bluuebunny/crossref_metadata_2025 huggingface dataset:
Using new tools to track the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae).
Authors: Tigar B. , Waldron S.
Published: November 2017

We used natural markers to investigate dispersal by P. truncatus between rural stores and natural environments. Insects were collected in Mexico and Ghana using pheromone-baited flight traps, and from infested maize in Mexico. We applied three techniques to track the insects remotely: stable isotope analysis (SIA), to detect food use; molecular genetics, to reveal population mixing and relatedness; and trace-element profiling, to identify geographic origin. The δ13C signatures of candidate and known foods of P. truncatus were also determined. Foods were isotopically distinct, with δ13C signatures typical of either C4 or C3 plants (maize grains -11.6 per mil, Spondias purpurea -26.1 per mil), while δ13C and δ15N varied with region and habitat for P. truncatus. Rural stores in central western Mexico (Michuacán) were heavily infested, and P. truncatus δ13C signatures were consistent with maize consumption (mean δ13C -11.3 per mil) with one intermediate value, suggesting that natural areas were not reservoirs for infestations. Beetles from natural environments in Michuacán had a predominantly C4 δ13C signature (mean δ13C -11.5 per mil). This may indicate dispersal out of stores, or the use of field maize or other C4 foods. Ghanaian beetles from a teak forest were the most 13C-enriched (mean δ13C -9.3 per mil), indicating dependence on a C4 plant, though not necessarily maize. In northwestern Mexico (Sonora), beetles were highly 13C-depleted and had not consumed maize even when captured close to stores and field maize. In northern Mexico, the only beetle captured had a δ13C of -10.7 per mil (C4 plant) and the highest δ15N (-17.5 per mil). The δ15N was highly variable and will be discussed elsewhere. Genetic fingerprinting using amplified fragment length polymorphism suggested a high level of polymorphism in P. truncatus at local, regional, and national scales. Preliminary trace element profiling suggested that sulfur, chromium, and manganese were possible elements for tracking P. truncatus. We discussed future work and further development of the techniques for tracing dispersal.
Multiplication of stored-product mites on Canadian wheat and oilseed cultivars.
Authors: White N. D. G. , Demianyk C. J. , Jayas D. S.
Published: November 2017

Two experiments were conducted to determine the infestation potential of wheat and oilseeds to stored-product mites. In the first experiment, 10 adults of either Acarus siro or Acarus farris were placed into ventilated glass vials containing whole or crushed seed of 1-3 cultivars of each of wheat, sunflower, flax, soyabean, rape, and mustard. After 15 weeks incubation at 20°C and 75% RH, populations were assessed. All wheat cultivars, both whole and crushed, were highly susceptible to Acarus siro and barely susceptible to Acarus farris, indicating a strong difference in the reproductive requirements of the two closely related species. On wheat, mean multiplication rates for Acarus siro ranged from 11× to 296× on whole cultivars of Neepawa and Glenlea, respectively, and from 617× to 862× on crushed cultivars of Glenlea and Columbus, respectively. This indicates that the seed coat of whole seed provides marginal protection to feeding larvae. Acarus farris multiplied only 6× on whole Glenlea wheat, with all other treatments failing to sustain the original population. Acarus farris did poorly on all the cultivars of both whole and crushed oilseeds; the only population to increase above the original numbers was on whole Sundak sunflower, which had a mean increase of 2.5×. Similarly, Acarus siro did not reproduce on crushed oilseeds but showed an increase of 646× on whole Sundak sunflower, 114× on whole Domo mustard and 83× on whole Linott flax. A second experiment of similar design was conducted to determine the infestation rate on Columbus and Neepawa hard red spring wheat by the two Acarus species and three additional species of stored-product mites, Aeroglyphus robustus, Lepidoglyphus destructor, and Tyrophagus putrescentiae. Crushed seed of both cultivars sustained high populations of Acarus siro and T. putrescentiae, which increased 1059-1202× and 974-1963×, respectively. Lepidoglyphus destructor increased 147× on crushed Columbus but for the most part L. destructor, Aeroglyphus robustus and Acarus farris populations remained at low levels, increasing not more than 2-27× on whole and crushed seed of both cultivars. It appears that the stored-product mites tested here can all survive on whole stored cereals and oilseeds to varying degrees, but special consideration should be given to stocks that become infested with Acarus siro and T. putrescentiae. These two species take best advantage of damaged cereals, where nutrients are readily available, resulting in large population increases. Conversely, the crushing of oilseeds appears to inhibit mite propagation, probably because of excessive oil content (45%, dry weight) within the meal.
How to decide whether the presence of storage mites in food and feedstuffs actually matters.
Authors: Chambers J.
Published: November 2017

