Insecticidal effects of two medicinal plants Polygonum hydropiper L. and Abrus precatorius L. leaves against the rice weevil Sitophilus oryzae L. (Coleoptera: Curculionidae) (original) (raw)
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2015
This study was carried out to find the best combinations amongst essential oils of three medicinal plants, Vepris heterophylla (Rutaceae), Hyptis spicigera (Lamiaceae) and Ocimum canum (Lamiaceae) against Sitophilus oryzae (Coleoptera: Curculionidae). Eight concentrations of essential oils (from 31 ppm to 669 ppm) were used for contact toxicity with five replications. Mortality was recorded after 24 hours. The LC5 and the LC100 of each<br>essential oil were determinated. These values were used as boundaries of the experimental matrices 23 and 22 which were used to determine the maximum synergetic effect of combinations of essential oils. It was found that the essential oil of O. canum was the most efficient (LC100 = 68ppm) while V. heterophylla essential oil was the least efficient one (LC100 = 669 ppm). According to the combinations, it was found that the mixture of the three essential oils at their LC5 level induced 87.5% of mortality whereas the expected mortality was 5 %. ...
2017
Insect pests cause damage to stored grains and processed products by reducing their dry weight and nutritional value. The control of rice weevil infestations has been primarily through the use of fumigants and residual chemical insecticides to augment the more obvious approach of hygiene. Treatment of rice with synthetic insecticides is not recommended because of direct and indirect health hazards to humans. Recognition of such detrimental effects of synthetic insecticides has prompted the development of new alternatives as less obtrusive management strategies that must be ecologically safer with no residual and noxious effects on non-target animals. Plant based formulations are chiefly biodegradable and are recognized as better sustainable and eco-friendly alternatives of synthetic pesticides in food security as their activity may be due to synergistic effects of different active principles leading to different mode of action during their pesticidal action. Therefore, in the presen...
TOXICITY OF SELECTED MEDICINAL PLANTS EXTRACTS AGAINST RICE WEEVILS
Many medicinal plants have been used traditionally to control a wide range of ectoparasites, pest insects and vectors of different diseases and for the treatment of many human diseases. This study aimed to understand the toxicity and larvicidal activity of Annona squamosa and Guaiacum officinale extracts against Sitophilus zeamais. Results of different experiments confirmed the higher efficacy of plant extracts. Lower doses of Guaiacum officinale caused 19.00% mortality while 72.00% mortality was recorded under higher doses. Similarly under the toxic effects of Annona squamosa 36.00% mortality was recorded under lower doses while 100.00% mortality was recorded under higher doses.
International Journal of Tropical Insect Science, 2020
Plant essential oils contained secondary metabolite chemicals showing toxicities on stored grain insects. The main aims of this study was to evaluate the insecticidal efficacies and chemical compositions of essential oil from C. flexuosus, C. winterianus, C. martini, and P. cablin against Sitophilus oryzae (L.). The GC-MS analysis results showed that, the essential oils of four aromatic plants are rich in citral, neral, geranyl acetate, geraniol, citronellal, geraniol, citronellol, photocitral B, azulene and αguaiene respectively. The essential oils of C. flexuosus with LC 50 values are 44.5 and 26.1 μl/L air after 24 and 48 h exposure which was found to be most potent fumigant than C. winterianus followed by C. martini and P. cablin respectively. Further, in contact toxicity, C. martini oil being the most effective against adults of S. oryzae with LC 50 values of 2.6 and 1.8 μl/cm 2 after 24 and 48 h exposure respectively, whereas moderate toxicity was observed in S. oryzae from the essential oils of C. winterianus and P. cablin. These results suggested that the essential oils extracted from C. flexuosus, C. winterianus, C. martini, and P. cablin can be used as in the management of S. oryzae in order to decrease the harmful effects and risk of synthetic insecticides on human beings. Keywords Cymbopogon species. Pogostemon cablin. Essential oils. GC-MS. Insecticidal efficacy. Sitophilus oryzae Key messages • Evaluated the insecticidal efficacy and chemical composition of essential oils from Cymbopogon flexuosus, Cymbopogon winterianus, Cymbopogon martini, and Pogostemon cablin • The essential oils of C. flexuosus and C. martini exhibited potent fumigant and contact toxicities against Sitophilus oryzae • The essential oils were found to be a potent bio-fumigant and contact toxicity to stored grain pests instead of synthetic fumigant and insecticides * Yallappa Rajashekar
Sitophilus oryzae L. is cosidered primary pest of stored grains of warm climatic areas. In the present study, ethanol extract of Psidium guajava, Citrus reticulata, Citrus limon, Citrus sinensus and Azadirachta indica were evaluated for their repellent affects against rice weevil, S. oryzae L. Four concentration viz., 5% and 10%, 15% and 20% were used. For all treatments, repellent effects increased in dose dependent manner. Our results indicated that P. guajava was most effective while A. indica as least effective among all tested treatments. Other plat materials viz., C. reticulata, C. limon and C. sinensus recorded moderate effects that did not varied significantly. This may be due to presence of same bioactive compound in plants of same genus. So it was concluded all tested plants could be incorporated in IPM programs for the effective control of S. oryzae L.
