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Toxicity of fine powders, filter cake and Triplex against Sitophilus zeamais adults: Presentation
No full textFilter cake and Triplex are powdered by-products of aluminum sulfate and soap factories, respectively. There is limited data about the use of these powders as grain protectants. This study was aimed at determining contact toxicity of both powders against Sitophilus zeamais, a common pest of stored grains. Lethal concentration of both powders to S. zeamais was determined by exposing 10 adults for 12 h in 9 cm diameter concrete arenas inside Petri dishes dusted with filter cake (0 - 8 g/m2) or Triplex (0 - 9 g/m2). Lethal time was determined by exposing adults to 3 g/m2 filter cake and 9 g/m2 Triplex for 1 to 24 h. Each treatment was replicated 3 times. At the intended exposure time, adults were transferred to 150-ml round plastic containers with 30 g of wheat and held at 28 degree Celsius and 65% r.h. for 14 d to determine mortality. Adult progeny production was determined after 42 d. A 50% mortality of adults was obtained at 0.61 g/m2 of filter cake and 1.61 g/m2 of Triplex concentrations with a 12 h exposure. The corresponding effective concentrations for 50% reduction of progeny production were 0.18 g/m2 of filter cake and 2.66 g/m2 of Triplex. Lethal times for 50% mortality of adults after exposure to 3 g/m2 of filter cake and 9 g/m2 of Triplex were 4.42 and 4.29 h, respectively. The corresponding effective times for 50% reduction of progeny production after exposure to 3 g/m2 of filter cake and 9 g/m2 of Triplex were 1.74 and 2.34 h respectively. The overall result indicated that filter cake was highly toxic to S. zeamais than Triplex. Therefore, filter cake is a potential powder to be included in the integrated pest management practice in small holder farmers’ storage structures after tested under real field conditions.Filter cake and Triplex are powdered by-products of aluminum sulfate and soap factories, respectively. There is limited data about the use of these powders as grain protectants. This study was aimed at determining contact toxicity of both powders against Sitophilus zeamais, a common pest of stored grains. Lethal concentration of both powders to S. zeamais was determined by exposing 10 adults for 12 h in 9 cm diameter concrete arenas inside Petri dishes dusted with filter cake (0 - 8 g/m2) or Triplex (0 - 9 g/m2). Lethal time was determined by exposing adults to 3 g/m2 filter cake and 9 g/m2 Triplex for 1 to 24 h. Each treatment was replicated 3 times. At the intended exposure time, adults were transferred to 150-ml round plastic containers with 30 g of wheat and held at 28 degree Celsius and 65% r.h. for 14 d to determine mortality. Adult progeny production was determined after 42 d. A 50% mortality of adults was obtained at 0.61 g/m2 of filter cake and 1.61 g/m2 of Triplex concentrations with a 12 h exposure. The corresponding effective concentrations for 50% reduction of progeny production were 0.18 g/m2 of filter cake and 2.66 g/m2 of Triplex. Lethal times for 50% mortality of adults after exposure to 3 g/m2 of filter cake and 9 g/m2 of Triplex were 4.42 and 4.29 h, respectively. The corresponding effective times for 50% reduction of progeny production after exposure to 3 g/m2 of filter cake and 9 g/m2 of Triplex were 1.74 and 2.34 h respectively. The overall result indicated that filter cake was highly toxic to S. zeamais than Triplex. Therefore, filter cake is a potential powder to be included in the integrated pest management practice in small holder farmers’ storage structures after tested under real field conditions
The effectiveness of Spinetoram against red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae): Poster
No full textTechnical improvement of the Detia Degesch Phosphine Tolerance Test Kit: Presentation
Get PDFPhosphine is the most important commonly used fumigant for the control of stored product insects in warehouses and processing facilities globally. However, the improper and extensive use has led to reduced susceptibility to phosphine for several insect species and strains in many parts of the world. To evaluate and quantify this phenomenon, Detia Degesch developed the Detia Degesch Phosphine Tolerance Test Kit (DDPTTK) more than 10 years ago. The use of DDPTTK is based on the exposure of the insects on a high concentration of phosphine (e.g. 3000 ppm) for short exposure periods (e.g. 8-15 min). This kit can be used on site by the fumigation and food industry, and can provide immediate results on the tolerance status of the insect strains that are to be treated. So far, the instructions of DDPTTK refer only to a six insect species. In this work, data for the expansion of knowledge about other species is provided, in order to broaden the spectrum of cases where the kit can be used. Moreover, certain improvements for the use of the kit are