Many species of storage mite are found on various food products. This paper considers how to estimate the threats they pose to health. It reviews evidence for the exposure of humans and animals to mites in terms of their species, prevalence and abundance, and the different health effects they have been reported to cause. Mites have been found along the food-supply chain from farms to the home but the evidence is limited and cannot predict daily intake of mites or their source. Mites need to be considered as vectors of mycotoxins and pathogens, but there is insufficient information to establish the severity of this possible problem. Dermatitis has been reported after occupational exposure by surface contact with various mite-infested foods. Allergy to storage mites by inhalation is recorded in at least 7 countries after occupational exposure and is now being considered as a contributor to allergy in the home. Potentially severe consequences of mite allergy arise by ingestion, shown by five reports of anaphylactic reactions. Cooking did not destroy the allergens. In the most recent example, the level of mite infestation may have been very low, suggesting that the risk of clinical symptoms from ingesting mite infested food is higher than previously thought. There is evidence that mite infestation reduces the palatability of cattlefeed and the growth rate of pigs. A risk assessment to estimate the damage storage mites cause by these different effects would depend on imprecise estimates. Obtaining the information to establish safe thresholds for exposure to storage mite allergens would be difficult. The presence of mites in food is avoidable, so the best strategy must be to prevent infestation occurring. This approach is applicable to human food and animal feed and there is evidence that it works.
Occurrence of ochratoxin A in cereals and coffee in Hungary in 2001.
Authors: Fazekas B. , Tar A. K. , Zomborszky-Kovács M.
Published: November 2017

Ochratoxin A (OTA) is a carcinogenic and nephrotoxic secondary metabolite of several Aspergillus and Penicillium species. It forms during the storage of cereals and other products of plant origin. The aim of this work was to determine the ochratoxin content of foods and feeds posing a possible health hazard to humans and animals. One hundred and eight human foodstuff samples (baking wheat, wheat flour, maize coarse meal, roasted coffee) and 82 animal feedstuff samples (feeding wheat, feeding maize, feeding barley) were analysed by clean-up by immunoaffinity column followed by high-performance liquid chromatography (IAC-HPLC). Cereal samples were taken after 6-12 months of storage periods after harvest, and the roasted coffee samples were obtained from retailers. The limit of detection was 0.1 ng/g OTA. Of the wheat samples intended for human consumption, 8.3% tested positive for OTA, with levels ranging from 0.12 to 0.5 ng/g. The mean value of the positive samples was 0.29 ng/g OTA. The OTA levels in wheat flour and maize coarse meal samples were in a similarly low range. Ochratoxin A contamination was found in 66% of the roasted coffee samples. The highest and the mean levels of the positive samples were 1.3 ng/g and 0.57 ng/g, respectively. The proportion of feedstuff samples testing positive for OTA was 26.7%, 15.6% and 35% for feeding wheat, feeding maize and feeding barley, respectively. The mean values of positive samples and the OTA ranges, respectively, were: 12.2 ng/g and 0.3-62.8 ng/g for wheat; 4.9 ng/g and 1.9-8.3 ng/g for maize; and 72 ng/g and 0.14-212 ng/g for barley. Our results show that the OTA contamination of wheat intended for human consumption was very low, which can be explained by good weather conditions during the harvest and the use of adequate storage facilities. According to our calculations from the experimental data, the average daily OTA intake was only 6.7 ng from wheat and 4.1 ng from coffee. High contamination of feedstuffs raises the question of whether this poses a possible health hazard to animals, and increases the occurrence of OTA-contaminated animal-derived products. Since the relatively highly contaminated cereals were submitted by small animal holdings and feed-growing farms known to have obsolete storage facilities, our results emphasise the importance of good storage practices.
Impact of essential oils on growth and ochratoxin A production by Penicillium verrucosum and Aspergillus ochraceus on a wheat-based substrate.
Authors: Cairns V. , Magan N.
Published: November 2017

An in vitro initial screen of twenty-four essential oils for inhibition of spore germination and mycelial growth of mycotoxigenic strains of Penicillium verrucosum and Aspergillus ochraceus was made at 25°C and 0.99 water activity (aw). Based on a measurement of clearing zones, six essential oils were found to be effective in inhibiting growth: bay leaf (west Indian), cinnamon leaf, clove bud, clove leaf (cleaned), lemongrass and thyme. Based on those giving clearing zones greater than 5 mm, three were chosen for a more detailed study (clove leaf, cinnamon and bay leaf). The detailed screen was at 0-500 ppm on a 2% milled wheat agar modified to 0.99-0.90 aw for 56 days at 15°C and 25°C for isolates of both species. Generally, growth of the A. ochraceus and P. verrucosum was slower at 15°C than 25°C. Generally, regardless of temperature or aw there was significant (>90%) inhibition of growth with 500 ppm of these essential oils. However, at suboptimal concentrations, especially 50 ppm, some essential oils stimulated growth of both A. ochraceus and P. verrucosum by up to 10-15%. Analysis of the impact on ochratoxin A (OTA) production supported these findings. At 50 ppm there was stimulation of OTA production regardless of aw or temperature. However, at 500 ppm significant control of OTA production by A. ochraceus was observed with the best essential oil treatments. OTA production by P. verrucosum was completely inhibited at the maximum concentration and under the environmental conditions used.
Multitarget environmental approach for control of growth and toxin production by Fusarium culmorum using essential oils and antioxidants.
Authors: Hope R. , Jestoi M. , Magan N.
Published: November 2017

