acid feeding did not affect plasma acetate concentration and urinary acetate excretion, indicating that dogs efficiently metabolize ingested acetic acid.
Serum ascorbic acid concentrations in previously unsupplemented greyhounds after administration of a single dose of ascorbic acid intravenously or per os
Authors: Scott K. C. , Hill R. C. , Lewis D. D. , Gronwall R. , Sundstrom D. A. , Jones G. L. , Harper J.
Published: March 2003

Plasma vitamin C concentrations (mean + SD) were measured after a large (1 g) dose of vitamin C was administered orally or intravenously to each of four trained greyhounds in a randomized cross‐over design. Concentrations increased (p<0.05) for 2 h but returned to baseline by 6 h after supplementation. Peak concentrations were greater (p<0.01) after intravenous than oral administration (6.1±1.2 vs. 0.54±0.23 mg/dl). This suggests that vitamin C must be administered many times daily to maintain plasma concentrations above normal.
Field trial of an attractant mixture for dipterous, including the pest Ceratitis capitata (Wiedemann) (Dipt., Tephritidae), in Valencia, Spain
Authors: Casaña‐Giner V. , Gandía‐Balaguer A. , Primo‐Yúfera E.
Published: March 2003

In field trials of tentative lures for female Ceratitis capitata, made in two areas of Valencia (Spain), it was observed that a mixture, not previously described, of ethyl acetate, acetic acid and ethanol attracted dipterous of different species, some of them being pests of economic importance (including C. capitata). This mixture appears to be Diptera specific, and suitable for the monitoring or control of the identified species. Coboldia fuscipes Meigen, Drosophila funebris F. and Megaselia sp. are the most attracted.
Indigenous parasitoids (Hym., Chalcidoidea) of Phyllocnistis citrella Stainton (Lep., Gracillariidae) in Jaguariúna, São Paulo State, Brazil: preliminary results
Authors: Costa V. A. , De Sá L. A. N. , LaSalle J. , De Nardo E. A. B. , Arellano F. , Fuini L. C.
Published: March 2003

Abstract: The citrus leafminer, Phyllocnistis citrella Stainton, is native to Asia and was detected for the first time in Brazil in 1996. The objectives of this study were to conduct a survey of parasitoids attacking citrus leafminer in Jaguariúna, one of the citrus production regions of São Paulo State, Brazil, and to determine whether indigenous species were providing effective control of this pest species. The collections of new leaves were made weekly at citrus groves in Jaguariúna from October 1996 to October 1997. Of the six indigenous parasitoids which were found, Galeopsomyia fausta LaSalle was the most abundant parasitoid of P. citrella in this region, accounting for more than 90% of the specimens collected. Thus, this species is a serious candidate for biological control of the citrus leafminer in this region of Brazil. Other species collected were Horismenus sp., Cirrospilus ‘sp. C’, Elasmus sp., Eupelmus sp. and Conura (Ceratosmicra) sp. The mean percentage of parasitism was 39.28% (6.19−86.21%) in unsprayed orchards and 21.38% (1.33−56.63%) in orchards that were occasionally treated with fungicides, acaricides and insecticides Temik and Dipterex.
Effects of wheat foliar fungicides on the aphid endoparasitoid Aphidius rhopalosiphi DeStefani‐Perez (Hym., Aphidiidae) on glass plates and on plants
Authors: Jansen J. P.
Published: March 2003

Abstract: The side‐effects of several fungicides used in wheat to control disease at heading growth stage were assessed on the aphid parasitoid Aphidius rhopalosiphi by tests conducted in the laboratory on glass plates and in the greenhouse on young wheat plants. Very few formulations containing only one active ingredient (carbendazim, cyproconazole or epoxyconazole) or combinations of two (carbendazim + cyproconazole, carbendazim + hexaconazole) were harmless to A. rhopalosiphi in the glass‐plate tests. There was no apparent synergism between fungicides tested in combinations. The parasitoid mortalities in tests carried out on plants were less and chlorothalonil, epoxyconazole, fenpropidin, fenpropimorph, flusilazole, flutriafol, prochloraz, tebuconazole, tridemorph and a number of combinations (carbendazim + flutriafol, chlorothalonil + cyproconazole, epoxyconazole + tridemorph, chlorothalonil + hexaconazole, chlorothalonil + flutriafol, cyproconazole + prochloraz, epoxyconazole + fenpropimorph, fenpropimorph + propiconazole, propiconazole + tridemorph, triadimenol + tridemorph) were harmless or only slightly harmful to the aphid parasitoid. Several combinations (carbendazim + epoxyconazole, carbendazim + fenpropimorph, carbendazim + flusilazole, carbendazim + tebuconazole, chlorothalonil + fenpropimorph, chlorothalonil + flusilazole, fenpropimorph + fenpropidin, fenpropimorph + prochloraz, fenpropidin + propiconazole, fenpropidin + tebuco nazole, tebuconazole + triadimenol) were toxic for wasps on plants. The parasitoid mortalities were less on plants than on glass plates but the wasps spent less time on treated leaves and in some cases parasitism of aphids was reduced to a large extent. These results suggest that in addition to study of the direct effects of pesticides on beneficial insects (mortalities, reduction of fertility) their effects on the behaviour of the insects should also be studied. Products that induced a repellent effect need further testing in field or semi‐field conditions. However, many fungicide combinations that have little or no effect on A. rhopalosiphi can protect wheat against a wide range of diseases and the results obtained in this study indicate that an appropriate and effective protection of wheat at earing growth stage can be achieved with products that have no effects on aphid parasitoids.
Effects of 2,4‐D and maleic hydrazide on the glycogen level in the embryonic development of Pimpla turionellae (L.) (Hym., Ichneumonidae)
Authors: Özkan A. , Yanikôlu A.
Published: March 2003

