Entomotoxicant potential of powders and oil extracts of three medicinal plants in the control of Sitophilus zeamais infesting stored maize (original) (raw)
Related papers
2023
The use of synthetic chemical insecticides has proven effective in controlling insects. However, indiscriminate use is associated with a variety of health and environmental problems. Plantbased products could be an alternative for pest control because of their natural originality, low/non mammalian toxicity, biodegradability, zero residual effect and accessibility. A survey conducted in the Southern part of Volta region in Ghana collected data on plant species used as maize protectants. A total of eleven plant species were obtained. Seven out of the eleven were selected based on their availability and accessibility including lemon grass (Cymbopogon citratus), basil (Ocimum basilicum), Acheampong leaves (Chromolaena odorata), garlic (Allium sativum), Africa scent leaf (Ocimum gratissimum), guava leaves (Psidium guajava), onion (Allium cepa) for preliminary screening. Four most efficacious species (Cymbopogon citratus, Psidium guajava, Ocimum basilicum and Ocimum gratissimum) were selected for further work in the laboratory at 28±2°C, 65% RH and 12D:12L against S. zeamais. The assays were conducted by treating 50 g of maize with methanol extracts at the rates of 0.2, 0.3, 0.4 and 0.5 g/mL. Contact toxicity, repellency, effects on oviposition, development, seed damage, and weight loss were assessed. The extracts significantly (p ≥ 0.05) reduced emergence of progeny from adult weevil, eggs and immature stages. The extracts had a reproduction inhibition rate of 81–100%. The extracts protected maize against damage by S. zeamais for 12 weeks. Maximum weight loss and seed damage of 11.3% and 8.7%, were recorded compared to control with 21.4% and 24.7%, respectively. The extracts could therefore be used as alternatives for synthetic insecticides.
2016
Since botanicals still remained the most promising tool that could obviate the use of chemical insecticides, this study investigated the biotoxic effect of Acacia auriculiformis and Acalypha goddsefiana powder and oil against Sitophilus oryzae. The powder of the plants were tested at 0.0g (control), 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 2.0g dosages while their extracts were prepared at 1, 2, 3, 4 and 5% concentrations per 20g of maize seeds. Solvent control was also prepared for the oil extracts bioassay. Mortality, adult emergence, % inhibition rate and % weight loss were observed. LD50 and LC50 of the powders and oils of the two botanicals were calculated at 48 hours of application. The powders of both plants achieved complete weevil mortality within 72h of application at 2.0g and their effect was significantly (p<0.05) different from other dosages except 1.0g dosage. Also, the extracts of both plant achieved 100% insect mortality within 48h hours of application at 5%. However the ...
International Journal of Biological and Chemical Sciences, 2013
The toxicity of Azadirachta indica seed powder and leaf powders from Plectranthus glandulosus, Steganotaenia araliacea and Annona senegalensis to adult Sitophilus zeamais was determined in the laboratory. The influence of drying regime and particle size on the insecticidal efficacy of P. glandulosus and S. araliacea powders was also assessed. The seeds and leaves were either dried under shade or sunlight, pulverized until the particles passed through a 1 mm or 0.2 mm mesh-sieve. Maize grains were admixed with the powders at the rates 0, 5, 10, 20 and 40 g/kg for the assessment of mortality over a 14-d or 30-d period, as well as for population increase and damage. Within 14-d exposure, P. glandulosus powder caused the highest weevil mortality followed by A. indica. A. indica powder was by far more effective in reducing grain damage and population increase compared with all the other powders during three-month storage period. Powders from the leaves dried under shade compared with those dried under sunlight and the smaller compared with the larger particle size, caused higher weevil mortality. Neem seed powder and powdered leaves of P. glandulosus have a great potential in the protection of maize against S. zeamais infestation in subsistence storage systems.