introduced, i.e. practical recommendations on the procedure and safety instructions.Phosphine is the most important commonly used fumigant for the control of stored product insects in warehouses and processing facilities globally. However, the improper and extensive use has led to reduced susceptibility to phosphine for several insect species and strains in many parts of the world. To evaluate and quantify this phenomenon, Detia Degesch developed the Detia Degesch Phosphine Tolerance Test Kit (DDPTTK) more than 10 years ago. The use of DDPTTK is based on the exposure of the insects on a high concentration of phosphine (e.g. 3000 ppm) for short exposure periods (e.g. 8-15 min). This kit can be used on site by the fumigation and food industry, and can provide immediate results on the tolerance status of the insect strains that are to be treated. So far, the instructions of DDPTTK refer only to a six insect species. In this work, data for the expansion of knowledge about other species is provided, in order to broaden the spectrum of cases where the kit can be used. Moreover, certain improvements for the use of the kit are introduced, i.e. practical recommendations on the procedure and safety instructions
Evaluation of tolerance/resistance to phosphine of stored product beetle populations from Europe, by using different diagnostic methods: Presentation
Get PDFWe evaluated the susceptibility to phosphine in different populations originated from 14 European countries, by following different diagnostic protocols. In total, more than 200 populations were screened during these tests, classified to 9 beetle species: Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Lasioderma serricorne (F.) (Coleoprtera: Anobiidae). The different bioassay-related diagnostic protocols that were followed were based on different exposure intervals and phosphine concentrations, ranging between 90 min and 4 d, and between 30 and 3000 ppm, respectively. Our results indicated that one of the populations that had been sampled from Europe was strongly resistant to phosphine. Moreover, the different protocols provide comparable results, which means that a standardized diagnostic can be further designed and adopted. Moreover, molecular assays indicated that the mutations P49S in R. dominica and P45S in T. castaneum are common among different populations, regardless of the degree of resistance to phosphine. Our results suggest that there are reliable quick tools for the evaluation of resistance to phosphine and that insect sampling in target areas should be conducted on a regular basis.We evaluated the susceptibility to phosphine in different populations originated from 14 European countries, by following different diagnostic protocols. In total, more than 200 populations were screened during these tests, classified to 9 beetle species: Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Lasioderma serricorne (F.) (Coleoprtera: Anobiidae). The different bioassay-related diagnostic protocols that were followed were based on different exposure intervals and phosphine concentrations, ranging between 90 min and 4 d, and between 30 and 3000 ppm, respectively. Our results indicated that one of the populations that had been sampled from Europe was strongly resistant to phosphine. Moreover, the different protocols provide comparable results, which means that a standardized diagnostic can be further designed and adopted. Moreover, molecular assays indicated that the mutations P49S in R. dominica and P45S in T. castaneum are common among different populations, regardless of the degree of resistance to phosphine. Our results suggest that there are reliable quick tools for the evaluation of resistance to phosphine and that insect sampling in target areas should be conducted on a regular basis
Screening of phosphine resistance in Sitophilus oryzae (L.) (rice weevil) populations in Turkey: Presentation
No full textIn this study, the status and prevalence of phosphine resistance in Sitophilus oryzae (L.) (Coleoptera: Curculionidae) populations collected from Mersin and Konya Province in Turkey were investigated by conducting the discrimination concentration tests and the concentration–mortality bioassays. Discriminating concentration tests showed that 89.9 and 83.3 % populations of tested total S. oryzae populations collected from Mersin and Konya province respectively were resistance to phosphine, which reveals high prevalence of phosphine resistance in the insect sampling locations of both provinces. Moreover, discrimination low concentration (0.04 mg/l) tests indicated that 62.5 and 33.3% of total S. oryzae populations collected from Mersin and Konya province respectively had 90% or above survival rate, which showed that the frequency of high phosphine resistance in S. oryzae populations collected from Mersin province was higher than that in S. oryzae populations collected from Konya province. The