Twenty-three essential oils and six antioxidants were screened for control of growth of the mycotoxigenic species Fusarium culmorum. Of these, three essential oils (bay, clove and cinnamon oil) and two antioxidants (propyl paraben and hydroxymethylanisole) were found to be effective in controlling growth in the at concentrations of 50-200 ppm at 15°C and 25°C over the range 0.995 to 0.955 water activity (aw). More detailed studies were carried out to examine the efficacy of interactions between water activity aw (0.955, 0.995), temperature (15°C and 25°C) and these control treatments (100 ppm; 500 ppm) on growth and both deoxynivalenol and nivalenol mycotoxin production by F. culmorum on irradiated wheat grain. Higher concentrations of these control treatments (500 ppm) were needed to reduce or inhibit growth significantly on wheat grain when compared to that in vitro. Growth of F. culmorum was significantly affected by temperature, aw and antifungal treatment. At 100 ppm concentration the essential oils/antioxidants stimulated growth under some of the experimental conditions. Growth was significantly inhibited by 500 ppm concentration. Cinnamon and clove essential oils were the most effective inhibitors of growth regardless of temperature or aw level used. The control treatments had a variable effect on the production of mycotoxins by F. culmorum. Butylated hydroxy anisole and clove oil inhibited nivalenol and deoxynivalenol production at both 100 and 500 ppm concentration on wheat grain. However, propyl paraben and cinnamon oil enhanced nivalenol production at 100 ppm and intermediate aw levels.
Phosphine: an alternative for controlling fungal growth and to avoid mycotoxin production in high-moisture stored grains.
Authors: Castro M. F. P. M. de , Mills K. A.
Published: November 2017

Phosphine, a fumigant widely applied for insect control, may be an alternative for controlling fungi and mycotoxins in high-moisture stored grains. Published papers have demonstrated that the fumigation conditions for fungal control (concentration and exposure time) have to be established according to the type and moisture content of the grain as well as the species to be controlled. With respect to fungal control, recent studies with corn have shown that water activity (aw) is critical in determining the maximum "protective period", due to the growth of Fusarium verticilloides and yeasts and yeast-like fungi, which appear to be more tolerant to phosphine. The effect of phosphine on the production of mycotoxins has, so far, only been studied for aflatoxins in peanuts and corn grains, where very promising results were obtained. Studies on more toxigenic moulds and other mycotoxins are needed in order to fully evaluate the use of this technique to control fungi and to avoid production of mycotoxins in other commodity-mould interactions. Problematic situations exist where grains can be re-wetted by condensation during shipment or when grains with high m.c. are kept in storage for long periods prior to drying to a safe level. Phosphine can be carefully applied in order to guarantee the correct dosage in most situations. These include in-transit fumigation in good gastight and pressure-tested freight containers; bagged commodities in well-sealed and vacuum-tested sacks; and bulked grains in bins, silos or floor stores, with positive pressure systems or recirculation of the atmosphere. Conventional phosphide formulations or cylinderised formulations can be used as appropriate.
Is Kashin-Beck disease related to the presence of fungi on grains?
Authors: Chasseur C. , Begaux F. , Suetens C. , Mathieu F. , Nolard N. , Malaisse F. , Wang Z. , Haubruge E.
Published: November 2017

Kashin-Beck disease (KBD) is an endemic osteochondropathy that affects primarily children in Asia. More than 30 million people living in endemic areas are at direct risk of developing KBD, and approximately 2 million people are affected in China alone. Its unknown aetiology represents a continuing challenge to agroenvironmental and medical sciences. Currently, severe contamination of cereals by mycotoxin-producing fungi has been proposed as one of the major environmental causes of the disease. Mycotoxins are naturally occurring toxic chemical compounds produced by fungi infesting agricultural crops during both crop growth and storage. Such secondary metabolites, when ingested, can produce toxic syndromes in humans. Since it has been hypothesised that the presence of fungi on barley grains might be involved in the development of KBD, we have undertaken a survey of barley and wheat grain of KBD-affected and non-affected families in the Autonomous Region of Tibet and in Shaanxi Province (China).
Ochratoxin A in wine: importance of preharvest factors in the spread of ochratoxin-producing fungi and on toxin accumulation in grapes.
Authors: Battilani P. , Pietri A. , Giorni P. , Kozakiewicz Z. , Logrieco A.
Published: November 2017

Ochratoxin A (OTA) in grapes and their processed products is a significant postharvest problem. However, it is also important to assess the role that preharvest factors play in this problem. Field trials were conducted in Italy in 1999 and 2000 aimed at identifying fungi responsible for OTA production in grapes and investigating how and when these fungi are able to produce OTA. During the two-year survey many isolates belonging to the genera Aspergillus and Penicillium were obtained; the majority (95%) were identified as Aspergillus section Nigri. Isolates were attributed to two groupings according to their morphology: uniseriate or biseriate conidial heads, with A. carbonarius being identified to species level within the biseriate grouping. All the isolates were tested for OTA production in vitro. Aspergillus carbonarius proved to be the most toxigenic with 60% of strains producing OTA; other species within section Nigri were only 3-5% OTA positive. Aspergilli and penicillia were present on grapes starting at setting, but from early veraison (colour change) their frequency increased significantly. Only in 1999 was OTA detected in grape bunches in significant amounts at early veraison in few vineyards in the south of the country, with increasing amounts at ripening. Cultural factors investigated did not show a clear role in determining OTA content in grapes, the most significant factors being the year (rainfall) and the geographic region. According to these results, which concur with other authors, Aspergillus section Nigri, and in particular A. carbonarius, play the main role in OTA production, but factors influencing their metabolism are not yet defined. Further research is needed on factors influencing growth of OTA-producing fungi and OTA synthesis in grapes. A European Union project was started in 2001 to assess the risk of OTA to consumers of grapes and wine produced Europe. Its aims are to reduce the amount of toxin present with the aid of an integrated management system for production and processing.
Slow generation of phosphine using QuickPHlo-CTM technology.
Authors: Waterford C. J. , Asher P. P.
Published: November 2017

