bluuebunny/crossref_metadata_2025_split huggingface dataset:
The survival of developmental Sitophilus granarius (L.) subjected to constant and fluctuating temperatures between 0 and 10°C.
Authors: Fleming D. A. , Armitage D. M. 
Published: November 2017

Abstract

Surface infestations of grain weevils, S. granarius, have occurred during mid-winter in commercial aerated stores and in 20-tonne cooled bins when the grain was stored over 2 seasons and temperatures were rarely above 5°C. It was hypothesised that they were the result of eggs laid in the summer, which had continued to develop through the autumn and early winter and emerged in mid-winter when fluctuating temperatures at the surface permitted this. Therefore, this study was set up to discover what proportion of developing stages of different ages could survive exposure to steady temperatures between 0 and 10°C which coincide with the temperatures attained within the bulk of most stored grain in the UK. The effects of a temperature fluctuating between 0 and 10°C were also studied as this approximates the extreme fluctuations that might be expected at the surface of a cooled bulk in winter. Steady temperatures below 5°C were successful in killing all developmental stages within 7 weeks and are achievable in most years in the UK However, when the temperatures were allowed to cycle between 0 and 10°C, it extended the time needed to eliminate all developing stages to more than 16 weeks. It is unlikely that this temperature-time combination could be achieved in the UK. It is therefore quite likely that a mixed-age infestation of developing grain weevils inside the grain could survive the fluctuating temperatures that occur at the grain surface.
Treatment of an empty fumigation chamber using the Degesch phosphine generator.
Authors: Mathews M. , Luzaich G. 
Published: November 2017

Abstract

A trial fumigation was conducted on an empty fumigation chamber using the Degesch phosphine generator. The Degesch phosphine generator is a device for the rapid production and injection of phosphine gas into structures requiring fumigation. The generator is positioned outside the structure where it generates phosphine by reaction of Magtoxin granules, a high-assay magnesium phosphide product, with water. This reaction is carried out inside the generator under an atmosphere of carbon dioxide. The phosphine (PH3) is then pumped from the generator into the structure through a recirculation system. The generator produces a non-hazardous, aqueous slurry (pH 7) of magnesium carbonate which requires disposal. The carbonate contains less than 0.001% unreacted phosphide. A fumigation chamber with a volume of 2633 m3 (93 000 ft3) was dosed at a rate of 1.1 g PH3/m3 (32 g PH3/ft3). This dosage corresponds to a theoretical concentration of 800 ppm PH3. A concentration of 800 ppm was reached in the chamber approximately 52 minutes after injection of phosphine began. Phosphine concentration measurements were made at the bottom, middle and top of the structure over a 96-hour fumigation. Some advantages of the Degesch phosphine generator are: rapid production of high concentrations of phosphine; lower labour requirement for application, retrieval of spent fumigant, and disposal; ease of redosing or adding back phosphine; generation of phosphine gas is not dependent on ambient temperature or humidity; application may be started and stopped at any time; multiple fumigations can be conducted from a central location using a gas distribution system; worker exposure during application is virtually eliminated; may be used with the J-System, a patented method for the recirculation of phosphine gas, to obtain uniform distribution of phosphine throughout the treated commodity; and can serve as an alternative to methyl bromide.
Effect of fumigation temperature on the efficacy of phosphine against strongly resistant psocids Liposcelis bostrychophila (Psocoptera: Liposcelididae).
Authors: Nayak M. K. , Collins P. J. , Pavic H. 
Published: November 2017

Abstract

Four concentrations of phosphine (0.1, 0.17, 0.3 and 1 mg/litre) were evaluated for their effectiveness against the strongly resistant L. bostrychophila at fumigation temperatures of 20, 25, 30 and 35°C. The lowest number of days required to achieve population extinction was evaluated. At any fixed concentration of phosphine, the number of days to population extinction decreased as the fumigation temperature increased from 20 to 30°C. At 0.1 mg/litre and 20°C, more than 14 days were required to completely control the insects; at 30°C, only 7 days were required. The increase in the fumigation temperature from 25 to 30°C substantially reduced the exposure period needed to achieve population extinction of resistant psocids.
Prospects for predicting insect mortality in relation to changing phosphine concentrations.
Authors: Daglish G. J. , Collins P. J. , Pavic H. 
Published: November 2017