International journal of scientific and engineering research, 2018
The major problem of food security in rural area is to reduce significantly the postharvest losses essentially due to the insects' pests. At the sight of treatments costs and especially the various damages of synthetics insecticides, news inexpensive tools quite safe repellents and antifeedants for insects, and available for small-scale farmers must be found. In this study, entomocidal activity of four leaves powders was tested against Sitophilus zeamais and Callosobruchus maculatus on stored products. PROTECT DP® insecticide was applied at recommended dose; 5g of each leaves powders were tested for 50g of crops seeds (Zea mays, Vigna unguiculata). Twenty (20) individuals at 24h old of each insect's species were introduced into each jar. The jars were covered with linen cloth and were kept outdoors during forty-five days (45) using randomized block design with four replicates. Moreover, mortality rate and F1 progeny of insects were recorded; percentages of weight loss, seeds damaged and seeds germinated were also assessed. Results obtained showed that PROTECT DP® insecticide and leaves powders used had caused significant mortality rate and allowed having high germination rate compared to the control (untreated). The percentage of weight loss and seeds damaged were significantly reduced with leaves powders compared to the control. According to F1 progeny, V. amygdalina and E. citriodora leaves powders reduced to 2.00±0.91insects and 21.25±4.15insects respectively for C. maculatus and for S. zeamais, while the control allowed having the greatest number for both cases, with 86.00±13.88insects
AWUTSerBio, 2018
The loss of market values and problem of pests in the stored grains has contributed to the problem of food security in Africa. Post-harvest losses due to Sitophilus zeamais remain an important constraint to grain storage in Africa. Also, use of chemical insecticides have increased food poisoning thus there is resurgence need of using botanical pesticides to control insect pests in the field as well as in storage. This study investigated the insecticidal effects of some botanicals (Eucalyptus camaldulensis Dehnh., Mangifera indica L., Carica papaya L. and Nicotiana tabacum L. leaves) on Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidea) F1 progeny and mortality as well as weight loss of Maize. The botanicals at varying concentrations (0.1 g, 0.5 g and 1.0 g) were applied on 500 g of maize for 3 months. All the leaf powders used exhibited insecticidal properties against Sitophilus zeamais in stored maize grains. However, they are more effective at the 1.0 g/500 g of maize grain, with Nicotiana tabacum being the most effective. At 1.0 g/500 g of maize grain, the botanicals had effect on the proximate composition of the maize grains with Mangifera indica causing a reduction in the carbohydrate content of the maize grains. The results of the experiment revealed that leaf powders of Nicotiana tabacum, Mangifera indica, Carica papaya and Eucalyptus camaldulensis have great potential to be used as pesticides against Sitophilus zeamais in stored maize grain. Therefore, these botanical powders can be used as an alternative to synthetic chemical for the control of S. zeamais.
Volatile oil composition and insecticidal activity of some local plants against Sitophilus zeamais
The essential oils from the leaves of Hyptis suaveolen, Thuja orientalis, Cymbopogon citratus, and Eucalyptus camaldunensis plants were obtained using hydrodistillation method. The oil composition were reviewed using literature and are found to have similar prominent compounds, although in different concentration. The insecticidal potential of the oils were carried out against grain pest, Sitophilus zeamais using adult mortality, adult emergence, and percentage reduction in adult emergence. The results obtained in adult mortality increases as the exposure time increases even at the lowest concentration. The four plants oil extract were able to evoked 100% mortality of adult Sitophilus zeamais at the rate of 0.1,0.2,0.3,0.4,0.5 and 1.0ml/20g of maize grains after 72 hours of post treatment. The results obtained from this study revealed that the oil extracts of these plants can be used as insecticides against S. zeamais. These plants are medicinal, biodegradable, readily available and poses no harm to man.
International Journal of Tropical Drylands
The rising rate of pest resistance, and the high expense and health risks associated with insecticide use, have become a source of public concern. This study aimed to discover and evaluate plant species used by farmers in the Volta Region to control Sitophilus zeamais (Motschulsky, 1855) and Prostephanus truncatus (Horn, 1878) in stored maize grains. In a survey, Azadirachta indica, Clausena anisata, Phyllanthus amarus, Picralima nitida, Vernonia amygdalina, Nauclea latifolia, and Momordica charantia were discovered to be grain protectants against stored insect pests. All of the plants indicated above were employed in the experiment, except for A. indica, which has a long history of being used to combat grain storage pests. The insecticidal activity of dried powders (5 and 10%) and aqueous extracts (0.1 and 0.2 g/mL) of plants against P. truncatus and S. zeamais was examined. Plant species and dose rate influenced repellency. In the V. amygdalina treatment, plant powders and methanol extracts were the most poisonous to insects. The toxicity of V. amygdalina to P. truncatus and S. zeamais was 83.3 and 86.7%, respectively, at higher concentrations of 0.2 g/mL. At 0.2 g/mL, all plant extracts exhibited a significant difference in Actellic repellent (P0.05); nevertheless, C. anisata had the highest repellent action against P. truncatus and S. zeamais, with 80.0 and 66.7%, respectively. As grains were treated with plant extracts, oviposition and egg emergence were reduced compared to the control. When embryonic stages of insects were treated with methanol extracts of botanicals, the number of adult insects decreased. These findings show that the studied plants have the potential to aid in the development of post-harvest protection technology against the principal pests of stored grains, P. truncatus and S. zeamais. As a result, farmers should use it to control P. truncatus and S. zeamais in stored maize grains.