Tropical medicinal plant extracts against rice weevil, Sitophilus oryzae L
Journal of Medicinal Plants Research, 2011
Rice weevil, Sitophilus oryzae L. is one of the major pests of stored commodities, the adult weevils feed on rice and the females lay eggs inside rice kernels. In the study chemical composition of extracts from black pepper, Piper nigrum L. and physic nut, Jatropha curcas L. were tested against this pest, under laboratory conditions. The chemical compositions of the extracts were identified by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). The major extracted components of P. nigrum were piperine (74.34%) and caryophyllene (18.53%), and for J. curcas were oleic acid (40.67%), linoleic acid (34.17%) and palmitic acid (18.03%). The mortality of adults increased with increasing concentration of extracts from 2 to 10 μl/g of rice and exposure time from 24 to 72 h. The petroleum ether (LC50=1.61 μl/g) and chloroform extracts (LC50=1.70 μl/g) of P. nigrum showed higher mortality rate compared to petroleum ether extracts (LC50=6.82 μl/g) of J. curcas with 99.56, ...
TOXICITY AND REPELLENCY OF ESSENTIAL OILS AGAINST RICE WEEVIL SITOPHILUS ORYZAE (L
Indian Journal of Entomology, 2019
Contact, fumigant, persistence toxicities and repellant activity of three plant essential oils viz., cinnamon (Cinnamomum verum J. Presl), eucalyptus (Eucalyptus obliqua L'Her) and orange oil (Citrus sinensis L.) against rice weevil, Sitophilus oryzae L. were evaluated under laboratory condition. Chemical profiling of tested essential oils through GC-MS studies showed presence of various chemical constituents wherein, eugenol (82.68%), eucalyptol (64.80%) and D-limonene (83.35%) were the major component of cinnamon, eucalyptus and orange oils, respectively. Contact toxicity results indicated that at 120 hours after treatment (HAT), eucalyptus oil caused significantly maximum mortality (100%) of S. oryzae when treated with 0.75 µl/cm 2 concentration in comparison to fumigant toxicity (83%) at 2 µl/500 cm 3 concentration. The present study demonstrated that among the treated oils, eucalyptus oil has higher contact, fumigant and repellent toxicity and hence it can be harnessed for integrated management of S. oryzae under storage condition.
A study of residual toxicity of some plant extracts on rice weevil
2020
The rice weevil Sitophilus oryzae attacks mostly stored grains like wheat, maize and rice. Both the adult and larval stages destroy the grain by boring into it and reducing it to husk. The grain loss is huge therefore an eco-friendly approach to control the pest is needed. Plant products are a good solution. Seed extracts of Annona squamosa, Glycine max, Ricinus communis and Helianthus annus were used for control of pest. In the evaluation of residual toxicity it was observed that the seed extract of sunflower (Helianthus annus) was most effective and protects the wheat grain up to 90 days of treatment (90 DAT).
Asian Journal of Agricultural Sciences, 2014
Aim of the present study was to evaluate powders and aqueous extracts of Melia azedarach, Mentha piperita, Phytolacca dodecandra, Schinus molle and Xanthium strumarium leaves against maize weevil Sitophilus zeamais. Repellent activity of plant powders were evaluated by mixing 0.625, 1.25, 2.5, 5 and 10 g of powder per 100 g of clean uninfested maize seeds individually in separate plastic container. The numbers of insects moving outside the container were recorded at 24 h and 48 h post exposure period and percentage of repellent activity was calculated. The insect mortality was recorded at 5 days, 10 days and 15 days post exposure period and percentage of insect mortality was calculated. In addition, aqueous solutions were prepared by mixing 0.0625, 0.125, 0.25, 0.5 and 1 g of plant powder with 10 mL of water and tested for their insecticidal activity by topical application method. Total numbers of dead insects were counted for every 24 h up to 96 h post exposure period and percentage of insect mortality was calculated. Plant powders admixed with maize seed failed to show satisfactory level of repellent activity. Maize seed admixed with 10 g of Mentha leaf powder showed 93.3% mortality followed by Schinus (90%) and Phytolacca (90%) 5 days of post exposure period. After 15 days, 100% mortality recorded in Mentha, Melia and Schinus leaf powder mixed with 10/100 g of maize seeds followed by Phytolacca (90%) and Xanthium (86.6%). The topical application of aqueous extracts did not show insecticidal activity at satisfactory level. In general, application of Melia, Mentha and Schinus leaf powders proved to be effective against Sitophilus zeamais.
SvedbergOpen, 2021
The experiments were conducted in the laboratory of the Department of Entomology and Department of Agricultural chemistry, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during May-December 2017 to Evaluate the toxicity of five medicinal plant extracts (water hyacinth Eichhornia crassipes, swamp smartweed Polygonum coccineum, ariach Cassia tora, wild capsicum Croton bonplandianum and hill glory bower Clerodendrum viscosum) against maize weevil, Sitophilus zeamais (Mots.) on stored maize. The wild capsicum extract provided the highest average mortality (93.33±3.33), following the hill glory bower (86.67±3.33) and swamp smartweed (86.67±3.33) at 3% concentration. But it was zero in control. The average numbers of lowest numbers of adult emergence among the five weed extract were found in wild capsicum (3.00±0.39) following Swamp smartweed (5.11±0.95) at 3% concentration; whereas, in control it was (54.00±1.15). The lowest percent of seed damage was found in wild capsicum (3.00±0.38%) following Swamp smartweed (4.22±0.58). But in control, it was 44.00±1.15.Repellency class of different plant extracts at different concentration level varied between I to IV. But the hill glory bower at 3.0% showed statistically best as it showed the highest repellency rate was 66.0±5.31% and the group were IV. However, the toxicity order was wild capsicum >swamp smartweed> hill glory bower> water hyacinth>, ariach.