Impact of some plant powders on Sitophilus granarius (L.) and Rhizopertha dominica (Fab.) for protecting wheat grain

Author(s):  
Reda S. Hassan ◽  
Thanaa M. Sileem ◽  
Amira A. Mikhaiel ◽  
Karam Kh.El- Gizawy
2017 ◽  
Vol 37 (04) ◽  
pp. 243-258 ◽  
Author(s):  
Charles Adarkwah ◽  
Daniel Obeng-Ofori ◽  
Vanessa Hörmann ◽  
Christian Ulrichs ◽  
Matthias Schöller

Abstract Food losses caused by insects during postharvest storage are of paramount economic importance worldwide, especially in Africa. Laboratory bioassays were conducted in stored grains to determine the toxicity of powders of Eugenia aromatica and Moringa oleifera alone or combined with enhanced diatomaceous earth (Probe-A® DE, 89.0% SiO2 and 5% silica aerogel) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus. Adult mortality was observed up to 7 days, while progeny production was recorded at 6–10 weeks. LD50 and LT50 values for adult test insects exposed to plant powders and DE, showed that A. obtectus was the most susceptible towards the botanicals (LD50 0.179% and 0.088% wt/wt for E. aromatica and M. oleifera, respectively), followed by S. granarius. Tribolium castaneum was most tolerant (LD50 1.42% wt/wt and 1.40% wt/wt for E. aromatica and M. oleifera, respectively). The combined mixture of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT50 ranged from 55.7 h to 62.5 h for T. castaneum exposed to 1.0% M. oleifera and 1.0% DE, and 0.5% E. aromatica and 1.0% DE, respectively. Botanicals caused significant reduction of F1 adults compared to the control. Combined action of botanical insecticides with DE as a grain protectant in an integrated pest management approach is discussed.


Author(s):  
S. Ahmed ◽  
A. Zia ◽  
S. A. Mehmood ◽  
W. A. Panhwar ◽  
W. Khan ◽  
...  

Abstract Poor storage conditions provide favorable environment to stored grain pests for their growth. The bio-pesticides are the best alternatives to synthetic pesticides. Present study was conducted to compare toxicity of Rubus fruticosus and Valeriana jatamansi against granary weevil, Sitophilus granarius and subsequent changes in enzyme activity responsible for grain damage. In current research 5 g of R. fruticosus fruit and V. jatamansi rhizome powders were tested separately against S. granarius, in 50 g wheat whole grains for seven days in comparison with the control. The enzymatic activity of malate dehydrogenase and α-amylase was observed in the cellular extracts of S. granarius. The insects were crushed and homogenized in phosphate-buffer solution and centrifuged at 10000 rpm for 5 minutes. For the enzymatic measurement supernatant was tested; the spectrophotometer was adjusted at 340 nm. The reagents were mixed and incubated at 25 °C for five minutes. The cuvettes were placed in the experimental and reference sites of spectrophotometer and recorded the change in absorbance for 3-4 minutes. There was 5.60% and 14.92% reduction in the activity of malate dehydrogenase in R. fruticosus and V. jatamansi, treated insects, respectively. The alpha amylase enzyme activity was 6.82% reduced and 63.63% increase in R. fruticosus and V. jatamansi, treated insects, respectively. Present study addresses that both plant powders are effective against granary weevil by altering enzyme activities so both the plant powders can be used as bio-pesticides against the stored grains pests.


2010 ◽  
Vol 25 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Petar Kljajic ◽  
Ilija Peric