Abstract: The effects of the herbicides 2,4‐D and maleic hydrazide, which are used against wild plants in farming, on the glycogen level in the embryological development of Pimpla turionellae, an important insect species used in biological control programmes, have been investigated. Various concentrations of the applied herbicides decreased the hatching rate and glycogen levels of the eggs which were still going through embryonic development. It was observed that the glycogen level of Pimpla turionellae eggs that were not exposed to herbicides increased after 4 and 8 h during embryonic development, but decreased in the later stages (24 and 30 h). It was found that the hatching rate and glycogen levels throughout the embryonic development decreased with as the concentrations of 2,4‐D and maleic hydrazide applied were increased.
Density of adult hoverflies (Dipt., Syrphidae) in sown weed strips and adjacent fields
Authors: Frank T.
Published: March 2003

In 1992 and 1993, studies examined numbers of adult hoverflies in sown weed strips, adjacent fields and a field boundary in the Swiss plateau, near Bern. Hoverflies were observed quantitatively and were divided according to their larval food. In both years, distinctly more aphidophagous and aquatic hoverflies were observed in the weed strips than in the adjacent fields. Copro‐ and phytophagous hoverflies were observed in very low numbers and they were almost entirely confined to the weed strips and the field boundary. The weed strips contained a high density of flowering plants and therefore proved to be very attractive feeding places for all hoverflies. Numbers of aphidophagous hoverflies declined slightly with increasing distance from the weed strips. Possible impacts of weed strips in encouraging aphidophagous hoverflies and their potential as aphid antagonists are discussed.
The effect of spruce cone insects on seed production in Switzerland
Authors: Seifert M. , Wermelinger B. , Schneider D.
Published: March 2003

Abstract: In 1989 and 1990, spruce cones were harvested at 29 sites distributed over the five main geographic regions of Switzerland, i.e. Jura, Central Plateau, North, Central and South Alps. The presence of insects and the species‐specific consumption of seeds was determined for each cone by examination of the median longitudinal section. Seven seed‐feeding species (Assara terebrella, Cydia strobilella, Dioryctria abietella, Eupithecia abietaria, Megastigmus strobilobius, Plemeliella abietina, Strobilomyia anthracina) and the spruce cone gall midge Kaltenbachiola strobi were found in the samples. The proportions of infested cones ranged from 36 to 100%. The regions did not show significant differences in terms of infestation rates, whereas differences between sites within the regions were highly significant. Seed loss ranged from 2 to 100%, its geographical distribution exhibiting a similar pattern to the infestation rates. Considering the number of infested cones, C. strobilella was the most abundant species, followed by K. strobi and P. abietina. Cones infested by conospermatophagous species (C. strobilella, D. abietella, E. abietaria) showed higher seed losses than those infested by spermatophages (M. strobilobius, P. abietina). Due to the ubiquitous occurrence of C. strobilella, its high infestation rates and the resulting seed losses caused by its offspring, this species has to be considered as the most important insect seed predator in Switzerland. A multiple linear regression analysis was carried out for each region to simultaneously explore the impact of site and tree variables as well as the effect of insect attack on the yield of viable seeds. The results indicate that site and tree conditions contributed more to the variability of seed yield than insect presence in a cone. The model predicted significant effects of insect attack mainly for cones with total seed numbers that were higher than the average.
Biologie d'Hippodamia variegata Goeze (Col., Coccinellidae) et possibilités de son utilisation contre Aphis gossypii Glov (Hom., Aphididae) sous serres de concombre
Authors: Habi M. El , Sekkat A. , Jadd L. El , Boumezzough A.
Published: March 2003

Abstract: Biology of Hippodamia variegata Goeze (Col., Coccinellidae) and its suitability against Aphis gossypii Glov (Hom., Aphididae) on cucumber under greenhouse conditions. Research work carried out in the laboratory has shown that temperature has a great effect on the development and the amount of feeding of Hippodamia variegata. The optimum temperature for its development and voracity approaches 26°C and the threshold development temperature is about 11.22°C. Investigations on its use in cucumber greenhouses against Aphis gossypii, the release of larvae and adult forms had shown satisfactory results. The efficiency level of this ladybird is a function of the ratio predator/prey and on the level of the aphid population at the moment of the ladybird release. The effect of density of the prey on the fecundity and the settlement of this ladybird under greenhouse conditions were also studied. The biological features and the efficiency of this ladybird are discussed.
Foraging habitats and foraging distances of bumblebees, Bombus spp. (Hym., Apidae), in an agricultural landscape
Authors: Walther‐Hellwig K. , Frankl R.
Published: March 2003