Abstract

The effects of varying phosphine concentrations (0.2, 0.4 and 0.43 mg/litre) on phosphine-resistant Rhyzopertha dominica (QRD569) and Sitophilus oryzae (QSO335) strains from Australia were studied under fumigation (25°C and 55-60% relative humidity) and post-fumigation (25-28°C and 55-60% relative humidity) conditions to evaluate the prospect of predicting insect mortality under varying phosphine concentrations. The commonly used concentration × time product was unreliable for the prediction of R. dominica and S. oryzae mortality. On the other hand, the relationship Cnt=k may be useful for R. dominica. However, in the case of S. oryzae, the relationship Cnt=k proved to be less reliable.
The efficacy of flufenoxuron and azadirachtin against mixed mite and insect populations in small bins of wheat.
Authors: Collins D. A. 
Published: November 2017

Abstract

Alternatives to the use of organophosphorus compounds for the protection of stored grain against pest infestations were investigated. Batches of wheat (cv. Mercia) were treated with 2 mg flufenoxuron and 75 mg azadirachtin/kg, transferred into small bins infested with mixed populations of mites and insects (Acarus siro, Lepidoglyphus destructor, Sitophilus granarius and Oryzaephilus surinamensis) and stored at 15°C and 80% relative humidity for 26 weeks. From the second week, efficacy was evaluated every four weeks based on the ability of the compounds to inhibit the development and survival of the pest species. A. siro or L. destructor were not detected in the samples treated with flufenoxuron at or after 6 and 10 weeks, respectively. In the azadirachtin-treated samples, mites were not detected at weeks 2 and 26, when A. siro were found in one of the bins. L. destructor was not detected in any of the untreated samples after week 14, which may have been due to competition from the faster breeding A. siro. Adult beetles were caught in the traps throughout the experiment, with lower numbers of O. surinamensis trapped than S. granarius. The treatments reduced the numbers of S. granarius by approximately 75%.
The importance of moisture changes at the grain surface.
Authors: Armitage D. M. , Cook D. A. 
Published: November 2017

Abstract

Studies are presented on seasonal changes in moisture content at the grain surface, diurnal changes in relative humidity (rh) and surface moisture uptake, effect of aeration on surface moisture uptake, effect of bulk moisture content and sealing on surface moisture uptake, and effect of bulk moisture content on mite populations, particularly those conducted on wheat and barley. To evaluate whether surface uptake could be limited to control mite (Acarus siro and Lepidoglyphus destructor) populations, bins containing 25 kg of wheat were held at constant conditions of 15°C and 80% rh, and sealed with shrouds of nylon woven tarpaulin, plastic sheeting (nylon polythene laminate) or butyl rubber, or left uncovered as a control. The controls steadily absorbed moisture and had a median surface mc of 16.3% after 18 weeks. The shrouded replicates also steadily absorbed moisture but the uptake was reduced by 0.5-1%, depending upon the material. The plastic sheeting resulted in the lowest mc and mite infestation (a reduction of approximately 10-fold for A. siro) after 18 weeks.
Phosphine resistance in Lasioderma serricorne (F.) (Coleoptera: Anobiidae).
Authors: Savvidou N. , Mills K. A. , Pennington A. 
Published: November 2017

Abstract

Thirty-one strains of the cigarette beetle, L. serricorne, collected from tobacco in 25 countries were established on laboratory diet over a three-year period. Fourteen strains were tested with seven concentrations of phosphine (0.0034 to 0.855 g/m3) and used to develop a mortality test for phosphine resistance based on the test for other storage beetles produced by the Food and Agriculture Organization. From their probit response lines, a discriminating concentration was set at 0.17 g/m3, for 20 h, and at 25°C and 60% relative humidity. Of the 31 strains tested, 17 (55%), which originated from 12 countries and with two of unknown origin, were designated as resistant. One of the resistant strains was subjected to further treatments of phosphine to select a population homozygous for at least one major gene for phosphine resistance. Adults from this strain survived five times the discriminating concentration and the homozygous population was subsequently used in virgin crosses with the laboratory-bred, susceptible strain to produce heterozygous insects. Both the homozygotes and the heterozygotes were used to develop a more rapid knockdown resistance test, which would give results within a working day. This test requires treatment of adults with a concentration of 0.476+0.09 g/m3 phosphine for 2 h and 45 minutes.
The use of phosphine as an alternative to methyl bromide for the disinfestation of palm dates.
Authors: Mills K. A. , Wontner-Smith T. J. , Cardwell S. C. , Bell C. H. 
Published: November 2017