A slow-release generator, QuickPHlo-CTM, developed to provide a controlled rate of phosphine production, was tested at 10 g/h. This rate was maintained up to 16 days, supplying a relatively constant flow of fumigant in air, to service active fumigation techniques such as SIROFLO. Results of a controlled, phosphine-generation trial are presented. The generator consists of a reactor and related accessories for controlled on-site production of phosphine. Phosphine is produced by the action of water sprayed onto specially formulated blocks of aluminium phosphide and paraffin wax, sized to produce average rates of 5, 10 and 20 g/h phosphine over 16 days. Air is drawn through the reactor to safely displace the generated phosphine into the storage and maintain a uniform effective concentration throughout the fumigation. Safety systems to handle power failure and safe shutdown were tested and are described in this paper.
Ecologically friendly methods used in Cyprus for grain storage and protection (a combination of hermetic storage, aeration and fumigation using phosphine from cylinders and in sleeves).
Authors: Varnava A.
Published: November 2017

Experience in Cyprus shows that the use of storage structures such as hermetic bins, bunkers and platforms, in combination with fumigation systems (such as SIROFLO using phosphine gas from cylinders, or fumigation with phosphine in the form of strips, sleeves or crushed tablets), followed by aeration to remove chemical residues, is a successful means for safe, ecologically friendly protection of grain during storage. The aeration of grain in bins is an important way to protect grain quality, minimizing the need for insecticides. The new technology of aeration of grain in bunkers may solve condensation problems and increase the permissible initial moisture content of grain for bunker storage. The storage of grain in bunkers is a low-cost way to rapidly increase the storage capacity of many countries. The above methods of storage and grain protection minimize the need to use liquid insecticides or methyl bromide and they have ecological advantages.
Insect control of cocoa pests using a novel vacuum approach.
Authors: Finkelman S. , Navarro S. , Lotan Y. , Debruin T. , Isikber A. A. , Rindner M. , Dias R. , Azrieli A.
Published: November 2017

Two field trials were carried out using 24 tonnes of cocoa beans to evaluate the feasibility of storage and pest control under low pressure using a novel approach on the application of vacuum technology. In these field trials, a new transportable, flexible storage system of 15-m3 capacity termed the Volcani Cube or GrainPro Cocoon, and a rotary oil-lubricated vacuum pump were used. A preliminary trial was conducted in March 2001 in Israel, at the Agricultural Research Organization (ARO) campus using 2 Volcani cubes to evaluate the vacuum system performance ahead of the demonstration trial. Here we report on the demonstration field trial performed for Nestlé. It was conducted using 2 cubes in November 2001 at Abidjan, Cote d'Ivoire. The pressure in the cubes was maintained within the range of 25 and 50 mm Hg for durations of 3 and 7 days. Each cube contained 87 jute bags, each weighing 65 kg (total 5650 kg per cube). All life stages of Ephestia cautella [Cadra cautella], Plodia interpunctella and Tribolium castaneum were used as bioassay test insects. Caged insects were placed in the cubes before the start of the trial. Complete mortality of all life stages of all species was obtained in all 4 cubes. These results showed that the use of low pressure for controlling storage insect pests is feasible without the need for the large, rigid chambers employed in conventional vacuum-fumigation facilities today.
Physiological aspects of diatomaceous-earth-treated cowpea weevil Callosobruchus maculatus (F.) (Coleoptera: Bruchidae).
Authors: Prasantha B. D. R. , Reichmuth C. , Hetz S. K. , Adler C.
Published: November 2017

Investigations were carried out on the effects of a diatomaceous earth (DE) treatment on the physiology of the cowpea weevil C. maculatus. Adult female cowpea weevils were treated with DE at 25°C and 40, 75 or 99.9% relative humidity to determine the changes in body water content and cuticular water permeability. A twin differential microcalorimeter was used to determine the average energy production. Carbon dioxide release of single C. maculatus was recorded in a flow-through respirometer at 25°C. The highest body water loss rate occurred at 40% relative humidity. Even at 99.9% relative humidity, DE-treated insects continuously lost body water until they died after loosing 46% of their body water. Microcalorimetric studies revealed that metabolic heat production rates in DE-treated cowpea weevils were significantly higher than in untreated insects. Predominately at 25°C ambient temperature, the DE-treated insects showed different respiratory patterns compared with untreated insects. The carbon dioxide release in untreated animals was more or less discontinuous, whereas in treated set ups, it occurred almost continuously. It is argued that the death of DE-treated cowpea weevils could be the result of high water loss together with stress-related high physiological metabolic activity.
Optimisation of inert dusts used as grain protectants and residual surface treatments.
Authors: Arthur F. H.
Published: November 2017