Abstract: In selected foraging habitats of an agricultural landscape flower visits of bumblebees and community structure of foraging bumblebees were studied, with special regard to the role of crops as super‐abundant resources. Most crops represent temporal foraging habitats with high abundance of bumblebees but mainly with low diversity in the bumblebee forage community, in contrast to permanent foraging habitats such as, for example, a hedgerow. The high numbers of bumblebees in the monoculture of crop plantations consisted mainly of short‐tongued bumblebee species. The role of foraging distances for the visitation rate of foraging habitats was studied by performing capture–recapture experiments with natural nests of Bombus terrestris, Bombus lapidarius and Bombus muscorum. Differences were found on the species as well as the individual level. The foraging distances of B. muscorum were more restricted to the neighbourhood of the nesting habitat than the foraging activity of B. terrestris and B. lapidarius. High percentages of B. terrestris workers were recaptured while foraging on super‐abundant resources in distances up to 1750 m from the nest. Isolated patches of highly rewarding forage crops, in agricultural landscapes, are probably only accessed by bumblebee species with large mean foraging distances, such as the short‐tongued B. terrestris. Species like the rare, long‐tongued B. muscorum depend on a close connection between nesting and foraging habitat. A restricted foraging radius might be one important factor of bumblebee species loss and potential pollinator limitation in modern agricultural landscapes. Furthermore, long‐distance flights of bumblebee pollinators have to be considered in the present discussion on gene flow from transgenic plant species on a landscape scale.
Auswirkungen von Diatomeenerde auf den Wasserhaushalt des Kornkäfers: Sitophilus granarius (L.) (Col., Curculionidae) und möglicher Einsatz innerhalb des Vorratsschutzes
Authors: Mewis I. , Ulrichs Ch.
Published: March 2003

Effects of diatomoceous earth on water content of Sitophilus granarius (L.) (Col., Curculionidae) and its possible use in stored product protection

Increased problems caused by application of chemical pesticides within pest protection has led to the demand for non‐polluting, biologically specific active countermeasures. This study aimed to test the possible use of diatomaceous earth against Sitophilus granarius. It will also examine the physiological effects of amorphous diatomaceous earth against this insect. After 2 weeks, 100% mortality was observed of the adults treated with 2 g Fossil Shield® per kilogram wheat, at 11–12% corn moisture content and relative humidity of about 62 ± 2%. The rise in grain moisture and relative humidity decreased the effectiveness of the Fossil Shield®. It was observed, that the diatomaceous earth reduced the number of adult granary weevils and increased the mortality rate at development stages, but they did not completely prevent the hatching of the next generation. After contact with diatomaceous earth, the individuals of S. granarius had lost weight and reduced their water content, respectively. The adults significantly lost weight and body water after 1 day exposure to Fossil Shield®. This showed that silica dusts break the water barrier of the cuticle. However, it increases the transpiration rate of water across the cuticle and several insects died through dehydration. At higher relative humidity diatomaceous earth was less effective toward S. granarius, because there was a lower permeability for water across the cuticle. This delays or rather prevents the drying action of diatomaceous earths. Furthermore, the addition of food affected the effectiveness of dusts against S. granarius. A lot of stored product beetles are able to produce metabolic water in the feed substrates. This ability protects them and works contrary to the loss of water.
Long‐term egg retention and parasitization in Trichogramma principum (Hym., Trichogrammatidae)
Authors: Reznik  , Voinovich  , Umarova
Published: March 2003

Laboratory experiments with Trichogramma principium Sug. et Sor. females that were offered Sitotroga cerealella Oliv. eggs demonstrated that less than half of the ovipositing females started oviposition during the first 2 days of the experiment, whereas the rest of the ovipositing females showed a delay in parasitization ranging from 2 to 10 days after contact with the host. Almost 10% of the wasps refused to parasitize the grain moth eggs over 12 days. The delay in parasitization may be as long as 6–8 days without any significant decrease in the number of mature ovarial eggs, in the number of eggs laid during the first 48 h of oviposition, and in the total lifetime fecundity. This egg retention is responsible for the fact that in spite of a relatively short mean duration of the oviposition period in each individual female (approximately 4 days), host parasitization by a group of simultaneously emerged wasps was almost uniformly distributed over 8–10 days. When induced, the parasitization state (i.e. the tendency to parasitize sequentially offered portions of host eggs) was stable both in the presence of a host and under host deprivation extended up to 8 days. These data provide further evidence for our hypotheses that the stability of the parasitization state in Trichogramma is based on endocrine mechanisms.
Evidence for the importance of odour‐perception in the parasitoid Rhopalicus tutela (Walker) (Hym., Pteromalidae)
Authors: Pettersson E. M. , Hallberg E. , Birgersson G.
Published: March 2003

