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1.
Five esters, butyl acetate, allyl acetate, ethyl acetoacetate, isopropyl acetate and propyl acetate, were screened as fumigants in the laboratory for 24 h at 27 (+/-2) degrees C against the adults of Rhyzopertha dominica (F), Sitophilus oryzae (L) and Tribolium castaneum (Herbst). Of the compounds tested, allyl acetate was the most toxic, with LD(99) values of 7.56, 12.81 and 11.42 mg litre(-1) against R dominica, S oryzae and T castaneum, respectively. Tests with allyl acetate against mixed-age cultures of Cryptolestes ferrugineus (Stephens), Oryzaephilus surinamensis (L), R dominica, S oryzae and T castaneum revealed that doses of 50-150 mg litre(-1) with 24-120-h exposures were necessary to achieve 100% mortality of all life stages. Cryptolestes ferrugineus was the most tolerant insect tested, whilst R dominica was highly susceptible. The insect toxicity data indicates that allyl acetate has potential as a fumigant of stored food grains.  相似文献   

2.
Spinosad, a reduced-risk commercial insecticide derived from a bacterial fermentation product, possesses both contact and oral toxicities against insects. Contact toxicity of spinosad to adults of Rhyzopertha dominica (F), Sitophilus oryzae (L), and Tribolium castaneum (Herbst) was evaluated by exposure for 24 or 48 h to treated glass Petri dishes. Adults were exposed to different deposits (0.001-0.79 mg cm(-2)) of spinosad in 24-h tests and to deposits of 0, 0.0016 and 0.016mg cm(-2) in 48-h tests. Rhyzopertha dominica was most susceptible to spinosad in 24- and 48-h tests, followed by S. oryzae, and T. castaneum. The 24-h LD50 values were 0.0004, 0.077 and 0.189mg cm(-2) for R. dominica, S. oryzae, and T. castaneum, respectively. All R. dominica adults were dead following 48 h exposure to both spinosad deposits, whereas mortality of S. oryzae and T. castaneum ranged from 10 to 85% and 12 to 48%, respectively. Rhyzopertha dominica, T. castaneum, and O. surinamensis adults were exposed for 14 days to whole wheat, cracked wheat and wheat flour treated with 0, 0.1 and 1.0 mg kg(-1) of spinosad. Rhyzopertha dominica adults were highly susceptible to spinosad, followed by O. surinamensis and T. castaneum. Immatures (eggs and larvae) of T. castaneum and O. surinamensis exposed for 14 days were more susceptible on spinosad-treated whole wheat than on treated cracked wheat and wheat flour. This is the first report documenting contact activity of spinosad, and the effect of grain condition on spinosad toxicity, to stored-product insects.  相似文献   

3.
Hard red winter wheat was treated with pirimiphos-methyl at 4, 6 and 8 mg kg(-1), synergized pyrethrins at 0.38, 0.75, 1.13 and 1.5 mg kg(-1), and combinations of the two insecticides, to conduct laboratory bioassays against four beetle pests of stored grain, red flour beetle Tribolium castaneum (Herbst), rusty grain beetle Cryptolestes ferrugineus (Stephens), lesser grain borer Rhyzopertha dominica (F), and rice weevil Sitophilus oryzae (L), and one moth pest, Indianmeal moth Plodia interpunctella (Hubner). Beetle adults and P interpunctella larvae survived well on control wheat, producing a large number of progeny (65-1037 insects per container). Kernel damage in control wheat among the insect species ranged from 9 to 99%. On pirimiphos-methyl-treated wheat, mortality of R dominica adults was > or =72%, but that of the other beetle species and P interpunctella larvae was 100%. Progeny were not produced on pirimiphos-methyl-treated wheat, and the kernel damage was negligible (< or =1%). Synergized pyrethrins were ineffective against the five insect pests. Pirimiphos-methyl combined with synergized pyrethrins was not superior to pirimiphos-methyl alone against the five insect pests. Pirimiphos-methyl is not registered in the USA for use on wheat, but our results suggest that it could be a viable grain protectant at rates of 4-8 mg kg(-1).  相似文献   