Inert dusts such as diatomaceous earth (DE) are being advocated as natural control methods to eliminate insect infestations in stored grain, milling and processing plants, and food storage areas. However, efficacy of DE can be highly variable, depending upon the product, insect species, life stages used in tests, methods of exposure, environmental conditions, and presence of food material. It is important to identify these sources of variation so that controlled laboratory studies are relevant to field applications. In this paper, examples are used to illustrate concepts and ideas for inert dusts used as grain protectants and as residual surface treatments in indoor areas. New research approaches will also be discussed, in which inert dusts are used in combination with other insecticides to control stored product insects.
Models linking insecticidal efficacy decline and residue concentration decrease with time, temperature and water activity in chlorpyrifos-methyl treated wheat.
Authors: Fleurat-Lessard F. , Wilbert T. , Vidal M. L.
Published: November 2017

Contact insecticide admixture with stored grain is widely used in France to give long-term protection of stored cereals. Among the range of registered insecticides, organophosphates such as chlorpyrifos-methyl (CPM) are commonly used. To predict the level of CPM residues at any time within the storage period, changes in CPM residue content and their efficacy against the most harmful species (Sitophilus granarius and Tribolium castaneum) during storage time were investigated. Wheat conditioned at two different moisture contents (corresponding to water activities (Aw) of 0.7 and 0.8 in grain) was treated at 2 mg/kg CPM, then stored at constant and controlled conditions of relative humidity (at equilibrium with Aw) and temperature. Subsamples of treated grain were stored at 15, 22.5 and 30°C. During a 20-week storage period, measurements of CPM residue content and residual efficacy were carried out every 3 weeks. Models of degradation were produced over the Aw range 0.7-0.8 and at the three temperature levels of the experimental design. With these models, the half-life of residues was accurately predicted. A generalized model was then developed through a multivariate linear regression with the three measurable variables: storage time, temperature and Aw. Bioassays were performed on the two target insect species to assess the decline in efficacy of residues. The length of the period with no insect survival and the storage time when the point of 50% survival is observed (for each species) were also assessed. A more rapid decline of efficacy of CPM residues with T. castaneum than with S. granarius was observed. The limit for 50% mortality of T. castaneum in the different storage conditions was observed in the same range of the half-life of CPM residues.
A survey of psocid species infesting stored grain in China and resistance to phosphine in field populations of Liposcelis entomophila (Enderlein) (Psocoptera: Liposcelididae).
Authors: Cao Yang Cao Yang , Song Yi Song Yi , Sun GuanYing Sun GuanYing
Published: November 2017

A survey of the distribution of psocids in major grain storage systems in various provinces of China (Jilin, Liaoning, Gansu, Shanxi, Beijing, Hebei, Henan, Shandong, Anhui, Jiangsu, Zhejiang, Jiangxi, Fujian, Sichuan, Yunnan, Guizhou, Hunan, Guangdong and Guangxi) was conducted. L. entomophila was the most common and widely distributed, followed by L. decolor. L. paeta and Liposcelis mendax were also detected. Ten strains of L. entomophila were evaluated for resistance to phosphine. All strains showed resistance compared with a susceptible reference strain, with resistant factors ranging from 40- to 80-fold. Resistance to phosphine appears to be the major factor determining psocid infestation in grain storage facilities in China.
Diatomaceous earth structural treatment against Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) under fluctuating UK conditions.
Authors: Cook D. A. , Collins L. E. , Armitage D. M.
Published: November 2017

The first UK trial to evaluate diatomaceous earth (DE) structural treatment was carried out during February 2002. A bin containing 20 t of "heating" insect-infested wheat resulted in migration of large numbers of O. surinamensis into the storage structure and surrounding area. The DE "Silico-Sec" was applied at approximately 10 g/m2 to the outsides, undersides and concrete floor beneath a nest of six, galvanized steel 3×3×4 m bins. Hand-operated, electric and gas-powered dusters were compared for ease of treatment. I-SPy Insect Indicators, incorporating multi-species lures, were placed before and after treatment. The number of insects trapped from an initial average of 406 per trap was reduced by 86-100%. Before treatment, a sample of the population was used to set up bioassays in petri dishes containing 100 insects each. Paired bioassays, one uncovered and one closed, were designated as treated and untreated controls. The mean mortality increased from 52% at 7 days to 99% after 14 days and 100% after 21 days. The mean temperature for this period was 6°C with the relative humidity at 80%. The low temperature and high humidity allowed testing under the most challenging environmental conditions for the DE dust. Photographed tracks gave an indication of insect movement after treatment. The electric-powered duster proved too powerful for the treatment of the steel structure, blowing away the dust that had been applied. The hand-operated model was very flexible and the speed of the treatment could be easily adjusted. The smaller, gas-powered applicator was well-suited for the treatment of small areas.
The efficacy of flufenoxuron, azadirachtin and a diatomaceous earth, when admixed with oilseed rape, against storage mite pests.
Authors: Collins D. A.
Published: November 2017