Possible host location mechanisms in the chalcid wasp Rhopalicus tutela (Walker) (Hym., Pteromalidae), a parasitoid of the eight‐spined spruce bark beetle, Ips typographus (L.) (Col., Scolytidae), were examined. This was carried out in order to repeat and complement former studies on parallel parasitoid–scolytid systems that had contradictory results. Morphological examinations of the parasitoid antennae were made using both scanning and transmission electron microscopy. Possible functions of the sensilla placodea (multiporous plate sensillum), and other sensilla present on the antennae, have been indicated. For the first time, the placoid sensilla in a pteromalid parasitoid have shown porous walls and numerous innervations, which are typical characteristics for chemoreceptors. Previously the placoid sensilla have been suggested to be an infrared receptor. In order to test the chemoreceptive ability of R. tutela females and males, a synthetic reference blend was analysed by combined gas chromatography and electroantennographic detector (GC‐EAD). Their sensitivity to host‐related volatiles (such as certain pheromone components and oxygenated monoterpenes) was significantly greater than that for host‐tree‐related compounds (monoterpene hydrocarbons). Employing an infrared thermo‐scanner, the current study failed to detect ‘hot spots’ associated with susceptible hosts beneath the bark. Results from electrophysiology and electron microscopy revealed clear odour‐perceptive functions of the parasitoid antennae. These results strongly support the major importance of volatiles in host location by the bark beetle parasitoid R. tutela.
Life history of Amitus fuscipennis (Hym., Platygastridae) as parasitoid of the greenhouse whitefly Trialeurodes vaporariorum (Hom., Aleyrodidae) on tomato as function of temperature
Authors: De Vis R. M. J. , Fuentes L. E. , Van Lenteren J. C.
Published: March 2003

Life history parameters of Amitus fuscipennis MacGown and Nebeker as parasitoid of Trialeurodes vaporariorum (Westwood) were determined at 15, 20, 25 and 30°C on tomato using three different methods. For each method, immature development, mortality, longevity, fecundity, oviposition frequency and post‐oviposition period were determined and temperature‐dependent relations were estimated. Oviposition frequency was also estimated as a function of parasitoid age. Immature development had a maximum of 61 days at 15°C that decreased to 22 days at 30°C. Mortality in the grey stage was less than 2% at temperatures lower than 30°C, where it was 60%. Longevity fluctuated between 3 and 18 days. Fecundity increased from 338 eggs/female at 15°C to a maximum of 430 eggs/female at 25°C and then decreased to 119 eggs/female at 30°C. Oviposition frequency varied between 3 and 46 eggs/female per day and had its maximum on the first day after emergence of the parasitoid. Net reproduction rate, generation time and intrinsic rate of increase were calculated. The intrinsic rate of increase increased from 0.090 at 15°C to a maximum of 0.233 at 25°C and then decreased to 0.159 at 30°C. The influence of the methods to determine the life history parameters on the results is discussed. The results are compared also with the life history of Encarsia formosa Gahan (Hym., Aphelinidae) a parasitoid of the same host. The advantages and disadvantages of the pro‐ovigenic A. fuscipennis in comparison with the synovigenic E. formosa are discussed.
Field observations on the biology and behaviour of Dasiops caustonae Norrbom and McAlpine (Dipt., Lonchaeidae), as a candidate biocontrol agent of Passiflora mollissima in Hawaii
Authors: Causton C. E. , Rangel A. Peña
Published: March 2003

A newly described lonchaeid from Venezuela, Dasiops caustonae Norrbom and McAlpine, has been recommended as a biological control agent of Passiflora mollissima (H.B.K) Bailey, an aggressive exotic weed of Hawaiian rainforests. In this study, elementary biological information was collected in the field in order to determine the appropriateness of using D. caustonae as a biological control agent against this important weed. Field observations suggested that the host range of D. caustonae is limited to species of the subgenus Tacsonia. Female flies appear to mark flowers with an oviposition deterrent pheromone. This is possibly the first report of marking behaviour outside Tephritidae. The geographical range of this species is wide and comparable with that of the target weed. Life‐cycle studies demonstrated that D. caustonae is multivoltine with an estimated life‐cycle length of 3 to 4 months. Survival to adult was limited by premature flower fall, drought and interspecific competition by a bud and flower feeding Lepidoptera, Pyrausta perelegans Hampson. Additional ecological studies and host range testing of D. caustonae are recommended to determine its impact on the target weed and its safety as a biological control agent.
Pathogenicity of six isolates of Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina, Hyphomycetes) to Perillus bioculatus (F) (Hem., Pentatomidae)
Authors: Todorova S. I. , Cloutier C. , Côté J.‐C. , Coderre D.
Published: March 2003