4.
Ethyl formate is being evaluated as a fumigant for stored grain as it is a potential alternative to the ozone-depleting fumigant methyl bromide and to phosphine, which is under pressure owing to the development of strong resistance in stored grain insects. However, use of ethyl formate faces significant challenges, such as poor penetration through grain, significant losses to grain sorption, high concentrations of fumigant required to control insects, and flammability risks, which have limited its further development. In this study it was found that the combination of carbon dioxide (5-20%) with ethyl formate significantly enhanced efficacy of the fumigant against external living stages of the rice weevil, Sitophilus oryzae (L.), the lesser grain borer, Rhyzopertha dominica F., and the flour beetle, Tribolium castaneum (Herbst). Dynamic application of ethyl formate and carbon dioxide mixture (100 mg litre-1 ethyl formate, 20% CO2) pumped through a model silo containing wheat (50 kg) for one gas exchange was also investigated. A flow rate of 6 litres min-1 gave a relatively even distribution of fumigant throughout the grain column and similar mortality levels among cultures of S. oryzae and T. castaneum placed at three positions, the top, middle and bottom of the column. Mortality of 99.8% of mixed stage cultures of T. castaneum and 95.1% of S. oryzae was achieved in 3 h exposures to 111 and 185 mg ethyl formate h litre-1 respectively applied by the dynamic method. It is concluded that the combination of carbon dioxide with ethyl formate and dynamic application enhances distribution and efficacy of the fumigant against stored grain insects.  相似文献   

5.
The fecundity of four important coleopteran stored-grain pests, Rhyzopertha dominica (Fab.), Sitophilus oryzae (L.), Oryzaephilus surinamensis (L.) and Tribolium castaneum (Herbst.) was assessed after exposure to wheat treated with five benzoylphenyl ureas (BPUs), members of the chitin-synthesis inhibitor group of insect growth regulators (IGRs). Chlorfluazuron was found to control all four species more effectively than triflumuron, teflubenzuron, flufenoxuron or diflubenzuron. Two weeks of exposure of parents to 0.5 mg kg ?1 of all the BPUs, except diflubenzuron, inhibited almost all F1 production and all the F2 production of each species. The fecundities of T. castaneum and O. surinamensis recovered almost to their untreated levels after two weeks of exposure to 1 mg kg ?1 of BPUs followed by two weeks on untreated wheat, but the effect of the exposure persisted for at least two weeks on untreated wheat in adult S. oryzae and to a lesser extent in R. dominica. The mean F1 response of the four species after two weeks of exposure to four doses showed clearly that the four newer BPUs were all similar in their overall effectiveness and significantly more effective than diflubenzuron, although diflubenzuron was equally effective against S. oryzae. At 0.1 mg kg ?1 triflumuron was less effective against O. surinamensis, while teflubenzuron and flufenoxuron were not very effective against the rice weevil, S. oryzae. Chlorfluazuron provided the most effective control of all four stored-product pest species, including the weevil, S. oryzae. The BPUs show particular potential for use in the stored-product industry because low dosages will effectively control the rice weevil in addition to the other major pest species.  相似文献   

6.
A field experiment was carried out on bulk sorghum stored for 26 weeks in concrete silos in South Queensland. No natural infestation occurred. Laboratory bioassays of treated grain, in which malathion-resistant strains of insects were added to grain samples, indicated that all the treatments were generally effective. Deltamethrin (2mg kg−1)+piperonyl butoxide (8mg kg−1), fenitrothion (12mg kg−1)+fenvalerate (1 mg kg−1)+piperonyl butoxide (8mg kg−1), and fenitrothion (12mg kg−1)+phenothrin (2mg kg−1)+piperonyl butoxide (8mg kg−1) controlled typical malathion-resistant strains of Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst) and Ephestia cautella (Walker). Pirimiphos-methyl (6mg kg−1)+permethrin (1mg kg−1)+piperonyl butoxide (8mg kg−1) allowed some survival of adults and progeny production by S. oryzae after 12 weeks, and by one strain of R. dominica throughout. Chemical assays established that the residues and rates of breakdown of these grain protectants on sorghum conformed to the general pattern on other cereal grains. Residues at the conclusion of the experiment were below the individual Maximum Residue Limits recommended by the Codex Alimentarius Commission.  相似文献   

7.
为探明臭氧对主要储粮害虫的熏蒸效果及其与磷化氢抗性的关系,本研究采用臭氧发生装置测定浓度为0.84 g/m^3臭氧对5种主要储粮害虫(赤拟谷盗、杂拟谷盗、玉米象、锈赤扁谷盗、谷蠹)的熏蒸效果,及对具有不同磷化氢抗性的赤拟谷盗(抗性系数为1.7~862.7)和杂拟谷盗(抗性系数为2.3~144.7)的毒力效果,并统计分析了试虫经臭氧熏蒸1 h后在不同时间内的行为状态差异。研究结果表明:在0.84 g/m^3臭氧浓度下,5种害虫对臭氧均具有较强敏感性,其LT50在0.58~1.53 h,其中谷蠹对臭氧的耐受性相对最强;赤拟谷盗和杂拟谷盗的不同磷化氢抗性品系对臭氧的敏感性差异较小,表明磷化氢与臭氧无交互抗性。经臭氧熏蒸1 h后,试虫有正常爬行、非正常爬行和死亡3种行为状态,其中较大比例的试虫(24%~66%)处于非正常爬行状态,且持续时间较长,约10 d后此部分试虫恢复正常或死亡。结果表明,臭氧对储粮害虫具有高效性和广谱性,且与磷化氢无交互抗性,可作为储粮害虫防治及磷化氢抗性治理药剂。  相似文献   

