bluuebunny/crossref_metadata_2025_split huggingface dataset:
Etude du mécanisme de la confusion sexuelle pour l'Eudémis de la vigne Lobesia botrana Den. et Schiff. (Lep., Tortricidae). I. Rôles respectifs de la compétition, du camouflage de la piste odorante et de la modification du signal phéromonal
Authors: Schmitz V. , Roehrich R. , Stockel J. 
Published: August 2009

AbstractDisruption mechanisms of pheromone communication in the European grape moth Lobesia botrana Den, et Schiff. — I Respective roles of competition, camouflage of female signals and modification of pheromonal signalThe mechanisms implied in confusion were studied by experiments in vineyard using the technique of males released and captured, completed in laboratory by tests in the olfactometer. The following results were found: (1) The sex behaviour of males was not inhibited by the presence of a source of synthetic pheromone up to the dose of 500 mg. (2) The main mechanism was the competition between females and source of synthetic pheromone. This competition was more and more favourable to the dispenser when the dose of pheromone increased. (3) It was also a camouflage of the smelling trail of the females. That caused a decrease of active space in which the males were able to locate the females. This effect was got for high doses only. (4) Addition of minor compounds of natural pheromone to synthetic products had no influence on competition and camouflage.RésuméLes mécanismes impliqués dans la confusion ont été étudiés par des expérimentations en vignoble basées sur la technique des lâchers et captures, et complétées au laboratoire par des essais en olfactomètre. Les résultats suivants ont été dégagés: (1) Le comportement sexuel des mâles n'est pas inhibé par la présence d'une source de phéromone synthétique jusqu'à la dose de 500 mg. (2) Le mécanisme principal est la compétition entre les femelles et les sources de phéromone synthétique. Cette compétition est de plus en plus favorable au diffuseur lorsque la dose de phéromone augmente. (3) II existe aussi un camouflage de la piste odorante des femelles amenant une diminution de l'espace actif dans lequel les mâles peuvent les repérer. Cet effet apparait pour les doses élevées de phéromone. (4) L'adjonction des composants minoritaires de la phéromone naturelle aux produits de synthèse n'a aucune influence sur la compétition et le camouflage.
Effect of temperature and plant size on the infestation dynamics of oilseed rape plants by Baris coerulescens Scop. (Col., Curculionidae) in field conditions
Authors: Lerin J. , Koubaiti K. 
Published: August 2009

AbstractThe plant infestation dynamics of winter oilseed rape, Brassica napus L. var. oleifera Metzger, by Boris coerulescens was investigated during a 3 years study in field conditions. Each year, plant infestation started at the end of March and reached a maximum ca. 23 June, then dropped drastically. Mortality was very low up to the maximum of population then increased abruptly. The main cause for mortality was plant desiccation caused by fungal diseases, harvest or degeneration of the cortex of the root. Mortality was higher in big plants than in small ones. Plant infestation can be described as a function of time by a logistic curve from the beginning to the end of the increase in population. Egg accumulation in plants is linearly linked to degree days during most of the ascending phase of plant infestation. The number of immature individuals per plant (from egg to nymph) is linearly linked to plant size, as measured from the root crown diameter. The relationship is density dependent. The infestation level at harvest is a very poor indicator of the overall level reached during the whole plant cycle because of higher mortality in big, heavily infested plants than in less infested small ones.
Diurnal change of adult behaviour, daily oviposition and influence of temperature on adult emergence and light trapping data of the beech caterpillar, Quadricalcarifera punctatella (Motsch.) (Lep., Notodontidae)
Authors: Kamala N. , Igarashi M. 
Published: August 2009