Abstract:  The two‐spotted stink bug, Perillus bioculatus (F) (Hem., Pentatomidae) is considered an important predator of Colorado potato beetle egg masses and small larvae. The susceptibility of P. bioculatus second instar nymphs to six isolates of Beauveria bassiana (Balsamo) Vuillemin, which are highly pathogenic to Colorado potato beetle, was tested in the laboratory. Five isolates were highly pathogenic and caused more than 77% mortality after 8 days at a concentration of 106 conidia/ml. However, isolate IPP46 showed low pathogenicity and caused only 11% mortality of nymphs. The pathogenicity of isolates was independent of their host, source or country of origin. Isolate IPP46 was tested at six different concentrations. A linear relationship between the concentration of B. bassiana and the mortality of nymphs was observed. The 50% lethal concentration (LC50) value was 3.4 × 107 conidia/ml. The LT50 decreased with increase of conidia concentration used. The present results suggest that isolate IPP46 has good potential as a biological control agent within an integrated pest management programme.
Effects of gamma irradiation used to inhibit potato sprouting on potato tuber moth eggs Phthorimaea operculella Zeller (Lep., Gelechiidae)
Authors: Saour G. , Makee H.
Published: March 2003

Abstract: Different age groups of potato tuber moth, Phthorimaea operculella Zeller, eggs were exposed to gamma irradiation at incremental doses up to 150 Gy (the upper dose limit allowed for potato sprout inhibition). Young eggs were more likely to be sensitive to gamma irradiation than older eggs and the sensitivity level declined with age of the eggs. The exposure of 3–3.5‐day‐old eggs to 150 Gy resulted in a 26% increase in the egg incubation period compared with unirradiated eggs. The minimum dose required to prevent 4–4.5‐day‐old eggs from hatching was 1 kGy. When eggs were exposed to 75 Gy, 9.7% of larvae survived to the adult stage but emerged as deformed moths. At 100 and 125 Gy, 10.2 and 9.6% of larvae pupated, respectively, although no adult eclosion was recorded, whereas at 150 Gy, the larvae remained in mid‐instar stage and eventually died. Gamma irradiation doses applied to inhibit potato sprouting could be also considered as a valuable control tool against potato tuber moth infestations.
Daily flight activity of the western flower thrips (Thysan., Thripidae) in nectarine orchards in British Columbia, Canada
Authors: Pearsall I. A.
Published: March 2003

Abstract:  Hourly flight patterns of western flower thrips, Frankliniella occidentalis (Pergande) (Thysan., Thripidae) were assessed over a 24 h period in two nectarine orchards located in the Similkameen Valley, British Columbia, on 13 separate occasions between March and October 1994. The numbers of western flower thrips (male or female, dark or pale morphs) trapped per hour at between four to eight heights (0.25–2.00 m) were compared with temperature, wind speed, time of year and location of trap placement. Traps were placed within orchards, at the border of orchards and adjacent wild land, and within wildlands. Temperature and wind speed thresholds are defined, although the effect of wind speed varied with height of flight. Height of flight was affected by both the height of prevalent vegetation and temperature, with mean height of flight increasing linearly with temperature. Numbers of thrips in flight decreased with height of sticky trap from the ground. The pale morph was generally more common than the dark morph of western flower thrips. Males were not present until after emergence of the first generation in May, and were found at an approximate ratio of 4 : 1 (F : M) for the rest of the year. There were no differences between sexes or morphs of western flower thrips for location, height or daily patterns of flight.
Field establishment of Aphidius colemani Vier. (Hym., Braconidae, Aphidiinae) in the Czech Republic
Authors: Starý P.
Published: March 2003

Abstract: Aphidius colemani Vier. (a Chilean strain) was introduced and became established in the field between 1992 and 2000 in the Czech Republic. The target aphid species, Aphis spiraephaga Muell. on Spiraea ornamentals, and later the Russian wheat aphid, Diuraphis noxia (Kurdj.) on small grains were found parasitized, but an increasing number of other host aphid species in various urban ecosystems, crops and native communities was also detected. The establishment of A. colemani is classified as positive in supplementing the native parasitoid guilds as well as in contributing to the overall biodiversity of hymenopterous parasitoids in the cultivated landscape.
Studies on bacterial flora in the population of the fall webworm, Hyphantria cunea Drury. (Lep., Arctiidae)
Authors: Yaman M. , Nalçacıoğlu R. , Demirbağ Z.
Published: March 2003

Abstract:  In this study, the bacterial flora of Hyphantria cunea Drury. (Lep., Arctiidae) were investigated during three hazelnut seasons from 1998 to 2000. Four different bacteria were found in dead and living larvae. They were isolated and identified as Bacillus thuringiensis, Escherichia freundii, Micrococcus sp. and Streptococcus sp. Laboratory experiments carried out to determine the insecticidal activities of these isolates showed that E. freundii and Micrococcus sp. did not have any insecticidal effect on second – third instar larvae of H. cunea. However, B. thuringiensis and Streptococcus sp. had 56 and 38% effects, respectively. Crystals and spores from B. thuringiensis were also purified and the crystals, spores and crystals–spore mixture were tested separately against the larvae of H. cunea. It was found that the insecticidal activities of the crystals, spores and crystal–spore mixture were 37.5, 25 and 62.5%, respectively, on second – third instar larvae of H. cunea. These results indicate that the crystal–spore mixture has 6.5% more insecticidal effect than that of the vegetative cells of the B. thuringiensis isolate.
Oviposition preference of cotton leafhopper in relation to leaf‐vein morphology
Authors: Sharma A. , Singh R.
Published: March 2003