8.
BACKGROUND: Gaseous ozone (O3) has potential for control of insects in stored grain. Previous studies have focused on freely exposed insects. Immatures of internal pests (e.g. Sitophilus spp. and most stages of Rhyzopertha dominica F.) are protected within kernels and probably require higher doses and/or longer treatment times for full control. A laboratory study determined the doses of ozone necessary for full control of freely exposed and internal stages of eleven stored‐product pest species. Test insects were three species of Sitophilus, R. dominica, Tribolium confusum Jacquelin du Val, T. castaneum Herbst, Plodia interpunctella Hübner, Sitotroga cerealella Olivier, Oryzaephilus surinamensis L., Ephestia kuehniella Zeller and Stegobium paniceum L. Insects were exposed to continuous flows of ozone in doses of 10–135 ppm and exposure times of 5–8 days. Dose‐mortality bioassays were conducted on three species of Sitophilus and P. interpunctella. RESULTS: Freely exposed stages (with a few exceptions) were controlled with 35 ppm of ozone for 6 days. Full mortality of internal stages within kernels required exposure to 135 ppm for 8 days. CONCLUSION: This study confirms that higher doses and/or longer treatment times are necessary for control of internal stages of stored‐product pests. Copyright © 2012 Society of Chemical Industry  相似文献   

9.
Five species of stored-product insects, [Tribolium castaneum (Herbst), T. confusum (DuVal), Rhyzopertha dominica (F.), Sitophilus oryzae (L.) and S. granarius (L.)], exposed to phosphine in nitrogen and various oxygen-deficient atmospheres, showed reduced susceptibility to three concentrations of phosphine (0.02, 0.04 and 0.2 mg litre?1). The last two species also showed reduced susceptibility to phosphine at 2.0 mg litre?1. Generally mortality increased progressively as the level of oxygen was raised. There was a close relationship between the ability of insects to withstand anoxia and survival from phosphine treatment.  相似文献   

10.
Duplicate field trials were carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays on samples of treated grain at intervals over 8 or 9 months storage using malathion-resistant strains of insects established that treatments were generally effective. Cyfluthrin (2 mg kg?1) plus piperonyl butoxide (10 mg kg?1) and cypermethrin (4 mg kg?1) plus piperonyl butoxide (10 mg kg?1) completely controlled two strains of Sitophilus oryzae L. Control of a third strain by the cypermethrin combination was incomplete after 11/2 months and neither controlled a multi-resistant laboratory strain. Both combinations were effective against Rhyzopertha dominica F., Tribolium castaneum Herbst and Ephestia cautella Walker. No natural infestation developed in the treated grain in any silo. Mean residues of cyfluthrin and cypermethrin after 9 months storage were 58% and 52% of the calculated application rates, respectively. Compared with overall concentrations in the wheat, residue levels were higher in bran and pollard and lower in white flour. During baking, residues decreased by up to 29%. Operators experienced respiratory irritation associated with exposure to both combinations and alternative formulations would be required for use of these materials in grain storage.  相似文献   

11.
Insecticidal fumigation toxicity of natural and synthetic cyanohydrins was evaluated with four stored-product pests: the lesser grain borer, Rhyzopertha dominica (F), the red flour beetle, Tribolium castaneum Herbst, the saw-toothed grain beetle Oryzaephilus surinamensis L, the maize weevil, Sitophilus zeamais (Motsch) and the house fly, Musca domestica L. The fumigation LC50 values were calculated by probit analysis. For house flies, all but one of the cyanohydrins tested were more potent than 1,3-dichloropropene (Telone). Three were as efficacious as chloropicrin. For the lesser grain borer, all cyanohydrins tested were more insecticidal than dichloropropene, and all but one were more potent than chloropicrin. Four were as insecticidal as dichlorvos. The acetate of 1-cyano-1-hydroxy-2-propene (CHP-ace) was also tested in soil for antifungal and antibacterial activity, and inhibition of weed seed germination. CHP-ace reduced the total soil bacterial and fungal counts significantly, and was effective in inhibiting the germination of weed seeds in soil, indicating a broad spectrum of activity as a soil fumigant.  相似文献   