AbstractEcological properties of Quadricalcarifera punctatella adults needed in population studies were investigated. Diurnal changes of behavior were recorded by video camera. Adults emerged from dusk to midnight (1700–2400) with the peak between 2200–2300. Females copulated the 1st night, though most males began to copulate from the 2nd night. Almost all females began to lay eggs the 2nd night and oviposition continued for several days, with the peak being the 2nd–4th days after emergence. Since females laid several egg‐masses a day, time of oviposition varied greatly from dusk to dawn. Females laid several eggs before flying to a trap because they were not active the 1st night and because most of the trapped females had fewer eggs than the estimated fecundity. Adult emergence lasted for more than 1 month even in the laboratory and there was no difference in emergence curve between males and females. The number of emerged adults in the laboratory and that of adults trapped in the field both fluctuated greatly. Temperature influenced the numbers: many adults were caught on warm nights and only a few on cold nights. This was because high temperatures promoted the emergence and flight activity of the adults. Adults were caught in the field for about 2 months from late May to late July with a peak in mid‐ to late June; more than 75% of the total were caught during this period. Total number of trap catches from 11–30 June was concluded to be a good parameter for comparing annual changes in adult densities in future studies.
Aphid‐parasitoid interactions in a winter cereal crop: field trials involving insecticide application
Authors: Giller P. S. , Ryan B. , Kennedy T. , Connery J. 
Published: August 2009

AbstractLarge scale field trials were conducted to investigate aphid‐parasitoid interactions in winter wheat following spring applications of contact or systemic insecticides. Percentage parasitism was also investigated in the dominant aphid species using acrylamide‐gel electrophoretic methods. Sitobion avenae (F.) Metopolophium dirhodum (Walk.) and Rhopalosiphum padi (L.) were the commonest aphids and showed typical patterns of abundance through the growing season. Six parasitoid species were found: Aphidius rhopalosiphi de St.‐Per., A. ervi Hal., A. picipes (Nees) and Praon volucre (Hal.) being the most common primary parasitoids that attack the three main aphid species. The present work demonstrated a degree of temporal separation of these dominant cereal aphid parasitoid species which has rarely been documented. There was also evidence of earlier female activity in the crop in four of the six species. Parasitoid populations increased into June and peaked in July, coinciding with and continuing after peak aphid populations, before rapidly declining into August.Both contact and systemic insecticides sprayed in spring produced only a slight initial trend of suppression of aphid populations compared to control treatments; no influence on late summer populations was found. However, significant between‐field differences occurred. Neither contact nor systemic insecticides had any effect on population sizes, species composition or life history of aphid parasitoids (Braconidae; Aphidiinae, Aphelinidae) compared to control plots in the present study. Percentage parasitism was likewise unaffected by insecticides and reached a peak, based on electrophoretic methods, of 40% at peak aphid densities at the end of June. Estimates of parasitism based on presence of mummies were up to 10 times lower.Possible reasons for the lack of effect of insecticide application in the present study include timing of application (prior to main immigration period of aphids and parasitoids), mobility of populations and insecticide‐induced stimulation of reproduction in aphids.
Effect of pesticide residues on mortality of Aphytis melinus DeBach (Hym., Aphelinidae) in Munger cells and larger containers
Authors: Bellows T. S. , Morse J. G. , Gasto L. K. 
Published: August 2009

AbstractAn experimental study was designed to test the reliability of field‐usable bioassays in determining the toxicity of previously treated foliage to natural enemies. Lemon trees were treated at commercial rates with carbaryl‐oil, chlorpyrifos and methidathion. Residues on leaves and twigs were quantified weekly for 50 days after treatment. Bioassays of treated and control foliage to Aphytis melinus DeBach were conducted at similar intervals in Munger cells, 3.8 1 glass jars, and 2 1 paper cartons. Pesticide residues on twigs dissipated at approximately the same rates as residues on leaves. Bioassay mortality was high immediately following treatment. Subsequent mortality was reduced to near pre‐treatment and control levels quickly (3–8 days) in the cells, less quickly in the cartons, and slowest in the jars (up to 10 weeks). The mortality in the jars did not appear closely related to pesticide residue levels, but was possibly due to other contributing factors.
Within‐tree vertical pattern in Bactrocera oleae Gmel. (Dipt, Tephritidae) infestations and optimization of insecticide applications
Authors: Gaouar N. , Debouzie D. 
Published: August 2009