Abstract:  The oviposition preference of the cotton leafhopper, Amrasca biguttula biguttula (Ishida) was investigated in relation to leaf‐vein characteristics of 12 plant species, namely okra, cotton, castor, pigeonpea, cowpea, cluster bean, green gram, egg plant, sesame, country mallow, portia tree and shoe flower. Observations on the oviposition of the leafhopper under no‐choice conditions were recorded on three occasions during the peak period of leafhopper incidence in the field. On all three occasions the leafhopper rejected green gram, shoe flower and portia tree for egg‐laying, thereby indicating non‐acceptance of these plants for oviposition. For the remaining plants, the number of eggs per leaf differed significantly. Okra received the maximum number of eggs. The lateral veins of castor, cotton, cowpea, egg plant and country mallow leaves received more eggs in comparison with the main vein and subveins whereas in okra the subveins received the highest number of eggs followed by lateral and main veins. The leaves of cluster bean, pigeonpea and sesame were devoid of subveins. In cluster bean and sesame the lateral veins received more eggs than the main vein but in pigeonpea the main vein received more eggs than the lateral veins. Correlations of trichome density and length with the number of eggs laid in different veins were non‐significant. All types of veins in okra leaves were thicker than the rest of the test plants, which might have stimulated more egg laying in okra. The thickness of each category of vein, namely main vein (r=0.60), lateral veins (r=0.65) and subveins (r=0.56) was found to be positively correlated with the number of eggs laid. The length of the main and lateral veins were also found to be positively and significantly related to the number of eggs laid. It can be concluded from the present investigations that leaf‐vein thickness and length are crucial factors in influencing the oviposition behaviour of the cotton leafhopper.
Attractiveness of bait matrices and matrix/toxicant combinations to the citrus pests Iridomyrmex purpureus (F.Smith) and Iridomyrmex rufoniger gp sp. (Hym., Formicidae)
Authors: Stevens M. M. , James D. G. , Schiller L. J.
Published: March 2003

Abstract: Six bait matrices were tested for palatability to the ants Iridomyrmex purpureus and I. rufoniger gp sp., which are important pests of citrus in south‐eastern Australia. Granulated citrus pulp and rice bran impregnated with brown sugar were not accepted by either species, but ground dry dog food and ground insects (with or without added sugar) were highly attractive to both ant species. The ground dog food was impregnated with various toxicants at concentrations of up to 1% (w/w) and tested for palatability to both ant species. Technical grade pyriproxyfen, fipronil, and fenoxycarb were incorporated using organic solvents, whereas formulated fenoxycarb (Insegar®) was incorporated as an aqueous suspension prior to drying and granulation. Relative to the blank samples (carrier solvents only), bait acceptance by I. purpureus was not significantly reduced (P > 0.05) by any of the treatments except 1% technical fenoxycarb. Bait acceptance by I. rufoniger gp sp. was significantly suppressed by 0.2% fipronil, but not by higher concentrations. When water was used as the carrier solvent the blank sample was significantly (P < 0.05) less attractive to I. purpureus than the untreated control, suggesting that wetting of dog food‐based baits in field situations may irreversibly reduce their attractiveness. Laboratory colonies were used in choice and no‐choice tests to assess the efficacy of dog food baits containing fipronil (0.05–0.2% w/w). The corrected mortality for I. purpureus ranged from 88 to 100% and from 90 to 97% in the no‐choice and choice tests, respectively. In no‐choice tests I. rufoniger gp sp. corrected mortality varied from 52 to 60%, but in choice tests the corrected mortality did not exceed 26%. Ground dog food containing fipronil (0.05–0.2% w/w) has the potential to provide effective control of I. purpureus in citrus orchards, but alternative toxicants or lower fipronil concentrations may be required for control of I. rufoniger gp sp.
Resistance development in mosquito larvae Culex pipiens to the bacterial agent Bacillus thuringiensis var. israelensis
Authors: Saleh M. S. , El‐Meniawi F. A. , Kelada N. L. , Zahran H. M.
Published: March 2003

Abstract:  Mosquito larvae of Culex pipiens were subjected repeatedly to selection pressure with the bacterial agent Bacillus thuringiensis var. israelensis (B.t.i.) in the laboratory. Only 2.78‐fold increase in tolerance to B.t.i. was induced in C. pipiens as a result of 20 generations of selection. The tolerance of C. pipiens to B.t.i. decreased by about 58% after stopping the selection for three generations. Larval selection with B.t.i. caused a reduction in the reproductive potential of mosquito adult survivors but did not affect the adult longevity and the time of blood meal digestion ingested by female mosquitoes.
A New Genotype within Cucumber Mosaic Virus Subgroup I: Molecular Characterization of the Polymerase Encoding RNA 2 and its Capability to Overcome Replicase‐mediated Resistance
Authors: Hellwald K. ‐H. , Glenewinkel D.
Published: March 2003

