scholarly journals Effect of Tasmanian blue gum (Eucalyptus globulus Labill.) leaf extract on cowpea weevil (Callosobruchus maculatus [Fabricius, 1775], Coleoptera: Chrysomelidae)

2020 ◽  
Vol 116 (2) ◽  
pp. 351
Author(s):  
Samuel Femi BABATUNDE ◽  
Abdulrasak Kannike MUSA

<div class="WordSection1"><p>A laboratory study was carried out to examine the efficacy of solvent extract of <em>Eucalyptus globulus</em> leaves in reducing post-harvest losses caused by cowpea weevil<em> </em>(<em>Callosobruchus maculatus</em>) on cowpea seed variety RSH 256. 450 g of <em>E. globulus </em>leaf powder were put in 1000 ml flask and 450 ml of n-hexane was used as the solvent. The extract was tested at dosages of 50, 100 and 150 µl 50 g<sup>-1</sup> of cowpea grains on the weevil in stored cowpea. The different rates of treatment recorded significant differences (<em>p</em> &lt; 0.05) in causing adult mortality compared to the untreated control. The different rates of treatment also recorded significant differences (<em>p</em> &lt; 0.05) in emergence of F1 adults of each treatment compared to the control. The percentage masst loss and grain damage were also suppressed as a result of treatment with the plant material compared to the untreated control. However, among the treatments 150 µl 150 g<sup>-1</sup> cowpea recorded the highest adult mortality rate and lowest emergence while control had the lowest mortality rate and the highest emergence of the insect. The rates of application were indicative of bioactive characteristics of the plant extract.<strong></strong></p></div>

2015 ◽  
Vol 4 (5) ◽  
pp. 215-221
Author(s):  
Ablaye Faye ◽  
Malick Sarr ◽  
Abdoulaye Samb ◽  
Cheikh Thiaw ◽  
Mbacké Sembène

  The effect of neem leaves has been tested in the laboratory on eggs and adults of cowpea weevil (C. maculatus). Different formulations of this plant were applied to these forms of C. maculatus Fab. Grinding fresh contact sheets induced significant lethal effects from 96.12% to 100% on eggs; whereas 100% of mortality was recorded at the end of eight days of applica-tion to three adults with higher doses. Fumigation on turn proved less effec-tive than contact on eggs. It induced a maximal effect of 95.73% mortality with the larger dose (D4: 0.02912g/cm3). On adults, we recorded highest mortality (100%) from the 7th day of the show with the highest dose. The aqueous extract of neem leaf powder was less effective than all other formu-lations on the eggs as well as adults of this insect; with a higher mortality rate (74.99%) observed on the eggs with the application of the concentration C2. On adults we recorded a maximum effect (100% mortality) from the 13th day of the application with the highest concentration (C1). These mortalities would be related to the support of several active molecules contained in neem as established in literature.


2015 ◽  
Vol 60 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Abdulrasak Musa ◽  
Samuel Adewale

The aim of this study was to examine the insecticidal activities of powders of bitter leaf, cashew leaf, orange peel and pawpaw leaf against Callosobruchus maculatus (F.) (Coleoptera: Bruchidae). These were tested at 2.5%, 5.0% and 7.5% (w/w) for their insecticidal activities against the insect. Results showed that the ovicidal and adulticidal activities of the plant powders depended on dosages and exposure time. Mortalities of 16.28% and 18.75% were observed in bitter leaf powder applied at 7.5% (w/w) dosage within 24 and 48 hours post infestation (HPI), respectively. In grains treated with 7.5% orange peel powder, 12.50% and 16.28% mortalities were observed within 24 and 48 HPI, respectively. Each of bitter leaf and orange peel powders was significantly different (p<0.05) in causing adult mortality at the highest dosage compared with the control. Oviposition was inhibited at the highest dosage of the plant powders, but the percentage of oviposition in the lower dosages was three-fold lower than the control. The plant powders also significantly reduced progeny emergence and grain damaged by the beetle. No beetle emergence was recorded in grains treated with bitter leaf powder at 27 DPI. Adult beetles in grains treated with cashew and pawpaw leaf powders caused grain damage of 46.3-54.7% and 44.7-60.7%, respectively during the study period. There was a noteworthy decrease in insecticidal effects of the plant powders as indicated: bitter leaf > orange peel > cashew leaf > pawpaw leaf. It is recommended that incorporating these plant parts in pest management of stored products will guarantee user safety, reduce environmental pollution and suppress insect infestation.