concentration–mortality bioassays indicated that there were significant differences in resistance levels of S. oryzae populations collected from different provinces. Based on the resistance factors (RF) calculated by LC50 values S. oryzae populations from Mersin and Konya province were 102- to 104-fold and 38- and 81-fold resistance to phosphine compared with susceptible S. oryzae population, respectively. The highest level of phosphine resistance was determined in S. oryzae populations from Mersin province, followed by those from Konya provinces, respectively. These results indicated that S. oryzae populations from Mersin province had higher phosphine resistance than those from Konya Province. In conclusion, this study showed that high levels of phosphine resistance in S. oryzae populations collected from different grain storages in Mersin and Konya province of Turkey were prevalent.In this study, the status and prevalence of phosphine resistance in Sitophilus oryzae (L.) (Coleoptera: Curculionidae) populations collected from Mersin and Konya Province in Turkey were investigated by conducting the discrimination concentration tests and the concentration–mortality bioassays. Discriminating concentration tests showed that 89.9 and 83.3 % populations of tested total S. oryzae populations collected from Mersin and Konya province respectively were resistance to phosphine, which reveals high prevalence of phosphine resistance in the insect sampling locations of both provinces. Moreover, discrimination low concentration (0.04 mg/l) tests indicated that 62.5 and 33.3% of total S. oryzae populations collected from Mersin and Konya province respectively had 90% or above survival rate, which showed that the frequency of high phosphine resistance in S. oryzae populations collected from Mersin province was higher than that in S. oryzae populations collected from Konya province. The concentration–mortality bioassays indicated that there were significant differences in resistance levels of S. oryzae populations collected from different provinces. Based on the resistance factors (RF) calculated by LC50 values S. oryzae populations from Mersin and Konya province were 102- to 104-fold and 38- and 81-fold resistance to phosphine compared with susceptible S. oryzae population, respectively. The highest level of phosphine resistance was determined in S. oryzae populations from Mersin province, followed by those from Konya provinces, respectively. These results indicated that S. oryzae populations from Mersin province had higher phosphine resistance than those from Konya Province. In conclusion, this study showed that high levels of phosphine resistance in S. oryzae populations collected from different grain storages in Mersin and Konya province of Turkey were prevalent
Mitochondrial genome organization varies among different groups of the booklouse, Liposcelis bostrychophila: Poster
Get PDFThe booklouse, Liposcelis bostrychophila is an important stored pest worldwide. The mt genome of an asexual strain (Beibei, China) of the booklouse, L. bostrychophila, comprises two chromosomes; each chromosome contains approximate half of the 37 genes typically found in animals. The mt genomes of two sexual strains of L. bostrychophila, however, comprise five and seven chromosomes respectively; each chromosome contains one to six genes. To understand mt genome evolution in L. bostrychophila, we sequenced the mt genomes of six strains of asexual L. bostrychophila collected from different locations in China, Croatia and USA. The mt genomes of all of the six asexual strains of L. bostrychophila collected in China, Croatia and USA have two chromosomes. Phylogenetic analysis of mt genome sequences divided nine strains of L. bostrychophila into four groups. Each group has a distinct mt genome organization and substantial sequence divergence (48.7-87.4%) from other groups. Furthermore, the seven asexual strains of L. bostrychophila including the published Beibei strain are more closely related to two other species of booklice, L. paeta and L. sculptilis, than to the sexual strains of L. bostrychophila. Our results revealed highly divergent mt genomes in the booklouse, L. bostrychophila, and indicated that L. bostrychophila is a cryptic species.The booklouse, Liposcelis bostrychophila is an important stored pest worldwide. The mt genome of an asexual strain (Beibei, China) of the booklouse, L. bostrychophila, comprises two chromosomes; each chromosome contains approximate half of the 37 genes typically found in animals. The mt genomes of two sexual strains of L. bostrychophila, however, comprise five and seven chromosomes respectively; each chromosome contains one to six genes. To understand mt genome evolution in L. bostrychophila, we sequenced the mt genomes of six strains of asexual L. bostrychophila collected from different locations in China, Croatia and USA. The mt genomes of all of the six asexual strains of L. bostrychophila collected in China, Croatia and USA have two chromosomes. Phylogenetic analysis of mt genome sequences divided nine strains of L. bostrychophila into four groups. Each group has a distinct mt genome organization and substantial sequence divergence (48.7-87.4%) from other groups. Furthermore, the seven asexual strains of L. bostrychophila including the published Beibei strain are more closely related to two other species of booklice, L. paeta and L. sculptilis, than to the sexual strains of L. bostrychophila. Our results revealed highly divergent mt genomes in the booklouse, L. bostrychophila, and indicated that L. bostrychophila is a cryptic species
