New trends for controlling Sitophilus oryzae concerning adult mortality, offspring production, mode of action, and grain quality

Author(s):  
Aly Derbalah ◽  
Attiah Keratum ◽  
Mohamed Darweesh ◽  
Mostafa Elebiary ◽  
Fatma Hegazy
2005 ◽  
Vol 78 (3) ◽  
pp. 105-116 ◽  
Author(s):  
R. Fourar ◽  
F. Fleurat-Lessard

The wheat bug, Aelia germari, feeds on developing wheat kernels, causing a loss in baking quality of the harvested wheat (Triticum aestivum). The possible nutritional changes in the bug-damaged kernels after the harvest were tested in a bioassay using the rice weevil Sitophilus oryzae, which feeds on the kernel endosperm. The weevils were reared on baking wheat cultivar 'Manon demias', grown in Algeria, with different levels (0, 4, 8 and 13%) of wheat bug (A. germari) damaged kernels. Rice weevil reared on 4, 8 or 13% damaged wheat had a shorter development time than on wheat with no damage. However, pair-wise correlations showed that Dobie's index for susceptibility of grain for stored-products insect attack, number of progeny per female and kernel weight loss were not correlated with the percentage of damaged kernels. Using multivariate analysis, the general characteristics of high quality grain were associated with long development times for S. oryzae, low number of progeny, high baking strength, high falling number, high nitrogen, low ash content, and low assimilable nitrogen.


2011 ◽  
Vol 51 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Aly Derbalah ◽  
Sahar Ahmed

Oil and Powder of Spearmint as an Alternative toSitophilus OryzaeChemical Control of Wheat GrainsStored product pests such asSitophilus Oryzaeare a major concern. Alternative and safe control methods for such pests are needed. Therefore, powder and essential oil of Mentha viridis plant were tested under laboratory conditions for their ability to protect wheat grains against the insectS. oryzae. The insect was reared and tested on whole wheat grains. The emergence and adult mortality of the insectS. oryzaewere tested. The efficacy of these plant products was evaluated and compared with malathion. The standard compound for controllingS. oryzaehas been malathion. The effect of botanical products and malathion on the germination of wheat grains was also evaluated. The chemical components of spearmint oil were also identified using GC-MS analysis. The results showed that, the oil and powder ofM. viridiswere effective againstS. oryzaewith the respect to adults mortality. Also, the oil and powdered products ofM. viridissignificantly reduced the emergence ofS. oryzaecompared to the control treatment. Spearmint oil and powder do not significantly affect wheat grains germination relative to the control treatment. The efficacy of spearmint against the tested insect was due to the presence of a mixture of bioactive compounds. The results suggested that, spearmint oil and powder are promising as alternatives to chemical control used againstS. oryzaein wheat grains. Also, these spearmint products submit a solution of resistance development by insect due to the presence of a lot of bioactive components rather than the single insecticide.


2018 ◽  
Vol 33 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Marijana Prazic-Golic ◽  
Petar Kljajic ◽  
Goran Andric ◽  
Nenad Tamas ◽  
Stefan Prazic

Residual efficacy of the insecticide deltamethrin, an EC formulation containing 25 g/L AI + 225 g/L PBO (piperonyl butoxide synergist), against lab populations of Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Sitotroga cerealella was investigated in the laboratory by applying product water solutions (0.25 mg AI/kg) to wheat grain (at 25?1?C and 60?5% r.h.). Adult mortality on 0, 7, 14 and 30 days old deposits was estimated after 2, 7 and 14 days of exposure to treated wheat grain and additional 7 days of recovery. Progeny reduction (PR, %) was also assessed. After 2 days of exposure to deposits of all ages, deltamethrin caused only 0-10% mortality of coleopterans (up to 37% after the recovery period) and 23-30% of S. cerealella, while mortality before and after recovery from 14 days of exposure was 95-50% for S. oryzae, 97-100% for R. dominica, 99-100% for T. castaneum and 100% for S. cerealella. Progeny production of S. oryzae was highest after parents contacted with 14 days old deposit of deltamethrin (PR, 76%), and lowest after contact with fresh deposit (PR, 95%), while R. dominica and T. castaneum had no progeny on any deltamethrin deposit age in wheat (PR, 100%), and S. cerealella had only a very low progeny (PR, 99%). The results showed that the synergised deltamethrin, applied at 0.25 mg/kg in wheat grain, is a highly effective insecticide for storedproduct insect control, while a higher dose is required for successful residual control of S. oryzae.