12.
Duplicate experiments were carried out on bulk sorghum stored in South Queensland and in Central Queensland. Bioassays of treated grain, conducted during 6 months' storage, established that fenitrothion (12 mg kg?1)+ bioresmethrin (1 mg kg?1), and pirimiphos-methyl (4 mg kg?1)+ carbaryl (8 mg kg?1), controlled typical malathionresistant strains of Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst), and Ephestia cautella (Walker). Chlorpyrifos-methyl (10 mg kg?1)+ pyrethrins (1.5 mg kg?1)+ piperonyl butoxide (12 mg kg?1), and fenitrothion (12 mg kg?1)+ (1R)-phenothrin (1 mg kg?1), also controlled the strains of S. oryzae, T. castaneum and E. cautella, but were only partly effective against R. dominica. Methacrifos (15 mg kg?1) controlled all the tested species except E. cautella. Chemical assays established that the residues and rates of breakdown of these grain protectants on sorghum conformed to the general pattern for other cereal grains; residues from the above treatments were below the individual Maximum Residue Limits recommended by the Codex Alimentarius Commission.  相似文献   

13.
In laboratory experiments, whole wheat was treated with pirimiphos-methyl or carbaryl or combinations of these two insecticides; the treated grain was then adjusted to a 12% moisture content and stored at 25°C for bioassay at various intervals over a period of 39 weeks. Pirimiphos-methyl at 5.1 mg kg?1 effectively controlled Sitophilus granarius (L.) and Tribolium confusum Jacquelin du Val but was ineffective against Rhyzopertha dominica (F.) CRD 118, a strain showing malathion resistance. Conversely, carbaryl at 6.5 mg kg?1 (but not at 3.1 mg kg?1) was effective against R. dominica, but ineffective against the other two species. A combination of pirimiphosmethyl + carbaryl, at 1.8 + 5.1 mg kg?1, controlled S. granarius and R dominica but not T. confusum, whilst a 4.2 + 3.4 mg kg?1 combination was relatively more effective against T. confusum but less so against R. dominica. In a separate experiment, whole wheat was treated with carbaryl at 2.5, 5.0 and 7.5 mg kg?1 (nominal rates). Samples were stored and, at various times after the treatments, were bioassayed with R. dominica CRD 2, at 20, 25, 30 and 35°C. The results were comparable with those for the CRD 118 strain, but efficacy was reduced at higher temperatures. The combination of pirimiphos-methyl at 4–5 mg kg?1 and carbaryl at 5–6 mg kg?1 is suggested as a potentially useful grain protectant where R. dominica is a problem and long term storage is required. These results are discussed in relation to the protection of stored grain in Australia.  相似文献   

14.
The toxicity of allyl alcohol as a fumigant was assessed for adults ofTribolium castaneum (Herbst.),Rhyzopertha dominica (F.) andSitophilus oryzae (L.). Fumigations were carried out in 3.4–1 glass containers at concentrations of 1–15 mg/l for 3 h. The most sensitive species wasS. oryzae and the most tolerant wasT. castaneum. A dose of 15 mg/l for 3 h was lethal to all three species tested. The feasibility of proposing allyl alcohol as a candidate fumigant is discussed. Publication of the Agricultural Research Organization.  相似文献   

15.
The responses of five species of adult stored-product insects [Tribolium castaneum (Herbst), T. confusum (DuVal), Rhyzopertha dominica (F.), Sitophilus oryzae (L.) and S. granarius (L.)] to various doses of phosphine in atmospheres of air or nitrogen were determined. A few S. oryzae and S. granarius survived phosphine concentrations up to 80 mg litre?1 for 24 h in normal (air) or nitrogen atmospheres. By contrast, T. castaneum, T. confusum and R. dominica could not tolerate more than 0.2 mg phosphine litre?1 in air for 12 h. However, they could tolerate up to 10 mg phosphine litre?1 in nitrogen for that period. Increasing the phosphine concentration resulted in increased mortalities of the last three species. The possible mechanism underlying this response is discussed. The reproductive potential of insects surviving phosphine exposure in a nitrogen atmosphere was unaffected.  相似文献   