2020 ◽  
Vol 81 (1) ◽  
Author(s):  
Kayode David Ileke ◽  
Jacobs Mobolade Adesina ◽  
Luke Chinaru Nwosu ◽  
Abimbola Olagunju

Abstract Background Powders and extracts of Piper guineense seeds and leaves were assessed for insecticidal activities against Callosobruchus maculatus in the laboratory at temperature and relative humidity of 29.6 °C and 75.9%, respectively. Bioactive compounds in P. guineense leaves and seeds were also investigated. The powders were tested at rates 1.0, 2.0 and 4.0 g/20 g cowpea seeds while extracts were tested at 1.0, 2.0 and 3.0%. Results Results of contact toxicity assay of the seed powder caused 100% adult mortality at 96 h post-treatment period whereas leaf powder evoked 90% adult mortality within the same period at concentration of 1.0 g/20 g cowpea seeds. Low adult emergence was observed on cowpea seeds treated with 1 g of seed powder with percentage adult emergence of 10.0% and inhibition rate (IR) of 97.5%. Beetle Perforation Index (BPI) obtained from treated cowpea seeds was significantly different (P < 0.05) from BPI of untreated seeds. Extracts of P. guineense seed were more toxic than seed powder. Piper guineense seed extract caused 87.5% adult mortality of C. maculatus while leaf extract caused 70.0% adult mortality within 24 h of infestation at concentration of 1%. Progeny development of C. maculatus was completely inhibited in cowpea treated with 2% and 3% leaf and seed extracts of P. guineense. β-Pinene was the most abundant active compound in P. guineense seed (55.6%) and leaf (48.4%). β-Phellandrene occurred 38.2% in seeds while Ocimene had the least value of 0.2% in seed and 0.5% in leaf. Conclusion The study showed that P. guineense seed powder and extracts were more effective than leaf powder and extract. Utilization of plant products as alternative to synthetic insecticides in protecting cowpea seeds against C. maculatus should be encouraged for enhanced food safety and security. Piper guineense is used as spice and medicine and interestingly safe for human use.


2011 ◽  
Vol 1 (3) ◽  
pp. 168-171
Author(s):  
J. M. Adesina ◽  
L. A. Afolabi ◽  
A. T. Aderibigbe

The efficacy of Senna occidentalis leaf powder against Callosobruchusmaculatus (F) on cowpea treated seeds was evaluated under ambientcondition (32±0.64°C and 68±3% R.H.) at the laboratory of AgriculturalTechnology of Rufus Giwa Polytechnic, Owo. C. maculatus was obtainedfrom Oja‐Oba market, Owo, Ondo State of Nigeria. The insects were rearedand bred in the laboratory. The cowpea seeds used for the bioassay werekept in the freezer for 15 days to eliminate infestation from the field. Theleaf powder was obtained after milling and four dosages of the powder (0.5,1.0, 1.5 and 2.0g) were separately admixed with 20g of cowpea in separatepetri dishes. Ten pairs of C. maculatus were introduced into each petri‐dish.Number of adult mortality, egg laid, percentage egg hatching, adultemergence and weight loss from each treatment were compared withcontrol treatment. It is concluded that the Senna occidentalis contains toxicproperties valuable for the control of C. maculatus.


2017 ◽  
Vol 1 ◽  
pp. 51 ◽  
Author(s):  
A. Muhammad ◽  
A. K. Bashir

The present review focuses on some major researches dealing with controlling Cowpea seed bruchid (CSB) due to Callosobruchus maculatus (Fab.) [Coleoptera: Bruchidae] by using some plant products. The objective of this review is to look in to the successes of the use of plant materials in the management of CSB especially in the tropics where bulk of the crop is cultivated and consumed. The review of available literature showed that, plants such as Neem, Azadirachta indica A. Juss; Garlic, Allium sativum (L.); West African pepper, Piper guineense Schumach; drum stick, Moringa oleifera Lam; African Basil, Ocimum gratissimum (L.); Moss plant; Barbula indica and Clausena anisata (Willd.) Hook has been used in CSB control. Available literatures showed that garlic, chilies and peppermint applied at the rate of 0.035–0.55g significantly (p≤0.05) reduced oviposition, respectively compared to the control. Similarly, powdered flowers of M. oleifera applied at the rate of 0.5 g per 30 g of seeds caused mortality of CSB better than the control 8 hours after infestation. The use of C. anisata and Permethrin showed percentage mortality of cowpea bruchids was high using Permethrin but was not significantly (p≥0.05) better than Clausena leaf powder. Groundnut oil applied at ˂ 4mls kg-1 does not affect germination process of cowpea stored for up to 12 weeks. However, increasing rate of application decreases germination. The review clearly indicated that plant products have potentials of controlling CSB in stored cowpea as they are safe and free from residue. They are hereby encouraged.