AbstractThe vertical pattern in olive fruit fly infestations was studied in the Tlemcen region (western part of Algeria) in 1990. The infestation rate of olives, measured by punctures, eggs, larvae, exit holes and pupae, was always higher in the lowest stratum (up to 2 m) than in the upper (3 m), the middle stratum being infested at an intermediate level. Differences were largest in October. In 1992 this result was used by spraying insecticide in an orchard half as intensely in the two higher strata as in the lower stratum. This led to relatively good protection in comparison with unsprayed orchard.
Phase variation—a possible adaptive character for the false spider mite, Brevipalpus phoenicis (Geijskes 1939)
Authors: Kennedy J. S. 
Published: August 2009

AbstractThe phenomenon of phase variation brought about by crowding has been proven to be an adaptive character for insects like locusts. Observations made on a cohort of Brevipalpus phoenicis (Geijskes) in groups of 50 individuals revealed that grouping shortens the developmental time and total life span and reduces the capacity for oviposition. This enables one to postulate a new hypothesis that during an epidemic outbreak and in the initial phase of colonisation the mites live longer and produce more eggs when the density of the population is lower until the population reaches a threshold level of crowding and vice versa. This phenomenon of phase variation brought about by the group effect is an adaptive character in the sense that when the density of the population is higher, the mites develop faster before the available food is exhausted.
Effects of the gregariousness of larvae in galls on the reproductive success of the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye (Dipt., Cecidomyiidae)
Authors: Soné K. 
Published: August 2009

AbstractThe effects of the gregariousness of larvae of the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye (Dipt., Cecidomyiidae), on the reproductive success of the midge were examined by field observations and laboratory experiments. The gregariousness of larvae in a gall did not cause the death of larvae in the gall, and the number of emerged adults per gall was expected to increase with the number of larvae per gall. Gregariousness decreased the size of larvae in galls. The decline in the larval size did not cause a simple decline in the number of eggs deposited per female. Females that emerged from medium size larvae deposited many more eggs than those from large and small larvae. The calculated number of eggs deposited per gall increased with an increase in the number of larvae per gall from one to five, but not when the number of larvae per gall was more than six. A simple model showed that if a female deposited about 10 eggs per egg cluster the number of eggs deposited by her daughters in the next generation would be maximum. The oviposition pattern and the gregariousness of larvae in galls in the field probably offer the midge the maximum reproductive success.
Thermal requirements ofDiaeretiella rapae(M'Intosh) on Russian wheat aphid (Diuraphis noxiaMordwilko, Hom., Aphididae) hosts
Authors: Bernal J. , González D. 
Published: August 2009

AbstractStudies were undertaken to assess the effect of temperature on development, and to estimate the thermal requirements (tandK) and upper developmental thresholds of three developmental periods (i.e. egg–mummy, mummy–adult, egg–adult) inDiaeretiella rapae(M'Intosh) (Hym., Aphidiidae) from China onDiuraphis noxia(Mordwilko) (Hom., Aphididae) hosts. Experiments were conducted at 5 constant temperatures: 10.0, 15.5, 21.1, 26.7, and 29.4°C (±1.0°C). Photoperiod and humidity conditions were maintained at 14L: 10D and 50–70% R.H., respectively. In general, the developmental times and rates for the three developmental periods inD. rapaewere influenced by the temperature to which they were exposed. Developmental times for the egg–mummy period increased from 7.3 days at 29.4°C to 28.5 days at 10.0°C; for the mummy–adult period from 4.6 days at 29.4°C to 20.0 days at 10.0°C; and for the egg‐adult period from 11.3 days at 29.4°C to 48.3 days at 10.0°C. At all five temperatures, the developmental times for the egg–mummy period were longer than the developmental times for the mummy–adult period. There were no differences in developmental times between males and females at the temperatures tested except at 15.5°C where males developed slightly faster than females (P < 0.011), i.e. 23.2 and 24.0 days, respectively. The estimatedtandKvalues were, respectively, 2.47°C and 198.99 degree‐days for the egg‐mummy period; 3.89°C and 106.45 degree‐days for the mummy–adult period; and 3.56°C and 292.29 degree‐days for the egg‐adult period. The upper developmental threshold for the three developmental periods is considered to be above, but near 29.4°C since the developmental rate decelerated but did not cease at this temperature.
Disruption mechanisms of pheromone communication in the European grape moth Lobesia botrana Den. & Schiff. (Lep., Tortricidae) II. Influence of the population density and the distance between insects for males to detect the females in atmosphere impregnated by pheromone
Authors: Schmitz V. , Roehrich R. , Stockel J. 
Published: August 2009