Abstract

Trials in a Tunisian date processing facility were carried out with phosphine as a methyl bromide alternative for the control of the larvae of the carob moth, Ectomyelois ceratoniae [Apomyelois ceratoniae], and of eggs laid on dates during processing. The dates were transferred into plastic mesh crates used for regular storage. Bioassays of larvae-infested dates together with eggs of the mill moth, Ephestia kuehniella, used as a closely related model for the control of Ectomyelois ceratoniae eggs, were included in treatments monitored for temperature and gas concentration in sheeted stacks. These were carefully sealed and vacuum-tested with poly(vinyl chloride) covering sheets and polyethylene base sheets. Two freight containers were modified as electrically heated fumigation chambers to allow dates to be heated before treatment to a maximum of 30°C to shorten exposure periods without impairing date quality. Cooling of the dates occurred during the treatments. Aluminium phosphide tablets and cylinderized ECO2FUME were used in monitored trials at a theoretical maximum concentration of between 1.5 and 1.8 g/m3. Only the larvae-infested dates were available for the majority of trials in heated containers. At 15-30°C, larval control was obtained with a 3-day exposure period and a 2-day exposure with ECO2FUME. In a stack at an average temperature of 23°C, E. kuehniella eggs survived a 7-day but not a 10-day exposure period. In the heated container, the eggs survived a 5-day but not a 7-day exposure period at an average of 25°C. In the absence of trials at lower temperatures, recommended exposure periods for the control of E. ceratoniae under these fumigation conditions were 10, 7, 5 and 3 days at 15, 20, 25 and 30°C, respectively. No impairment to the palatability of the dates was noted in any trial.
The use of carbon dioxide as an alternative to methyl bromide for the disinfestation of palm dates.
Authors: Mills K. A. , Wontner-Smith T. J. , Cardwell S. C. , Bell C. H. 
Published: November 2017

Abstract

Trials in a Tunisian date processing facility were carried out with carbon dioxide as an alternative to methyl bromide for the control of the larvae of the carob moth, Ectomyelois ceratoniae [Apomyelois ceratoniae], and of eggs laid on dates during processing. Dates were transferred into plastic mesh crates used for regular storage. Bioassays of larvae-infested dates were included in treatments closely monitored for temperature and gas concentration, together with eggs of the mill moth, Ephestia kuehniella, used as a closely related model for the control of Ectomyelois ceratoniae eggs in various enclosures. In all trials, the concentration was kept at or more than 40% by the addition of gas when appropriate. Dates were treated in carefully sealed and vacuum-tested stacks, using either PVC [poly(vinyl chloride)] covering sheets and polyethylene base sheets or PVC covering and base sheets. At ambient temperatures of 15-25°C, exposure periods for larvae and eggs were 7 and 10 days, respectively. Two freight containers were modified into electrically heated fumigation chambers to allow dates to be heated before and during treatment to a maximum of 30°C to shorten exposure without impairing date quality. The containers were pressure-tested before and after sealing modifications. At 30°C, an exposure period of 4 days controlled both developmental stages. Vacuum chambers in the plant were not sufficiently gas-tight to carry out trials without re-establishing vacuum and modifying rates daily. Under such conditions, larval and egg bioassays showed survival in a 4-day exposure period. Trials conducted in a more gas-tight chamber showed that immature Rhyzopertha dominica survived a 5-day exposure period. Hence, the use of CO2 under vacuum even in improved chambers at temperatures above 15°C appears to require an exposure of 6 days. There was little advantage in using high capital-cost vacuum treatments for the control of larvae, although it was beneficial for the control of eggs. Trials in chambers at atmospheric pressure showed that dates do not significantly sorb CO2. No impairment to the palatability of the dates was noted in any trial.
Emission, entry and deposition of pesticide spray on neighbouring nontarget areas after fogging warehouses with Detmolin F® (dichlorvos).
Authors: Klementz D. , Reichmuth C. , Holdt G. 
Published: November 2017