The efficacy of three compounds that might prove suitable alternatives to organophosphorus compounds (OP) were evaluated, when admixed with oilseed rape (cv. Capricorn), against mixed stages of OP-susceptible strains of Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae at 15°C and 80% relative humidity. The treatments consisted of flufenoxuron at 0.25, 0.5, 1 and 2 mg/kg; azadirachtin at 20, 40, 60 and 80 mg/kg; and Protect-It (diatomaceous earth) at 0.5, 1, 3 and 5 g/kg. Population inhibition was evaluated after at least one generation. Protect-It appeared to be the most effective treatment against all the mite species, with 3 g/kg inhibiting the populations by >96%. Flufenoxuron was highly effective at all rates against L. destructor, resulting in >90% inhibition. Azadirachtin appeared to be the least effective against all the species, recording an inhibition of 66-80% at the highest rate.
The use of a propane burner to control an artificially induced "hotspot".
Authors: Conyers S. T. , Llewellin B. E. , Cook D. A. , Bell C. H.
Published: November 2017

An artificial hotspot was induced in a floor store of grain by introducing 36 kg of wheat grains infested with 4200/kg of all the stages of Oryzaephilus surinamensis, and 13 000/kg of adult and 4800/kg of developing Sitophilus granarius. The insects were left for four weeks to allow their populations to develop. Population numbers were monitored by trapping on and below the surface of the grain and by grain sampling. Five days before treatment commenced, trap counts at 1 m depth at the hotspot gave 6825 juveniles and 267 adults of O. surinamensis, and 245 adults of S. granarius. Grain samples collected within 0.5 m of the hotspot three days before treatment started ranged from 128 to 574 adults/kg for O. surinamensis, and from 382 to 505 adults/kg for S. granarius. The development of the hotspot was also monitored by static thermocouples within the grain. These showed a steady rise in temperature. Ambient temperature during the period did not exceed 8°C, and the grain bulk had a mean of 6°C at 0.5 m and 11°C at 1.0 m depth. After four weeks, the hotspot reached 38°C and an average of 31.5°C, 0.5 m away at 1.0 m depth. An exothermic inert atmosphere generator was used to treat the hotspot for a two-week period. It produced a modified atmosphere (MA) of 0.6% oxygen (O2) and 13% carbon dioxide. The output of 200 litre/minute from the generator was passed to the site by plastic pipe with a loop at the end that surrounded the hotspot. Lengths of pipe pushed down into the grain were used to introduce the atmosphere under the hotspot. The area was then covered by a 7 m2 plastic sheet. The input flow maintained an O2 level between 0.2 and 0.9% at all points in the hotspot. The O2 readings below those of the output were probably caused by microbial activity. On starting the flow, there was an immediate drop in temperature in the treated area. The core of the hotspot dropped to 17°C by the end of the treatment. Grain samples and trap collections were made at the end of the trial and continued for two months. No survivors were found by either method. Therefore, MA resulted in the complete control of the insect populations with no sign of any dispersal in the bulk due to the treatment.
Disinfestation of rust-red flour beetle (Tribolium castaneum), saw-toothed grain beetle (Oryzaephilus surinamensis), yellow meal worm (Tenebrio molitor), Mediterranean flour moth (Ephestia kuehniella) and Indian meal moth (Plodia interpunctella) with sulfuryl fluoride in flour mills.
Authors: Reichmuth C. , Rassmann W. , Binker G. , Fröba G. , Drinkall M. J.
Published: November 2017

Fumigations with sulfuryl fluoride were conducted in flour mills in Germany in July 1998 and 1999, and April 2000 with sulfuryl fluoride (tradename ProFame) to evaluate the effectiveness of the fumigant under practical conditions. Bioassays of all life stages of the stored product insects E. kuehniella, P. interpunctella, Tribolium castaneum, Tenebrio molitor and Oryzaephilus surinamensis were introduced into the mills before fumigation. Sealing was achieved using tape and polyethylene in two mills and in the third by covering with tarpaulins to achieve effective gastight enclosures. The mills were heated as part of the fumigation procedure using either coil-in-oil electric heaters or ducted hot air generated by external oil burners. The temperatures and relative humidities recorded at the bioassay locations ranged from 22 to 40°C and 20 to 80%, respectively. The fumigation periods (exposure times) were approximately 36 or 48 h with rates (concentration × time products) between 1860 and 2255 g h-1 m-3. A very high level of mortality of all species and life stages was obtained, confirming that sulfuryl fluoride is effective for the disinfestation of flour mills under practical conditions.
Rapid generation of phosphine using QuickPhlo-RTM technology.
Authors: Asher P. P. , Waterford C. J.
Published: November 2017

Results are presented of trials of equipment designed to use a new formulation of aluminium phosphide, QuickPHlo-RTM, for phosphine generation. A quick-release generator that delivers up to 6 kg of phosphine per hour to rapidly establish an effective concentration in sealed storage has been tested. The equipment consists of a reactor and related accessories for controlled on-site generation of phosphine. Air is recirculated to safely displace the generated phosphine into the storage and attain a uniform effective concentration in a short time. The system does not leave solid residues in grains. It is easy to apply, uses less labour and the equipment is 'user friendly'. The technique is suitable for fumigation of all types of sealed storages and structures.
Towards more effective heat disinfestation from a biological perspective.
Authors: Beckett S. J.
Published: November 2017