2006 ◽  
Vol 138 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Xingwei Hou ◽  
Wes Taylor ◽  
Paul Fields

AbstractProtein-rich pea flour is an antifeedant and a repellent and is toxic to the rice weevil, Sitophilus oryzae (L.), but its mode of action is not known. Results showed that protein-rich pea flour had no fumigant effect on adult survival or offspring production of S. oryzae. In a contact experiment, immobilized weevils were fed every other day and had their abdomens brushed with protein-rich pea flour or wheat flour on the alternate days. Insects treated with protein-rich pea flour had an average longevity of 9.6 days, which was significantly shorter than that for insects treated with wheat flour (11.3 days) or brushed controls (17.6 days). These results suggest that toxins from the protein-rich pea flour may be able to penetrate the insect cuticle. Midguts from weevils fed protein-rich pea flour, a pea flour extract, or a mixture of pea peptides contained numerous bubbles. Midgut tissues in these treated adults were injured, as shown by dual staining with the fluorescent dyes calcein AM and propidium iodide. The volume of the bubbles increased rapidly when insects were fed protein-rich pea flour or pea flour extract. There were no bubbles found in the midguts of S. oryzae that fed on wheat kernels or wheat flour.


2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Sekar Kanmani ◽  
Lokesh Kumar ◽  
Rajasingh Raveen ◽  
Samuel Tennyson ◽  
Subramanian Arivoli ◽  
...  

Abstract Background Rice is the agricultural commodity with the third highest worldwide production and losses in rice storage due to insect pests may drastically affect the food availability for a large number of people. One of its serious pests in tropics is the “rice weevil”, Sitophilus oryzae. Although few effective fumigants are available, there is a global concern about environmental pollution, toxicity to non-target organisms, and pesticide residues. Botanicals are a promising source of pest control compounds as the pool of plants possessing insecticidal substances are enormous and have generated extraordinary interest in recent years as potential sources of natural insect control agents. The present study was conducted to determine the toxicity of tobacco (Nicotiana tabacum) leaf extracts as an alternative to synthetic insecticides in the management of rice weevils. The crude solvent leaf extracts of N. tabacum were analyzed for its phytochemical compounds via GC-MS and tested for its toxicity to the adults of S. oryzae at concentrations of 0.625, 1.25, 2.50, 5.00, 10.00, and 20.00 mg/L by Petri dish bioassay method. Adult mortality was calculated 24, 48, and 72 h after exposure. Results The constituent compounds in the chloroform and acetone revealed 13 compounds represented by benzene carboxylic acid ester, alkaloids, and steroids. The major compounds found in GC-MS analysis are nicotine, nicotinonitrile, nornicotine, nicotinic acid, neonicotine, cotinine, indole, farnesol, sclareol, 9,12-octadecadienoic acid, squalene, palmitic acid, and 15-tetracosenoic acid methyl ester. Overall assessment indicates that the chloroform and acetone extracts of N. tabacum leaves exhibited the highest adulticidal activity against S. oryzae. Their LD50 values were 1.62, 0.64, and 0.48; 1.54, 0.83, and 0.48 mg/L after 24, 48, and 72 h of exposure respectively. In addition, the petroleum ether extract also indicated high adult mortality with LD50 value of 0.53 mg/L only at 72 h. Conclusions The present research has documented its first report for the management of rice weevil using tobacco leaf extracts, and therefore on the basis of the results of the present study, it is highly encouraging to note that the use of tobacco leaf extracts with its excellent insecticidal activity owing to the action of nicotine would be economically feasible to alleviate the rice weevil problem.


2019 ◽  
Vol 112 (4) ◽  
pp. 1964-1974 ◽  
Author(s):  
Darsana Divagar ◽  
Fuji Jian ◽  
Stefan Cenkowski

Abstract The effect of 105°C steam or hot air on adult mortality of three species of stored-product insect pests outside wheat kernels of 12.5, 14.5 and 16.5% moisture content was investigated. The species were Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), and Sitophilus oryzae (L.) (Coleoptera: Curculionidae). In the case of S. oryzae, young adults and immature stages inside wheat kernels were also tested. The mortality of insects inside kernels was higher at lower moisture contents of wheat treated with hot air, whereas moisture content did not significantly affect mortality of insects treated with steam. In the hot air treatment, all adults of the three species outside kernels had 100% mortality when the treatment time was 75 s for wheat with 16.5% moisture content, and 60 s for 12.5 and 14.5% wheat. In the steam treatment, the time to reach 100% mortality of adults outside kernels was 1 s at any moisture content and without significantly affecting germination. The young adults and immature stages of S. oryzae inside kernels required 90 s to reach 100% mortality in hot air, whereas 3 s was needed in steam. The treatment to reach 100% mortality of insects inside kernels caused a 20% drop in germination in steam and 81% drop in hot air.


