Evaluation of the dust and methanol extracts of Garcinia kolae for the control of Callosobruchus maculatus (F.) and Sitophilus zeamais (Mots)

Evaluation of the dust and methanol extracts of Garcinia kolae for the control of Callosobruchus maculatus (F.) and Sitophilus zeamais (Mots) 1 first-author †E-mail:droluwaleye@yahoo.comadefemisamuel@yahoo.com †E-mail:droluwaleye@yahoo.comadefemisamuel@yahoo.com droluwaleye@yahoo.com 2 †E-mail:droluwaleye@yahoo.comadefemisamuel@yahoo.com †E-mail:droluwaleye@yahoo.comadefemisamuel@yahoo.com droluwaleye@yahoo.com Department of Zoology, University of Ado-Ekiti, Ado Ekiti, Ekiti State 234, Nigeria Department of Zoology, University of Ado-Ekiti, Ado Ekiti, Ekiti State 234, Nigeria Department of Chemistry, University of Ado-Ekiti, Ado Ekiti, Ekiti State 234, Nigeria Department of Chemistry, University of Ado-Ekiti, Ado Ekiti, Ekiti State 234, Nigeria Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects; none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C . maculatus and S . zeamais . The mortality of C . maculatus by the lowest concentration of methanol extracts ranged from 95%~100% whereas in S . zeamais , the mortality ranged from 87.5%~100% and 70%~100% in concentrations of 1 g extract+3 ml methanol and 1 g extract+5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract+15 ml methanol had no significant lethal effect on Sitophilus zeamais . Insecticidal effect Garcinia kolae Sitophilus zeamais Callosobruchus maculatus INTRODUCTION 1 Crop products are the end result of a sequence of husbandry operations in the field, starting from land preparation to harvesting. After harvesting, it has become necessary to store the products for some period before consumption or use for a variety of purposes that have been given by Adesuyi ( 1977 1977 ). However, in the post-harvest period, stored crop products are usually liable to depreciation by pest organisms especially insects. Most important storage pests are Coleopterans and some Lepidopterans. Varying estimates of losses caused by storage insect pests abound in literature. Appert ( 1987 1987 ) reported total crop losses (from harvesting to consumption) to be 40% of production in the hot, humid regions of the world and more than 10% in the dry regions. Estimates of post-harvest crop losses worldwide have also been given as 10%~20% but 25%~40% for the tropics by other researchers (Hill and Waller, 1990 1990 ). In storage, Callosobruchus maculatus causes a major loss. Infestation of stored cowpea could be as much as 98% in markets and in village stores (Albeek, 1996 1996 ). The magnitude of damage that can occur will depend on many factors such as the kind of crop and insect storage duration and the prevailing environmental conditions (Hill and Waller, 1990 1990 ). Delima ( 1987 1987 ) reported that insect pest problems in the tropical storage environment are greater than those in the temperate climates, presumably because of optimal conditions of temperature and humidity for pest development found in the former. Many synthetic insecticides have been reported as effective in the control of field and storage insect pests (Hill and Waller, 1990 1990 ; Obeng-Ofori and Dankwah, 2004 2004 ; Ogunleye, 2001 2001 ; 2006 2006 ; Anyim, 2003 2003 ; NFMAWR and ODABG, 1996 1996 ), but their adoption and use by most tropical farmers are hampered by several factors including prohibitive costs, inconsistent supplies of the chemical and safety of workers and consumers (Wolfson et al., 1991 1991 ; Golob et al., 1999 1999 ). Insecticides can also lead to pest resurgence. Current research focus in stored products protection includes the development of non-chemical technologies which may eliminate the use of insecticides and have economic and health benefits for the applicators, consumers and the environment (Murdock et al., 1997 1997 ; Talukder and Howse, 2000 2000 ; Elhag, 2000 2000 ). The use of more natural and sustainable methods of protecting harvested crops from insect damage is most favored (Golob et al., 1999 1999 ). A lot of successes have been recorded in this area (Ogunleye, 2000 2000 ; 2003 2003 ; 2006 2006 ; Ogunleye et al., 2003 2003 ; Omotoso and Ogunleye, 2006 2006 ; Obeng-Ofori and Dankwah, 2004 2004 ; Elhag, 2000 2000 ; Kéita et al., 2001 2001 ). This research work evaluates the possible usage of Garcinia kolae extracts and dust for the control of Sitophilus