This paper discusses heat tolerance during the development of stored product insects, impact of environmental moisture on insect survival, and impact of the rate of heating on mortality. The development of statistical models and the importance of monitoring the effects of treatment on product quality are also discussed.
Heat disinfestation of empty farm silos before inloading.
Authors: Beckett S. J. , Qaisrani R.
Published: November 2017

The efficacy of heat treatment for the control of adult populations of Tribolium castaneum and mixed-age populations of Rhyzopertha dominica at an experimental 50-tonne silo was evaluated. Heating was conducted with a 54-kW electric heater with an 11-kW radial fan with a speed regulator to pump the hot air into the silo, or with a more powerful heating system consisting of electric liquid petroleum gas burner with a 15-kW axial flow fan. Populations of T. castaneum were completely destroyed by the time a target air temperature of 54°C was reached (10 minutes). Grain temperatures of 53.4 and 55.2°C for periods of 4 and 3 h, respectively, resulted in a mortality of up to 99.99% in the most tolerant developmental stage of R. dominica. Complete mortality was obtained by the time a grain temperature of 60.6°C was reached at all but one location. An alternative method of heating resulted in complete mortality at 61.8°C. Heat disinfestation will be most effectively and economically achieved by using high inlet temperatures to produce rapid heating to a temperature where complete mortality is guaranteed by the time that temperature is reached. The energy cost of such a treatment could be less than $A1.00 (US$0.58).
Effect of organophosphates on Acarophenax lacunatus (Prostigmata: Acarophenacidae) parasitising Rhyzopertha dominica (Coleoptera: Bostrichidae).
Authors: Faroni L. R. D'A. , Guedes R. N. C. , Gonçalves J. R. , Zanuncio J. C.
Published: November 2017

The interaction between the organophosphate insecticides fenitrothion and pirimiphos-methyl with A. lacunatus, an egg parasite of the stored grain pest R. dominica, was evaluated. Petri dishes containing 25 g of whole wheat grains (13% moisture content) were treated with insecticides (0.9, 1.8, 2.5, 5.0 or 10.0 ppm for fenitrothion, and 0.5, 1.0, 2.0, 3.0, 4.0 or 8.0 ppm for pirimiphos-methyl) and infested with 25 adults of R. dominica. Seven days after insect infestation, mites were released at different densities per experimental unit. The number of physogastric females of A. lacunatus and egg parasitism increased with the decrease in insecticide rate and increase in mite density for both organophosphates. Lower insecticide rates for and mite densities resulted in higher instantaneous rates of increase in mite population. In general, lower instantaneous rates of increase in A. lacunatus population were obtained with pirimiphos-methyl. The sustained presence of the mite species at all insecticide rates suggests that this biological control agent may be used together with insecticidal applications for controlling R. dominica, although higher insecticide rates, especially of pirimiphos-methyl, retard the growth of the mite population.
Investigation of the use of ozone fumigation to control several species of stored grain insects.
Authors: Qin ZhangGui Qin ZhangGui , Wu Xia Wu Xia , Deng Gang Deng Gang , Yan XiaoPing Yan XiaoPing , He XueChao He XueChao , Xi DeKe Xi DeKe , Liao XingWen Liao XingWen
Published: November 2017

The efficacy of ozone as a fumigant was evaluated against various primary grain insects under laboratory conditions. Ozone was effective for the control of phosphine-susceptible strains of Sitophilus zeamais, Rhyzopertha dominica and Tribolium castaneum, and phosphine-resistant strains of S. oryzae, R. dominica, and T. castaneum on rice, wheat and maize. Ozone killed all the adults of the evaluated species in 2 days at 120 ppm, in 4-6 days at 100 ppm, in 6-7 days at 70 ppm and in 12 days at 15-20 ppm. Similar results were obtained in an experiment conducted in maize and rice warehouses at Sichuan province, China. Ozone appears to have some potential for use in controlling insects in stored products.
Effects of ultrasound on Indian meal moth reproduction.
Authors: Huang F. N. , Subramanyam B.
Published: November 2017

The effects of ultrasound emitted from a commercial ultrasonic device (Cix 0600) and a novel unit developed at Kansas State University (KSU) on the reproduction of Indianmeal moth, Plodia interpunctella, were evaluated in paired Plexiglas enclosures. The commercial ultrasonic device generated peak frequencies at 21, 25 and 35 kHz, and a 94-dB sound pressure level at a distance of 50 cm. The KSU unit produced frequency, pulse duration and quiet time at random. Ultrasound emitted from both of the ultrasonic units had a similar and significant impact on the number of spermatophores transferred by males to females, the number of larvae produced, larval weight and adult distribution within enclosures. In the presence of ultrasound, each female, on average, had 1.5 spermatophores. In the absence of ultrasound, each female had 2 spermatophores. Larval numbers were reduced by 48 and 38% when moths were exposed to ultrasound produced by the Cix 0600 device and KSU unit, respectively. Therefore, the total larval biomass in the enclosures with ultrasound was significantly less than that in the enclosures without ultrasound. The distribution of larvae within enclosures was affected by ultrasound emitted by the Cix 0600 device but not by the KSU unit. Higher number of P. interpunctella moths were found on the enclosure floor in the presence of ultrasound than without ultrasound. These data suggest that use of ultrasound technology could be exploited for the management of P. interpunctella reproductive behaviours.
Control of mites in stored grain and oilseeds using phosphine.
Authors: Watson C. R. , Wilkin D. R. , Clayton-Bailey I.
Published: November 2017