2021 ◽  
Vol 117 (3) ◽  
pp. 1
Author(s):  
Tosin Damilola OJUYEMI ◽  
Robert Omotayo UDDIN II ◽  
Gbonjubola Victoria AWOLOLA ◽  
Suleiman MUSTAPHA ◽  
AbdRahaman Adebowale LAWAL

<p>The study investigated the effectiveness of <em>Prosopis africana</em> and <em>Ficus mucoso</em> ethanolic leave extract in the control of <em>Callosobruchus maculatus</em> infesting cowpea. Treatments were applied at different concentrations (10 %, 30 % , 50 %, and 0 %) on cowpea. Five pairs of newly emerged adult <em>C. maculatus</em> were introduced into each treatment. The two botanicals were evaluated on the insecticidal effects it has on the insect and data were recorded on adult mortality, oviposition rate, larvae, pupae, and adult emergence, seed viability, and phytochemicals present in both botanicals. Results revealed that both treatments had insecticidal potentials, adversely reducing the number of eggs, larvae, and pupae of <em>C. maculatus</em> with <em>P. africana</em> having the highest mean mortality rate at 50 % concentration. Observations further indicated that the botanicals had no negative effect on seed viability. The phytochemical analysis revealed the presence of some bioactive compounds such as terpenoids, flavonoids, alkaloids, saponin, steroids, and tannin, <em>P. africana</em> mostly rich in them than <em>F. mucoso</em>. Though both extracts were effective, <em>P. africana</em> performed better in the control of the bruchid beetle indicating plausible usefulness in sustainable pest management by smallholder farmers and consumers of cowpea in environments where the plants are in abundance.</p>


2020 ◽  
Vol 8 (8) ◽  
pp. 262-270
Author(s):  
Chukwunonso O. Nzelu ◽  
Kingsley C. Emeasor ◽  
Nnaemeka J. Okonkwo

Post-harvest losses due to insect pest infestation in storage constitute a challenge to sustainable food security and economic losses to farmers throughout the world. Use of synthetic chemicals have been the most effective means of reducing losses in storage. Unfortunately, these toxicants have adverse effects in humans and the environment. There is renewed search for safer plant products as alternatives. In this study, we assessed the potential use of Piper guineense seed oil in the control of cowpea bruchid, Callosobruchus maculatus (F.) infestation on stored cowpea seeds. Adult mortality, oviposition rate, F1 progeny emergence, cowpea seed damage and seed germinability were the indices considered in the assessment under laboratory conditions. The setup of the experiment was completely randomized design (CRD). Statistical analysis of the data was by analysis of variance (ANOVA). Adult C. maculatus mortality was dose-dependent with higher dosages inducing 100% mortality. The number of eggs laid on the treated seeds were significantly (P<0.001) reduced. Progeny emergence and feeding damage were completely inhibited at higher dosages. The seed oil has no adverse effect on cowpea seed viability. The results indicated that P. guineense seed oil has protectant potential against insect pest damage in storage and a good alternative to synthetic insecticides in the control of insect pest of stored products.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Olufunmilayo E. Ajayi ◽  
Arthur G. Appel ◽  
Henry Y. Fadamiro

The fumigant toxicity of eight essential oil components, 1-8-cineole, carvacrol, eugenol, (−)-menthone, (−)-linalool, S-(−)-limonene, (−)-β-pinene, and (+)-α-pinene, was tested against the cowpea weevil, Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae), at 0.25–60 µL/L air doses. 1-8-Cineole, carvacrol, and eugenol caused complete adult mortality at 10 µL/L air 24 h after treatment. 1-8-Cineole and carvacrol were the most toxic with LD50 values of 0.24 and 0.6 µL/L air at 24 h, respectively. (−)-β-Pinene and (+)-α-pinene were the least toxic with LD50 values of 31 and 31.4 µL/L air at 24 h, respectively. Toxicity was negatively correlated with vapor pressure. 1-8-Cineole and carvacrol caused 100% oviposition deterrence at all doses tested. Eugenol and (−)-menthone completely inhibited adult emergence. S-(−)-Limonene, (−)-β-pinene, and (+)-α-pinene were not effective at preventing oviposition or adult emergence, suggesting that a lethal dose of the three oil components would be necessary to control C. maculatus infestations.


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