zeamais and Callosobruchus maculatus . MATERIALS AND METHODS 1 Insects culture 2 A pure culture of the two species of insects, Sitophilus zeamais and Callosobruchus maculatus , was maintained in the laboratory. Clean uninfested seeds of cowpea and maize were kept separately in Kilner jar-like containers. Twenty randomly selected species of C . maculatus and S . zeamais were placed in cowpea and maize containers, respectively. These were then left on the laboratory table under ambient environmental conditions of 32 °C and 60% RH. The insects multiplied in the containers within six weeks. All the insects used for these experiments were taken from these containers. Preparation of plant dust 2 Five kilograms of fresh, clean seeds of Garcinia kolae were purchased at the central market, Igede-Ekiti, a town located in Ekiti State, Nigeria. The seeds were then spread on the laboratory table to air dry under ambient environmental conditions of 32 °C and 50% RH. This was done for a period of two months to ensure proper drying. The seeds were thereafter pulverized using a milling machine, kept in clean plastic containers and preserved in the refrigerator to maintain its freshness. Application of plant dust 2 Twenty grams of uninfested cowpea were weighed into Petri-dishes. Into each of these dishes placed were different doses of the plant dusts, 2.5 g, 2.0 g, 1.5 g and 1.0 g, respectively. Twenty species of S . zeamais and C . maculatus were introduced into each of the cages. They were them shaken vigorously to ensure even distribution of the dust on the insects. Each of the cages was replicated three times. The control had no dust. Preparation of plant extract 2 One hundred grams of pulverised plant powder was soaked in 250 ml of methanol in a 500 ml beaker for 5 d. The mixture was shaken vigorously at 12-h intervals to ensure proper soaking of the plant product. After 5 d, decanting of the extract was done and the liquid extract was filtered using a fine cotton cloth. The filtrate was left on the laboratory table for 2 d for total evaporation of the solvent; a pure solid extract was left in the container. This weighed 10 g. It was then kept in the refrigerator. Different concentrations of the extract were prepared as follows: (1) 1 g of the extract+2 ml of methanol; (2) 1 g of the extract+3 ml of methanol; (3) 1 g of the extract+5 ml of methanol; (4) 1 g of the extract+10 ml of methanol; (5) 1 g of the extract+15 ml of methanol. Application of plant extract 2 The insect species were put in the refrigerator for 3 min to immobilize, being prevented from flying away. Twenty species of C . maculatus and S . zeamais were placed separately in Petri-dishes. Each of the prepared concentrations of the extract was applied topically at the rate of one drop on each insect. A 5 ml hypodermic syringe was used for the application. For the control, only methanol was applied on the insects. The experiment was replicated 3 times. The containers were covered with nets and left on the laboratory table. Percentage mortality of insects was taken on hourly basis. Statistical analysis 2 All data collected were subjected to analysis of variance and the means were separated, using Fisher’s least significant difference. RESULTS AND DISCUSSION 1 The results of the effects of different doses of the dust of G . kolae on C . maculatus are presented in Table 1 1 . The plant dust had no lethal effect on the insects as none of the insects died in all the treatments and the control even at 3 d post treatment. There was also a gradual increase in all the treatments as well as the control from the 4th day to the 5th day in which the experiment was terminated. The reduction in insect population at this time could be attributed to old ages. Analysis of variance showed no significant difference in all the treatment and the control. From this result, it can be deduced that G . kolae is not effective in its powder form for the control of C . maculatus . However, the highest dose, 2.5 g of the dust, recorded significantly high percentage mortality. This is a pointer to the fact that, if the dose is increased, further, it is likely to show some potency. Means followed by the same letter are not significantly different at 5% level of probability using Fisher’s least significant difference (LSD) 2 Treatment 5 Mean percentage mortality (%) Day 1 Day 2 Day 3 Day 4 Day 5 2.5 g 0±0 0±0 0±0 