Results are presented of laboratory and field experiments that evaluated the efficacy of phosphine against mites infesting stored grain and oilseed products in the UK. Mite control by fumigation is discussed.
Study on the effects of mixtures of acetone extracts of black pepper (Piper nigrum L.) and nutmeg (Myristica fragrans Houtt) seeds on the development of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae).
Authors: Haryadi Y. , Rahayu S.
Published: November 2017

Mixtures of acetone extracts from black pepper (P. nigrum) and nutmeg (M. fragrans) seeds were evaluated under laboratory conditions for their insecticidal effect on maize weevil (S. zeamais) reared on maize kernels. Mixtures of 0.0, 0.1 and 0.2% (v/w) of black pepper extract and 0.0, 1.0, and 2.0% (v/w) of nutmeg extract were incorporated into the diet to obtain nine mixture combinations. The number of F1 progenies and the developmental period were observed, and a developmental index was obtained based on these data. The presence of the extracts in the diet significantly reduced the number of F1 offsprings, prolonged the developmental period and reduced the developmental index. Progenies were still recorded for the diet with a combination of 2.0% nutmeg extract and 0.0% black pepper extract, but progenies were not recorded for all the five replicates. In all other combinations with both black pepper and nutmeg extracts, the presence of progenies was not observed. The results suggest that mixtures of acetone extracts of black pepper and nutmeg seeds have significant effects on the development of S. zeamais, and that the acetone extract of black pepper has relatively better insecticidal properties than the nutmeg extract.
Fungi control by phosphine fumigation in high-moisture maize.
Authors: Castro M. F. P. M. , Leitão M. F. F. , Oliveira J. J. do V. , Mills K. A.
Published: November 2017

Control of fungal growth by phosphine was studied in maize stored with high moisture contents. In addition to the natural microflora of the grains, the product was inoculated with an Aspergillus flavus toxigenic strain. Surface response methodology was used in order to assess the various effects of phosphine on fungal growth in the grains, at water activities from 0.85 to 0.98 (equivalent to 16.0% and 24.5% m.c., w.b.), phosphine concentrations from 0 to 4 g/m3 and exposure periods from 1 to 15 days to the fumigant. The control of fungal growth was evaluated by direct plating of the grains, the serial dilution technique and the ergosterol content. Analyses of m.c., water activity and aflatoxins were also carried out on the samples subjected to the different treatments. Phosphine concentrations were measured by gas chromatography. An analysis of the results showed that, in general, the phosphine concentration was more important than the exposure period to the fumigant for fungal control. At water activities higher than 0.92, grains should not be kept for periods longer than about seven days due to the growth of Fusarium verticillioides (a potential fumonisin producer) and yeast and yeast-like moulds which seemed to be more tolerant to this fumigant. Aflatoxins were not detected in the fumigated samples. It was concluded that phosphine can control fungal growth and the production of aflatoxins and could thus be applied to grains while they are waiting to be properly dried or rewetted during storage or transportation.
A two-dimensional model of grain storage with dynamic visualisation: predictions for temperature, moisture content, germination and respiration - a case study for rapeseed.
Authors: Xanthopoulos G. , Woods J. L.
Published: November 2017

The development of a two-dimensional (r-z plane) simulation model of a cylindrical silo is described. The model assumes the presence of axi-symmetric conditions. The heat and mass transfer equations are solved for the case of uniform vertical flow using the "up-wind" difference technique employed in computational fluid dynamics. This describes the ventilated case and the unventilated case, when the velocity is set to zero, and the heat and mass transfer is assumed to be driven purely by diffusion. For the ventilated case, aerodynamic dispersion terms are incorporated, describing the enhancement of heat and moisture diffusion by mixing of air in its tortuous path through the grains. The programme can simulate the storage of wheat, barley and rapeseed using subroutines for each set of properties. The solution of the energy and moisture balance equations provides the temperature and moisture fields over a vertical section through the silo axis. Subroutines to predict germination (viability) and respiration (mould growth) are then used to calculate the percentage viability and cumulative dry matter loss. Using contour-mapping software, the temperature, moisture content, viability and cumulative dry matter loss are displayed in two dimensions. The programme was used to investigate the holding of high-moisture rapeseed before drying, with air flows of 0, 5, 10 and 15 m3 h-1 t-1. With no ventilation, the grain temperature increased rapidly to 50°C in approximately 12 days. On the other hand, even the lowest ventilation rate was sufficient to maintain the grain temperature to approximately 20°C. During ventilation, the mean moisture content dropped to 12.8% at approximately 30 days regardless of the flow rate. The cumulative dry matter loss was significantly reduced by ventilation.