16.
Pan W  Luo P  Fu R  Gao P  Long Z  Xu F  Xiao H  Liu S 《Pest management science》2006,62(3):283-287
An acaricidal substance extracted from the external seed coat of Ginkgo biloba L. was identified by UV (ultraviolet), IR (infrared), EI-MS (electron impact ion source mass spectrometry), (1)H NMR (nuclear magnetic resonance) and (13)C NMR as 6-[(Z)-10-heptadecenyl]-2-hydroxybenzoic acid (compound 1). Laboratory bioassay on citrus red mite, Panonychus citri (Mcg), showed that compound 1 possessed the following properties. (i) Powerful contact toxicity with an LC(50) of 5.2 mg litre(-1) after 24 h that was similar to that of pyridaben (LC(50) = 3.4 mg litre(-1)) and significantly superior to that of omethoate (LC(50) = 122 mg litre(-1)). Furthermore, its LC(90) was 13.4 mg litre(-1) after 24 h, which is significantly superior to both pyridaben (LC(90) = 69.6 mg litre(-1)) and omethoate (LC(90) = 453 mg litre(-1)). (ii) Quick-acting acaricidal activity. At identical concentrations, compound 1 was much faster-acting than pyridaben or omethoate. (iii) Compound 1 had strong corrosive action on the cuticle of P. citri but no phytotoxicity to plants.  相似文献   

17.
Resistance to fumigants has been frequently reported in insect pests of stored products and is one of the obstacles in controlling these pests. The authors studied phosphine resistance and its physiological basis in adult insects of 12 populations of Tribolium castaneum (Herbst) (Tenebrionidae), ten populations of Rhyzopertha dominica (F.) (Bostrichidae) and eight populations of Oryzaephilus surinamensis L. (Silvanidae) from Brazil, and the possible existence of fitness costs associated with phosphine resistance in the absence of this fumigant. The bioassays for the detection of phosphine resistance followed the FAO standard method. The production of carbon dioxide and the instantaneous rate of population increase (r(i)) of each population of each species were correlated with their resistance ratios at the LC(50). The resistance ratio at LC(50) in T. castaneum ranged from 1.0- to 186.2-fold, in R. dominica from 2.0- to 71.0-fold and in O. surinamensis from 1.9- to 32.2-fold. Ten populations of T. castaneum, nine populations of R. dominica and seven populations of O. surinamensis were resistant to phosphine. In all three species there was significant association (P < 0.05) between respiration rate and phosphine resistance. The populations with lower carbon dioxide production showed a higher resistance ratio, suggesting that the lower respiration rate is the physiological basis of phosphine resistance by reducing the fumigant uptake in the resistant insects. Conversely, populations with higher r(i) showed lower resistance ratios, which could indicate a lower rate of reproduction of the resistant populations compared with susceptible populations. Thus, management strategies based on the interruption of phosphine fumigation may result in reestablishment of susceptibility, and shows good potential for more effective management of phosphine-resistant populations.  相似文献   

18.
The response of Rhyzopertha dominica and Sitophilus oryzae (both phosphine-resistant) in mixed-age cultures to phosphine at fixed concentration-time products (CT) of 10,500 to 168,000 microliters litre 1 h (ppm h) with either constant, rising or falling concentrations for 7 days was studied at 27 (+/- 2) degrees C. At lower CT products, rising concentrations of phosphine led to significantly fewer survivors of R dominica and S oryzae. Conversely, exposure to falling concentrations of phosphine resulted in significantly more survivors. The influence of changing concentrations of phosphine was more pronounced in S oryzae than in R dominica. In the latter, at the lower CT products of 21,000 and 42,000 microliters-1 h, the adult stage proved to be most tolerant, contrary to the accepted belief that the egg or pupal stage are always more tolerant to phosphine. The results indicate that application of phosphine in rising concentrations is more effective than in constant or falling concentrations.  相似文献   

19.
The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae.  相似文献   

20.
Degree of dominance of phosphine resistance was investigated in adults of Rhyzopertha dominica F and Sitophilus oryzae L. Efficacy of the grain fumigant phosphine depends on both concentration and exposure period, which raises the possibility that dominance levels vary with exposure period. New and published data were used to test this possibility in adults of R dominica and S oryzae fumigated for periods of up to 144 h. The concentrations required for control of homozygous resistant and susceptible strains and their F1 hybrids decreased with increasing exposure period. For both species the response lines for the homozygous resistant and susceptible strains and their F1 hybrids were parallel. Therefore, neither dominance level nor resistance factor was affected by exposure period. Resistance was incompletely recessive and the level of dominance, calculated at 50% mortality level, was -0.59 for R dominica and -0.65 for S oryzae. The resistant R dominica strain was 30.9 times more resistant than the susceptible strain, compared with 8.9 times for the resistant S oryzae strain. The results suggest that developing discriminating doses for detecting heterozygote adults of either species will be difficult.  相似文献   

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