A number of cucumber mosaic virus subgroup I strains originating from Asia were collected and tested for their ability to overcome replicase‐mediated resistance. Strains were inoculated to replicase‐mediated resistant plants transformed with a defective RNA 2 construct from Fny‐CMV. Most of the strains were able to overcome resistance to some extent. The resistance‐breaking capability of MB‐CMV, PRC‐CMV, C6‐CMV and 30RS‐CMV was higher in comparison with the other strains tested, based on the number of infected transgenic plants. The resistance‐breaking capability of MB‐CMV and PRC‐CMV was mapped to RNA 2 of these strains. The nucleotide sequences of MB‐CMV RNA 2 was determined and compared with other CMV subgroup I strains. Data obtained showed that MB‐CMV differs from all other strains by more than 7% in nucleotide sequence identity. This indicates a high genetic variability within CMV subgroup I strains from Asia based on RNA 2.
Effet de L'acide Caféoylshikimique des Racines du Palmier Dattier sur L'activité et la Production des Enzymes Hydrolytiques de Fusarium oxysporum f. sp. albedinis
Authors: Modafar C. El , Tantaoui A. , E l Boustani E.
Published: March 2003

L'acide caféoylshikimique (ACS), composé phénolique soluble majeur des racines du palmier dattier, représente l'un des facteurs de résistance de l'hôte au Fusarium oxysporum f. sp. albedinis. L'ACS est testéà différentes concentrations (0,25 à 3 µ mol/ml) sur l'activité et la production d'enzymes hydrolytiques de F. oxysporum f. sp. albedinis dans le filtrat de culture. Les enzymes étudiées sont les protéases, les cellulases, les pectineméthyl‐estérases (PME), les polygalacturonases (PG) et les polygalacturonate trans‐éliminases (PGTE). Les résultats obtenus montrent que l'ACS affecte très peu l'activité des différentes enzymes alors qu'il réduit fortement leur production. La croissance mycélienne du champignon est également affectée par l'ACS, mais elle ne permet pas d'expliquer à elle seule la forte réduction de la production des hydrolases. Afin d'expliquer cet effet différentiel de l'ACS sur l'activité et la production d'enzymes lytiques parasitaires, nous avons testé d'une part, l'effet des produits d'hydrolyse de l'ACS (acide caféique, acide shikimique) et d'autre part, l'effet des produits d'oxydation de l'ACS (quinones) obtenus par oxydation via la tyrosinase. Les résultats obtenus montrent que l'acide shikimique n'a pas d'effet significatif sur l'activité des hydrolases et ne présente qu'une faible inhibition de leur production. Quant à l'acide caféique, il présente un pouvoir inhibiteur plus important sur l'activité des différentes enzymes que celui de l'ACS et son effet inhibiteur se manifeste davantage sur leur production. L'oxydation de l'ACS par la tyrosinase se traduit par une forte inhibition de l'activité des différentes enzymes étudiées. Cette inhibition est sensiblement comparable à celle observée par l'ACS non oxydé sur la production des enzymes. De même, l'acide caféique oxydé manifeste un effet inhibiteur plus important sur l'activité des hydrolases que celui de l'acide caféique non oxydé. L'ensemble de ces résultats suggère que l'ACS génère des produits d'hydrolyse (notamment l'acide caféique) et des produits d'oxydation (quinones) qui inhibent l'activité des enzymes protéolytiques, cellulolytiques et pectinolytiques produites par F. oxysporum f. sp. albedinis dans le milieu de culture.
Occurrence of Pseudomonas avellanae (Psallidas) Janse et al. and related pseudomonads on wild Corylus avellana trees and genetic relationships with strains isolated from cultivated hazelnuts
Authors: Scortichini M. , Marchesi U. , Angelucci L. , P. Rossi M. , Dettori M. T.
Published: March 2003

Surveys in submediterranean forests of central Italy were carried out during 1996–98 to verify the possible presence of bacterial canker caused by Pseudomonas avellanae in wild hazelnut trees (Corylus avellana L.). Wilted twigs were noticed several times especially in summer. In other cases, wild C. avellana trees growing near to hazelnut orchards appeared completely wilted. Isolates that were pathogenic to C. avellana, showing a different degree of virulence, were obtained in both situations. Biochemical, physiological and nutritional tests as well as the comparison of whole‐cell protein profiles, revealed the presence of 16 isolates identical to P. avellanae reference strains that had previously been isolated in the same area and five deviating isolates. Repetitive‐PCR genomic fingerprinting performed by using BOX (Box elements), ERIC (Enterobacterial Repetitive Interkingdom Consensus) and REP (Repetitive Extragenic Palindromic) primer sets and analysed by means of upgma, revealed the existence of two main groups of pseudomonads pathogenic to C. avellana. Group A includes P. avellanae strains isolated in northern Greece and central Italy as well as the isolates obtained from the wild C. avellana trees grown near the cultivated hazelnut orchards. Group B includes strains previously isolated in northern, southern and other areas of central Italy as well as the isolates obtained from C. avellana wild trees showing twig dieback. Control measures should be taken to avoid the spread of bacterial canker of hazelnut in the forests of central Italy.
Light‐Dependent Induction of Sekiguchi Lesion Formation by Bipolaris oryzae in Rice cv. Sekiguchi‐asahi
Authors: Arase S. , Fukuyama R. , Honda Y.
Published: March 2003