Taxon identification of plant tissue-containing herbal mixtures using single molecule real time sequencing
Get PDFInfluence of abiotic factors on the efficacy of insect growth regulators against Trogoderma granarium (Everts)(Coleoptera: Dermestidae): Presentation
Get PDFPresent study was designed to investigate the effects of different combinations of three temperatures (20, 25 and 30?) and three relative humidity levels (55, 65 and 75%) on the efficacy of three synthetic IGRs i.e., pyriproxyfen, lufenuron and buprofezin at concentrations of 1, 5 and 10ppm on fecundity and adult emergence inhibition of T. granarium under controlled laboratory conditions. This study was conducted at Grain Research Training and Storage management Cell, Department of Entomology, University of Agriculture, Faisalabad, Pakistan. All the treatments were replicated three times using Completely Randomized Design. Larvae of T. granarium were exposed to IGRs at different levels of temperature and relative humidity. F1 adult emergence results showed that at temperature 20°C, the highest percent reduction in adult emergence (84.38, 70.65 and 79.94%) was recorded after exposure to lufenuron, buprofezin and pyriproxyfen treated diet, respectively. At 75% relative humidity, lufenuron, buprofezin and pyriproxyfen caused 77.53, 80.00 and 80.32% reduction in adult emergence, respectively. Adults were exposed to IGRs at different temperature and relative humidity to evaluate the oviposition inhibition. The results revealed that at temperature 20°C, maximum percent reduction in fecundity (87.95, 80.45 and 70.55%) was recorded after exposure to buprofezin, pyriproxyfen and lufenuron treated diet, respectively. At 75% relative humidity buprofezin, pyriproxyfen and lufenuron caused 86.73, 83.72 and 69.11% reduction in fecundity, respectively. It is concluded that temperature and relative humidity play an important role in the effectiveness of insect growth regulators.Present study was designed to investigate the effects of different combinations of three temperatures (20, 25 and 30?) and three relative humidity levels (55, 65 and 75%) on the efficacy of three synthetic IGRs i.e., pyriproxyfen, lufenuron and buprofezin at concentrations of 1, 5 and 10ppm on fecundity and adult emergence inhibition of T. granarium under controlled laboratory conditions. This study was conducted at Grain Research Training and Storage management Cell, Department of Entomology, University of Agriculture, Faisalabad, Pakistan. All the treatments were replicated three times using Completely Randomized Design. Larvae of T. granarium were exposed to IGRs at different levels of temperature and relative humidity. F1 adult emergence results showed that at temperature 20°C, the highest percent reduction in adult emergence (84.38, 70.65 and 79.94%) was recorded after exposure to lufenuron, buprofezin and pyriproxyfen treated diet, respectively. At 75% relative humidity, lufenuron, buprofezin and pyriproxyfen caused 77.53, 80.00 and 80.32% reduction in adult emergence, respectively. Adults were exposed to IGRs at different temperature and relative humidity to evaluate the oviposition inhibition. The results revealed that at temperature 20°C, maximum percent reduction in fecundity (87.95, 80.45 and 70.55%) was recorded after exposure to buprofezin, pyriproxyfen and lufenuron treated diet, respectively. At 75% relative humidity buprofezin, pyriproxyfen and lufenuron caused 86.73, 83.72 and 69.11% reduction in fecundity, respectively. It is concluded that temperature and relative humidity play an important role in the effectiveness of insect growth regulators
The significance of vapor pressure in quality preservation of stored commodities under gastight conditions: Presentation