Abstract

Detmolin (dichlorvos) residues in the air after fogging were studied in Brandenburg, Germany during 1999-2001. The level of active substance contained in the air of the store, at the store's windows and ventilation points, and at 5, 10, 20 and 50 m downwind of the building at a height of 1.6 m was measured using adsorption tubes. With an application of 6 litre Detmolin F/1000 m3, the maximum concentration of the active substance found in the six trials was 95 mg/m3 in the stores. The maximum concentration at windows and doors was measured when these were opened 4 or 6 hours after treatment. Depending on wind speed and temperature, concentrations fluctuated between 100 and 550 µg/m3. Pesticide concentrations in nontarget areas clearly decreased both with increasing time after treatment and with increasing distance from the treated store. Deposition was measured both in model standard waters (steel tubs) and on filter paper. Maximum concentrations of the active substance in water were found in four trials, in the water samples drawn 5 m from the store 24 h after application. These concentrations ranged from 5 to 50 µg/litre.
Repellency and toxicity of essential oils from Ocimum gratissimum (Lamiaceae) and Laurus nobilis (Lauraceae) from Georgia against the rust-red flour beetle (Tribolium castaneum Herbst) (Coleoptera: Tenebrionidae).
Authors: Andronikashvili M. , Reichmuth C. 
Published: November 2017

Abstract

Six essential oils, three of which were obtained from Laurus nobilis (leaves, branches and stems) and three from Ocimum gratissimum (whole plant) samples from Georgia, USA, were evaluated for repellency and toxicity properties against T. castaneum. The content of the oils in 500 µlitre with acetone as the solvent varied from 0.0625 to 5.0000 µlitre/ml. Repellency tests on impregnated filter paper demonstrated pronounced differences in the number of insects repelled with the six samples of L. nobilis and O. gratissimum oils. The degree of repellency of all test compounds followed the following pattern: O. gratissimum (3) > L. nobilis (3) > O. gratissimum (2) > O. gratissimum (1) > L. nobilis (1) > L. nobilis (2). All samples of both plant species showed high repellency class (IV-V). A contact toxicity bioassay on treated filter paper discs revealed differences between the respective oils from O. gratissimum 1, 2 and 3. Test solutions were prepared by dissolving essential oils in 1 ml acetone. The concentration ranged from 1 to 300 µlitre/ml. Acute adult mortality was determined after 3, 5 and 7 days of treatment. In experiments with concentrations of less than 10 µlitre/ml, mortality was not observed. Toxicity was positively correlated with the concentration up to 50-80 µlitre/ml and negatively correlated with concentrations of more than 80-100 µlitre/ml. At 60 µlitre/ml, 76 and 88% mortality were obtained within 7 days of application of the essential oils from O. gratissimum (1) and O. gratissimum (2), respectively. At 80-100 µlitre/ml, mortality of adult beetles did not increase further. The beetles released an odoriferous substance (quinone) from their defence glands. Weak insecticidal property was recorded for the other essential oil from O. gratissimum (3) and L. nobilis (2). Within 7 days, concentrations of less than 50 µlitre/ml did not result in insect mortality. The fecundity of the surviving insects was reduced. The composition of the essential oils significantly varied with the raw material from which the oil was obtained.
Effect of temperature and relative humidity on diatomaceous-earth-treated Callosobruchus maculatus (F.) and Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae).
Authors: Prasantha B. D. R. , Reichmuth C. , Büttner C. 
Published: November 2017

Abstract

Adults of C. maculatus and A. obtectus were exposed to mung bean and common bean (Phaseolus vulgaris) treated with the diatomaceous earth Fossil-Shield at 1020 and 1080 mg/kg, respectively. Diatomaceous-earth-treated bruchids were kept at 20, 25, 30 and 35°C with 43, 52, 64, 75 and 84% relative humidity, respectively. The mortality of C. maculatus and A. obtectus generally increased as the temperature increased but decreased with the increase in relative humidity. The variation between insect mortalities at 25 and 30°C under 52-75% relative humidity did not significantly vary. The interaction between temperature and relative humidity had little effect on the mortality of C. maculatus, but significantly affected the levels of control of A. obtectus. A. obtectus was less susceptible to Fossil-Shield than C. maculatus. Temperatures between 25 and 30°C are physiologically optimum for bruchids, but 35°C is close to the maximum tolerable temperature. At 20°C, most of the tropical and subtropical stored product insects show reduced activity, so the amount of lethal dust that comes in contact with insects becomes very small.
Insecticidal activity of some aromatic plants from Croatia against lesser grain borer (Rhyzopertha dominica F.) on stored wheat.
Authors: Kalinovíc I. , Rozman V. , Guberac V. , Maríc S. 
Published: November 2017