Powders and extracts of Azadirachta indica, Zanthoxylum zanthoxyloides, Anacardium occidentale and Moringa oleifera were assessed in the laboratory at ambient temperature of 28±2oC and relative humidity of 75±5% for their insecticidal activity against Sitophilus oryzae, Oryzaephilus mercator and Ryzopertha dominica infesting paddy rice. The powders of these plants were tested against these insects at 0.4g, 0.6g, 0.8g and 1g/50g of paddy while the extracts were tested at 2%, 4%, 6% and 8% concentrations. Both the powders and extracts of these botanicals evoked a high mortality effect on the insects. Moreover, both the extracts and powders of A. indica and Z. zanthoxyloides showed greater insecticidal bustle than the powders and extracts of A. occidentale and M. oleifera as they both achieved 100% insect mortality within a short period after treatment. The extracts of these plants were also able to prevent the emergence of adult insects. S. oryzae and R. dominica were more affected with all the powders and extracts of these botanicals than O. mercator which was more vulnerable to the extracts and powders of Z. zanthoxyloides than other botanicals. Moreover, all the plants used showed a greater insecticidal effect and could be integrated into pest management system.
investigate the entomocidal flurry of Newbouldia laevis against Sitophilus oryzae and Sitophilus zeamais infesting maize grain in storage. The powders of stem and root of N. laevis were prepared at 0.1, 0.2, 0.3, 0.4 and 0.5g dosages, while their extracts were prepared at 1, 2, 3, 4 and 5% concentrations. The control experiments were also set up. None of the powders of stem and root of this plant was able to achieve complete mortality of the two insects within 96h of application, except for the root powder which was able to achieve 100% mortality of S. oryzae at 0.5g dosage only. Only the root extract at 4% was able to achieve complete weevils mortality within 96h and its effect was significantly different (p<0.05) from the extracts of the stem except at 4 and 5% concentration of stem extract. The fiducial limits showed that a lower concentration of root extract was needed to cause 50% mortality in S. zeamais (0.00-1.64 %) when compared to the concentration needed for S. oryzae (0.10-1.72 %). Both the stem and root extracts of the plant were more effective than their powders. The powders and the extracts of this plant either reduced or prevented the emergence of adult weevils and inhibit the developmental period of the insects. The powders and the extracts of N. laevis also reduced or prevented the weight loss of the treated maize grains. Therefore, with the result obtained in this research, both the powder and extract of N. laevis root and stem could go a long way in the quest of providing alternative wherewithal to the use of chemical insecticides for protecting maize grain in storage. Root extract of N. laevis could, however, offer more protection against S. oryzae and S. zeamais infesting maize grain than its stem extracts.
Dosage rates of 0.625, 1.25 and 2.5% of the leaves powder of Calpurnia aurea and Milletia ferruginea, and red and white inert dusts that were admixed with the 100 g of three resistance maize varieties were tested as protectant against maize weevils under laboratory condition. Significantly (p < 0.05) higher parental adult weevil's mortality were recorded in all treatments of integration than untreated check at almost all days (except first day) after treatment. Mortality effects of the tested integrated components were also increased both with increased dosage and days after treatment. The mortality also became 100% in all treatments of integration applied at all rates, following 12 days of treatment application likewise the positive control. All treatments of integration applied at all rates also induced significantly (P < 0.05) higher (≥ 60.31%) protection of maize grains against F1 progeny emergence, grain damage (≤ 6.67) and weight loss (≤ 1.12) by S. zeamais than negative control. Besides, 100% inhibition of F1 progeny emergence, no percent grain damage and weight loss of maize grains were also observed in all of the three treatments of integration applied at dosage of 10% likewise also for that of the positive control. Therefore, integration of the aforementioned botanicals and inert dusts with resistant varieties applied at 2.5% and above (5 and 10%) rates were potent in preventing maize grains against maize weevils attack and could be used in the management of maize weevils as ecologically sound, safe and cheap weevil's management alternatives under farmer's storage conditions.