No full textWhile investigating the preservation of the aroma of various spices we compared the effects of hermetic conditions, vacuum and carbon dioxide versus aerated storage. The quality of the tested spices stored under hermetic conditions was comparable to those stored in vacuum after 120 d of storage. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure. Throughout the investigation on specialty coffee, the volatility was evaluated as particularly important because coffee taste and aroma are influenced by compounds that are volatile. We hypothesize that hermetic storage reduces the rate of the volatiles to spread to the atmosphere. Dry food commodities can be stored for extended periods, provided there is no insect infestation and their water activity is low enough to prevent microbial growth. However, in aerated storages quantitative and qualitative losses still occur. If the moisture content is maintained sufficiently low, insects and quality loss remain the main concern for the quality preservation of durable agricultural commodities. Although in hermetic storage, the major emphasis is placed on the control of insect pests, for quality preservation just maintaining the vapor pressure in the sealed structure is sufficient. Quality preservation under hermetic conditions remains an aspect that deserves more attention. This characteristic of hermetic storage is the tendency to maintain within the hermetic structure the substances that have the ability to vaporize.While investigating the preservation of the aroma of various spices we compared the effects of hermetic conditions, vacuum and carbon dioxide versus aerated storage. The quality of the tested spices stored under hermetic conditions was comparable to those stored in vacuum after 120 d of storage. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure. Throughout the investigation on specialty coffee, the volatility was evaluated as particularly important because coffee taste and aroma are influenced by compounds that are volatile. We hypothesize that hermetic storage reduces the rate of the volatiles to spread to the atmosphere. Dry food commodities can be stored for extended periods, provided there is no insect infestation and their water activity is low enough to prevent microbial growth. However, in aerated storages quantitative and qualitative losses still occur. If the moisture content is maintained sufficiently low, insects and quality loss remain the main concern for the quality preservation of durable agricultural commodities. Although in hermetic storage, the major emphasis is placed on the control of insect pests, for quality preservation just maintaining the vapor pressure in the sealed structure is sufficient. Quality preservation under hermetic conditions remains an aspect that deserves more attention. This characteristic of hermetic storage is the tendency to maintain within the hermetic structure the substances that have the ability to vaporize
Residual behaviour of phosphine in different commodities: Presentation
Get PDFPhosphine is one of the most common active substances used in storage protection worldwide. As it is very efficient amongst a broad range of living organisms, it has become the favoured product after phasing out methyl bromide in 2010, as it can be used in many commodities. In 2005, the regulation 396/2005 was enacted and came into force in 2008. With this, the European commission started to evaluate residues arising from the use of a pesticide and to set maximum residue levels (MRLs) for safe and regulated food trade. To proof residue levels are below MRL and therefore far below concerning concentrations of phosphine in food or feed, residue studies are permanently conducted. In addition to support MRL settings, the intention of these trials is to determine withholding periods needed in storage protection, corresponding to PHI (pre harvest interval) for field and glasshouse treatments. Results of those studies show different levels and differences in decrease of residues after defined time periods. Thus, withholding periods for various commodities can differ. Residue trials with repeated exposure were conducted as well to determine possible additive effects.Phosphine is one of the most common active substances used in storage protection worldwide. As it is very efficient amongst a broad range of living organisms, it has become the favoured product after phasing out methyl bromide in 2010, as it can be used in many commodities. In 2005, the regulation 396/2005 was enacted and came into force in 2008. With this, the European commission started to evaluate residues arising from the use of a pesticide and to set maximum residue levels (MRLs) for safe and regulated food trade. To proof residue levels are below MRL and therefore far below concerning concentrations of phosphine in food or feed, residue studies are permanently conducted. In addition to support MRL settings, the intention of these trials is to determine withholding periods needed in storage protection, corresponding to PHI (pre harvest interval) for field and glasshouse treatments. Results of those studies show different levels and differences in decrease of residues after defined time periods. Thus, withholding periods for various commodities can differ. Residue trials with repeated exposure were conducted as well to determine possible additive effects