Abstract

Essential oils and plant dusts from the Croatian aromatic plants Lavandula officinalis [L. angustifolia] (dust from ground leaves, flowers and stems), Laurus nobilis (dust from ground leaves), Rosmarinus officinalis (dust from ground leaves and stems), and Thymus vulgaris (dust from ground leaves, flowers and stems) were evaluated for insecticidal activity against the lesser grain borer R. dominica infesting market and seed wheat under laboratory and storage conditions. Up to 100% mortality of adults was obtained over the exposure period. The efficacy of the plant material was compared to a control with no treatment. The rates of essential oils and plant dust recalculated on 5-kg wheat samples were 3.75 ml per sample of oils, and 37.5 g per sample of dust. In general, all essential oils exhibited strong insecticidal effect (100% mortality of adults after 24 h). L. nobilis was the most effective in dust form (100% mortality of adults after 7-10 days of exposure) under storage conditions. In the control samples, no mortality of adults was recorded. Over the 5-month period, damage on wheat was 30%, while insect population increased up to 190%. No changes in quality, colour or flavour of the commercial wheat flour were recorded during the treatment; however, each sample retained the scent of the plants tested. On seed wheat, no negative effect on germination or energy of germination was recorded. These aromatic plant products proved to be partial substitutes for synthetic insecticides if applied to smaller stocks of stored wheat.
Effect of the temperature during spraying on the biological efficiency of chemical protectants of stored grains.
Authors: Faroni L. R. D'A. , Guedes R. N. C. , Queiróz M. E. L. R. , Pimentel M. A. G. 
Published: November 2017

Abstract

The effects of high temperatures during application on pirimiphos-methyl persistence and efficacy against maize weevil (Sitophilus zeamais) were studied. Maize (cv. BR-1051) grains were sprayed with pirimiphos-methyl 500 EC (0.8 ml c.p./litre at 1.5 litre/t of maize) at different temperatures (25, 30, 35, 40, 45 and 50°C) and 55% relative humidity. The grains were then maintained at 27±1°C and 55±5% relative humidity for 90 days. Residues of pirimiphos-methyl on the sprayed grains were analysed every 30 days. Grain samples were evaluated every 15 days after insecticide spraying for their effect on maize weevil. Insect mortality was evaluated after 24 and 48 h of exposure to the treated grain. The level of pirimiphos-methyl residue on maize grains decreased with an increase in storage period and air temperature during insecticide spraying (varying from 11.0±0.1 to 1.1±0.1 ppm, corresponding to the residue levels at 25°C on the day of spraying and after spraying at 50°C and 90 days of storage). The same trend was observed for mortality of the maize weevil, which was reduced from 95.4±13.3% to 2.5±2.5% after 90 days storage after insecticide spraying at 50°C. These results indicate that temperature at spraying can affect insecticide persistence and activity during storage.
Microencapsulated formulations of chlorpyrifos as possible grain protectants.
Authors: Trostanetsky A. , Kostyukovsky M. , Carmi Y. , Frandji H. , Schneider R. 
Published: November 2017

Abstract

The efficacy of two new microencapsulated formulations of chlorpyrifos against Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Plodia interpunctella was studied under laboratory conditions. Master 25 and Master Quick at 10 and 20 ml/t were mixed with whole wheat grain as food. Master 25 resulted in the complete mortality of S. oryzae and T. castaneum adults at a concentration of 10 ml/t. A concentration of 20 ml/t was necessary to obtain 100% mortality in P. interpunctella larvae. Against R. dominica, Master 25 was not sufficiently effective at either rate. On the other hand, Master Quick resulted in 93 and 100% mortality of R. dominica adults at 10 and 20 ml/t, respectively, and 100% mortality of the other insects at 10 ml/t. Two months after treatment, the activity of Master 25 at 10 ml/t strongly decreased; at 20 ml/t, it was still highly active against S. oryzae, less active against T. castaneum and completely ineffective against R. dominica. On the other hand, Master Quick at 20 ml/t showed high activity against the insects, including R. dominica.