AbstractThe main consequence of mating disruption in the European grape moth is a decrease of female active space. Two experiments were done in a vineyard in order to evaluate the effect of population density and initial distance between insects on female detection by males.In the first experiment, two population densities corresponding to 10 and 20% infestation levels during the previous generation, were carried out in regard to two types of distribution of the population: low and high aggregates. Within these limits, population density had no influence on later attacks if the distribution was homogeneous, while, if the distribution was not homogeneous, attacks were more important.In the second experiment, colored males were released in areas with dispensers (1 and 500 mg of pheromone) and traps baited with one virgin female in a small cage. It was confirmed that the number of males trapped by females decreased when the dose of pheromone increased. Without pheromone, males scattered and may be captured at all distances. With pheromone, the nearest female only may be located by a male.RésuméEtude des mécanismes de la confusion sexuelle chez l'Eudémis de la vigne, Lobesia botrana Den et Schiff (Lep., Tortricidae). II ‐ Rôles respectifs de la densité de population et de la distance entre les insectes pour la détection des femelles par les mâles en atmosphère imprégnée de phéromoneChez L. botrana, la confusion sexuelle a pour conséquence majeure la diminution de l'espace actif de la femelle. Dans ce travail, deux expérimentations ont été réalisées en vignoble en vue d'évaluer l'effet de la densité de population et de la distance initiale entre les insectes sur la détection des femelles par les mâles.Dans la première expérience, deux densités de population, correspondant à des attaques de 10 et 20% des grappes lors de la génération précédente ont été réalisées selon deux types de répartition en vignoble (agrégats faibles et agréggats forts). Dans ces limites, la densité n'intervient pas sur les attaques ultérieures si la population est bien répartie, alors que, dans le case contraire, les attaques sont nettement plus abondantes.Dans la deuxième expérience, des lâchers de mâles d'élevage colorés étaient effectués en différents points des zones où étaient disposés des diffuseurs chargés de 1 ou 500 mg, face à des pièges englués appâtés d'une femelle vierge encagée. Il est confirmé que la proportion des mâles capturés par les femelles diminue quand la dose de phéromone augmente. En absence de confusion, les mâles se dispersent et peuvent être capturés à toutes les distances. En confusion, seule la femelle la plus proche peut être repérée par le mâle.
Potato tuber moth Phthorimaea operculella (Zeller) (Lep., Gelechiidae) and tuber infestation in Tunisian potato fields: analysis of the flight phenology
Authors: Roux O. , Baumgärtner J. 
Published: August 2009

AbstractFrom 1986 to 1991, pheromone traps were placed in Tunisian potato fields to record weekly the number of male Phthorimaea operculella (Zeller). The data were subjected to a time‐series analysis. The coincidence of social events with harvest practices are considered responsible for the relatively high number caught in 1986. In the subsequent years, the pheromone catches gradually decreased, and a linear model was used to remove this trend. A study of seasonality revealed a peak at the beginning of June and another increase in mid‐June leading to high catches beyond the period of spring potato crops. After removal of the seasonality the correlogram indicated a stationary stochastic process. By means of a spectral analysis, a four‐week cycle, presumably influenced by the moon, and a 10‐week cycle, due to unknown causes, were identified. Furthermore, there is an annual cycle related to increasing population densities in spring, i.e. the harvest time of the main‐season potato crop.
Dispersal of the spruce beetle, Dendroctonus rufipennis Kirby (Col., Scolytidae) from an experimental log deck
Authors: Safranyik L. , Shore T. L. , Linton D. A. , Taylor S. P. 
Published: August 2009