The effects of prior contact of granary weevil (Sitophilus granarius L.) parents from a laboratory population, a Belgrade Port population (selected with LD70 pirimiphos-methyl) and a Bijeljina population (selected with LD70 deltamethrin) with filter paper treated with sublethal doses (LD20 and LD50) of the insecticides dichlorvos, malathion, chlorpyrifos-methyl, pirimiphos-methyl and deltamethrin on offspring production of the surviving insects in F1 generation (after 10 weeks) and F2 generation (after 16 weeks) in untreated wheat grain was examined under laboratory conditions. Offspring reduction of laboratory weevils was highest at 96% in the F1 generation after parents' contact with LD50 dichlorvos, and lowest in F2 generation after contact with LD50 pirimiphos-methyl with 84% more insects than in the control. The highest offspring reduction of selected weevils from Belgrade Port, 83%, was recorded in F1 generation after treatment with LD50 dichlorvos and chlopyrifos-methyl, and the lowest in F1 and F2 generations after contact with LD50 pirimiphos-methyl, around 44%. The highest offspring reduction of the selected weevils from Bijeljina, 100%, was found in F1 and F2 generations after contact with LD50 dichlorvos, malathion and deltamethrin, and the lowest again in F1 and F2 generations after contact with LD20 chlorpyrifos-methyl, in which case insect numbers were some 130% higher than in the control. The results indicate that sublethal insecticide doses, apart from a significant decrease in their efficacy against treated granary weevil populations, may also provoke an increase in insect numbers in the following generations.


2021 ◽  
Vol 30 (9) ◽  
pp. 48-50
Author(s):  
G.A. Zakladnoy ◽  
◽  
A.V. Yaitskikh ◽  
D.S. Stepanenko ◽  
◽  
...  

Experimental studies have established a mathematical dependence of the uric acid content in wheat grain on the density of its Sitophilus granarius.


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 806
Author(s):  
Mariusz Nietupski ◽  
Emilia Ludwiczak ◽  
Robert Cabaj ◽  
Cezary Purwin ◽  
Bożena Kordan

Sitophilus granarius (L.) is considered to be one of the major pests causing damage to cereal grain stored in silos and granaries. Using traditional methods (synthetic insecticides, mechanical, or physical methods) to control this pest is either ineffective or dangerous to people and nature. It is, therefore, necessary to develop new cultivars of cereals that will be distinguished by a high natural tolerance of the foraging by S. granarius. The aim of this study is expressed in the set research hypothesis, stating that the number of offspring of the grain weevil on stored wheat kernels can depend on the content of fatty acids in the kernels. Thus, the qualitative and quantitative composition of fatty acids was determined in kernels of 10 winter wheat cultivars, and the abundance of the beetle’s offspring generation of S. granarius that developed on the wheat grain, as well as the mass of produced dust and loss in the mass of wheat grain were determined. By applying statistical analyses (GLM, ANOVA, Pearson’s linear correlation coefficient, and analysis of redundancy), the presence and character of the dependence between the determined content of fatty acids in wheat grain and the factors describing the development of S. granarius were established. The research results indicate that fatty acids from the groups C 18:1 and C 20:1 probably play an important role as substances stimulating the increase in the number of the tested pest progeny. In contrast, fatty acids C 15:0, C 16:1, and C 18:3, which were determined in large amounts in the grain of wheat cultivars Speedway, KWS Livius, and Julius, can reduce the number of offspring of pest insect.


2009 ◽  
Vol 27 (No. 3) ◽  
pp. 210-215 ◽  
Author(s):  
D. Kuzmanov ◽  
N. Dimitrov

According to the simulation models composed for the population growth and feeding damage of the insects: <i>Sitophilus oryzae</i> (L.), <i>Sitophilus granarius</i> (L.) and <i>Rhizopertha dominica</i> (F.) the populations densities have been determined at which the grain fumigation costs at using phosphorus hydrogen preparations equal the damage values caused by insects. The necessity of fumigation can be forecasted, according to the population growth time up to these limits. For this purpose, simulation models at temperatures of 21, 24, 27, and 30°C have been used. The products of time and temperature should be calculated at different temperatures and compared according to the simulation results and forecast temperature values during grain storage in particular granary. The action thresholds have been determined according to the models, at which fumigation should be carried out so that no economical losses or quality deterioration of grain be admitted. The results forecast have also been confirmed by freshly harvested wheat storage in a flat storehouse and a metal silo bin. It has been established that grain fumigation can be avoided if grain is stored in flat storehouses and cooled down by ventilation.


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