2007 ◽  
Vol 70 (7) ◽  
pp. 1627-1632 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
CONSTANTIN J. SAITANIS ◽  
DEMETRIUS C. KONTODIMAS ◽  
ALEXANDER N. ROUSSOS ◽  
...  

The insecticidal effect of two azadirachtin-based insecticides, NeemAzal-T/S and Oikos 32 EC, was examined against adults of the grain beetles Sitophilus oryzae and Tribolium confusum on wheat and maize under different temperature and humidity regimes. The insecticides were applied at three dosages, equivalent to 50, 100, and 200 mg of active ingredient per kg of grain. Adults of the above species were exposed to the treated grains at 20, 25, and 30°C and two relative humidity levels (55 and 75%), and mortality was assessed after 14 days of exposure. All adults were then removed, and the treated substrate remained under the same conditions for 45 more days. After this period, the grains were checked for progeny production. In both species and both commodities, mortality increased with insecticide dosage. For many dosage-formulation combinations, mortality increased with temperature at 55% relative humidity but the reverse was observed at 75% relative humidity. Comparing the two formulations, NeemAzal-T/S was more effective than Oikos 32 EC at all the combinations tested. NeemAzal-T/S was more effective at high relative humidity, but the efficacy of Oikos 32 EC was not much affected by the relative humidity. Survival was high, even at the higher dosages, in some of the temperature-humidity combinations. Progeny production of S. oryzae in the treated grains was considerably higher than that of T. confusum. The results of the present study indicate that further dosage increases and longer exposure times are needed to obtain a complete (100%) adult mortality in all combinations tested. However, the feasibility of using higher azadirachtin dosages (>200 mg/kg grain) is questionable for cost reasons. Consequently, the use of these substances is not comparable to the use of traditional grain protectants, which are usually used at dosages of <5 mg/kg grain. Although azadirachtin-based insecticides can be used with success for protection of stored grain, our study demonstrated that under certain circumstances such an application may not be effective. Abiotic factors (formulation, temperature, and relative humidity) had a more serious impact on the efficacy of these insecticides than did biotic factors (target species and commodity).


2019 ◽  
Vol 112 (4) ◽  
pp. 1989-1996 ◽  
Author(s):  
Anastasia W Njoroge ◽  
Richard W Mankin ◽  
Bradley Smith ◽  
Dieudonne Baributsa

Abstract Modified atmospheres such as hermetic storage are widely used for the control of stored grain insect pests. To improve their effectiveness, there is need to better understand insect responses to low-oxygen environments. Adult Callosobruchus maculatus F. (Coleoptera: Chrysomelidae: Bruchinae) on cowpea and Sitophilus oryzae L. (Coleoptera: Curculionidae) on wheat were exposed to hypoxia treatments consisting of 1, 3, and 5% oxygen levels for 14 d. Acoustic activity was monitored during the experiment, and insect mortality and grain quality were examined immediately after the hypoxia treatments. Adult emergence was assessed 45 d post-treatment. All three hypoxia treatments eliminated acoustic activity of both species within 4 d. There was neither insect survival for both species nor significant grain damage immediately after 14-d exposure to hypoxia treatments. No adult insects emerged 45 d post-exposure on grains maintained at 1% oxygen level for 14 d. However, at 3 and 5% oxygen levels, there were eggs on cowpea, holes in wheat, and emerging adults for both insect species 45 d post-exposure. Although insect activity ceased within 4 d when hypoxia was maintained below 5%, there is need to explore exposure beyond 14 d for 3 and 5% oxygen levels, to ensure to avoid potential adult emergence from eggs and other insect life stages post-treatments. Maintaining 3–5% hypoxia conditions for a longer duration would ensure insufficient oxygen is available for progeny development.


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