The effect of light irradiation on Sekiguchi lesion formation induced by infection with Bipolaris oryzae on rice sl mutants was investigated. Although the Sekiguchi lesions formed exclusively under daylight fluorescent lamps, brown spots and necrotic spot lesions formed in the dark. The Sekiguchi lesions were larger than the brown spot lesions. When leaf blades inoculated with B. oryzae were irradiated through band‐pass filters of BPB‐45, BPB‐50, BPB‐55, and BPB‐60, Sekiguchi lesions were formed regardless of the BPB filters' wavelengths. Under black‐light lamps, near‐infrared fluorescent lamps, or in the dark, however, brown spot lesions were induced by B. oryzae. The effective wavelength region for light‐dependent Sekiguchi lesion formation was 400–700 nm. Furthermore, there was a direct correlation between the length of the radiation wavelengths and the size of the Sekiguchi lesions.
Light‐Enhanced Resistance to Magnaporthe grisea Infection in the Rice Sekiguchi Lesion Mutants
Authors: Arase S. , Fujita K. , Uehara T. , Honda Y. , Isota J.
Published: March 2003

The rice sl mutant showed two types of responses to Magnaporthe grisea infection by light treatments. One was an sl‐mutant‐type response characterized by Sekiguchi lesion expression under light waves of 400–700 nm, and the other was a wild‐type response characterized by blast and/or necrotic spot lesion expression in the dark or at wavelength between 290 and 330 nm. There was a large difference in the resistance to M. grisea infection between the mutant‐ and wild‐type responses in the rice sl mutant. When the mutant‐type response was induced in the rice sl mutant, the disease resistance was enhanced relative to that in the wild‐type response. Enhanced resistance was demonstrated by two components: (a) the number of Sekiguchi lesions was reduced relative to that of blast or necrotic lesions; (b) sporulation of M. grisea was not induced in Sekiguchi lesions. The enhanced resistance was dependent on light of 400–700 nm.
Differentiation of Xanthomonas campestris pvs. pelargonii and hederae by Polymerase Chain Reaction
Authors: Sulzinski M. A.
Published: March 2003

Geranium isolates of Xanthomonas campestris pv. pelargonii (Xcp) and English ivy isolates of X. campestris pv. hederae (Xch) were tested by polymerase chain reaction (PCR) to determine whether the two pathovars could be discriminated using amplification conditions developed to identify and detect Xcp in infected geraniums. Using PCR, other workers reported that the genomes of Xcp and Xch were indistinguishable. The objective of this study was to determine whether the two pathovars have sufficient sequence diversity to allow them to be distinguished by molecular means. Three primer pairs were used for PCR amplification. Two of the primer pairs (REP and XcpM1/XcpM2) were able to distinguish between Xch and Xcp, whereas amplification with the third primer pair (ERIC) did not allow discrimination between the two pathovars. Based on PCR amplification, Xcp and Xch are distinctly different pathovars. Additionally, all three primer pairs showed discrimination between Xcp and Acidovorax, a bacterial pathogen that induces leaf spot on geranium.
Restriction Fragment Length Polymorphism Markers to Characterize Plasmodiophora brassicae Single‐spore Isolates with Different Virulence Patterns
Authors: Klewer  , Luerßen  , Graf  , Siemens
Published: March 2003

Plasmodiophora brassicae‐specific clones were used to establish restriction fragment length polymorphism (RFLP) markers for four single‐spore isolates of P. brassicae, which were originally selected from the field isolate ‘e’ and could be distinguished by infection tests with a small differential Arabidopsis thaliana set. The poor yield of DNA from the obligate biotrophic parasite was overcome by extracting DNA from young diseased roots of Brassica rapa. This mixture of host and parasite DNA was employed for RFLP and fingerprint studies utilizing selected P. brassicae‐specific clones as hybridization probes.
Induced Resistance in Cucumbers against Fusarium oxysporum f. sp. cucumerinum and Rhizoctonia solani AG2–2 by Infection of the Cotyledons
Authors: Kubota  , Abiko
Published: March 2003

Localized infection in cucumber cotyledons with Colletotrichum lagenarium induced resistance against infection after challenge inoculation with Rhizoctonia solani AG2–2 and Fusarium oxysporum f. sp. cucumerinum in the roots. The plants were unprotected in soil that was infested heavily with R. solani or in contact with the mycelium, and induced resistance was not observed. Wounding of the root also negated the effect of induced resistance to F. oxysporum.