AbstractDispersal of spruce beetles from a log deck composed of infested (brood) and uninfested spruce logs was assessed by trapping emerged beetles and sampling logs for fresh attacks. The brood logs were dusted with fluorescent powder in order to mark beetles as they emerged. Two other log decks, composed of uninfested spruce, were built 25 m distant on opposite sides of the brood log deck to provide alternative host material for the dispersing beetles. About 14% of the emerged beetles attacked uninfested logs in the central deck and 25% attacked logs in the other two decks. The balance of the beetles dispersed beyond the experimental area.
Investigations on the nuclear polyhedrosis of teak defoliator, Hybhea puera (Cram) (Lep., Hyblaeidae)
Authors: Ahmed S. I. 
Published: August 2009

AbstractLaboratory and field studies on the nuclear polyhedrosis of teak defoliator caterpillars, Hyhlaeu pueru (Cram) were carried out to understand the insect‐virus relationship. The typical symptoms of nuclear polyhedrosis were observed in both naturally and artificially infected caterpillars. The natural incidence of the disease observed was 35.6%. Thenumber of polyhedral inclusion bodies (PIBs) per larva ranged from 1.12 times 10 to 2.37 times 10“ with an average of 1.973 times 10”.There was no correlation between the larval weight and number of PIBs estimated. The virulence of the NPV, measured in terms of total mortality and incubation period was reduced when PIBs of the virus were stored at room temperatur as a dry powder for a period of 6 years. The cross infectivity tests against the Achaea janata. Atteva fabriciella. Catopsilia crocale, Eligma narcissus, Euproctis fraterna and Eutectona machacralis proved negative. It was confirmed with the straining property of the polyhedra that the disease pathogen belonged to nuclear polyhedrosis virus (NPV)
Increased effectiveness and applicability of the sterile insect technique through male‐only releases for control of Mediterranean fruit flies during fruiting seasons
Authors: Hendrichs J. , Franz G. , Rendon P. 
Published: August 2009

AbstractOne of the main obstacles for a wider use of the Sterile Insect Technique (SIT) against the Mediterranean fruit fly (medfly) is the damage commercial fruit suffers due to sterile female stings. To overcome this obstacle, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has played a leading role in sponsoring and carrying out research to develop medfly genetic sexing strains that allow male‐only SIT releases.Recently, as a result of this continued FAO/IAEA effort, genetic sexing strains based on a temperature sensitive lethal (tsl) mutation have been developed at the IAEA Laboratories at Seibersdorf. Unlike previous pupal color sexing strains, these ‘second generation’ sexing strains allow female killing at an early (embryonal) stage. In addition, they are essentially stable under mass rearing conditions. This represents an important breakthrough because both of these attributes were considered indispensable for genetic sexing strains with any potential to replace conventional strains with both sexes in large scale sterile medfly production facilities. Besides the considerable savings in the costs of release and field monitoring, genetic sexing strains in field tests have shown severalfold increases in the effectiveness of the SIT as compared with the standard strains involving males and females. When releasing both males and females, sterile males are apparently not used effectively, because they use their limited sperm mostly to mate with sterile females and because they do not disperse widely in the presence of these females. When males only are released, however, they disperse much further in search of wild females and compete more intensely with wild males for wild females.As a result of the availability of usable male‐only strains, and the demonstration of their increased effectiveness, the applicability of the SIT against medfly has increased in two different ways. Highly developed commercial fruit growing regions, that previously had excluded application of SIT because of the fruit damage due to sterile female stings, are now reconsidering such free area/exclusion programs. More‐importantly, sterile male releases can now also be used for routine control purposes, rather than only for eradication programs, partially or fully replacing chemical bait‐sprays during the fruiting seasons.