30.0±5.2 a 52.2±9.7 a 2.0 g 0±0 0±0 0±0 25.0±5.0 a 42.5±8.3 b 1.5 g 0±0 0±0 0±0 12.5±5.4 b 37.5±4.1 b 1.0 g 0±0 0±0 0±0 30.0±0.0 a 35.0±8.7 b Control 0±0 0±0 0±0 27.5±6.0 a 35.0±8.7 b Table 2 2 shows the result of the application of plant dust on Sitophilus zeamais for 5 d. Little or no mortality was observed on the insects in all the treatments and control for the 5 d period. Means followed by the same letter are not significantly different at 5% level of probability using Fisher’s least significant difference (LSD) 2 Treatment 5 Mean percentage mortality (%) Day 1 Day 2 Day 3 Day 4 Day 5 2.5 g 0±0 0±0 0±0 a 2.1±2.1 b 2.5±2.1 b 2.0 g 0±0 0±0 0±0 a 0±0 a 0±0 a 1.5 g 0±0 0±0 2.5±1.8 b 2.5±1.8 b 2.5±1.8 b 1.0 g 0±0 0±0 0±0 a 0±0 a 0±0 a Control 0±0 0±0 0±0 a 0±0 a 2.5±1.8 b Mortality ranged from 0% to 2.5% for all the treatments. This is a clear indication that the population of S . zeamais cannot be controlled by the dust of G . kolae . The effect of methanol extract of G . kolae on C . maculatus is presented in Table 3 3 . It was generally observed that the insects died soon after application of the extract, except the lowest concentration in which 95% mortality was recorded. All the treatments had 100% mortality after 2 h of application. It was reported that the active principles of an ideal insecticidal plant should not be poisonous to human. The plant should also be easy to cultivate through agricultural procedures. The mortality rates in the control experiment remained low with 2.5% after 2 h when the experiment was terminated. It can be deduced from this result that there are some insecticidal properties in the test plant which are not available or potent in the powder form. It can however be extracted and made available by methanol. The insecticidal plant powders may be more potent through extraction using appropriate solvent (Makanjuola, 1989 1989 ; Ogunleye, 2000 2000 ). Methanol has been used by some researchers to extract some active principles from plant materials. Methanol extracts of G . kolae , A . leiocarpus and V . donianas were tested and found to have anti-microbial effects against methicilin resistant Staphylococcus aureus , vancomycin resistant Enterocollus and muttidung-resistants Burkholderia capacia and Pseudomonas aeriginosa (Oluronke et al., 1999 1999 ). Means followed by the same letter are not significantly different at 5% level of probability using Fisher’s least significant difference (LSD) 2 Treatment 2 Mean percentage mortality (%) 1 h 2 h 1 g extract+2 ml methanol 100±0 a 100±0 a 1 g extract+3 ml methanol 100±0 a 100±0 a 1 g extract+5 ml methanol 100±0 a 100±0 a 1 g extract+10 ml methanol 100±0 a 100±0 a 1 g extract+15 ml methanol 95.0±5.0 a 100±0 a Control 2.5±4.3 b 2.5±4.3 b Table 4 4 shows the mean percentage mortality of S . zeamais treated with different concentrations of G . kolae extracts after 3 d. The highest dose of 2 ml methanol+1 g extract gave 100% mortality after 24 h. Means followed by the same letter are not significantly different at 5% level of probability using Fisher’s least significant difference (LSD) 2 Treatments 3 Mean percentage mortality (%) Day 1 Day 2 Day 3 1 g extract+2 ml methanol 100±0 a 100±0 a 100±0 a 1 g extract+3 ml methanol 87.5±4.3 a 100±0 a 100±0 a 1 g extract+5 ml methanol 70.0±7.1 a 100±0 a 100±0 a 1 g extract+10 ml methanol 0±0 b 22.5±4.3 a 97.5±4.3 a 1 g extract+15 ml methanol 0±0 b 0±0 b 15.0±5.0 b Control 0±0 b 0±0 b 0±0 b For the experiments with 1 g extract+3 ml methanol and 1 g extract+5 ml methanol, mortality ranged from 87.5%~100% and 70%~100%, respectively, from 24 h to 48 h; in the case of 1 g extract+10 ml methanol and 1 g extract+15 ml methanol, mortality of S . zeamais ranged from 0% to 100% in the two cases from the 1st day to the 4th day. The result of the control experiment measured 0% throughout the period of study. The potency of Garcinia kolae has been attributed to the presence of terpenes, steroids, coumarines, flavonoids, phenolic acid, lignins, xanthones and anthraquinones (Tona et al., 2004 2004 ). References SA Adesuyi . Preservation of grains in the tropics with special reference to Nigeria . Appl Agric , 1977 . 3 50 - 56 . . Preservation of grains in the tropics with special reference to Nigeria FV Albeek . Natural suppression of bruchid pests in stored cowpeas ( Vigna unguiculata ) (L.) Walp in West Africa . Int J Pest Manage , 1996 . 42 55 - 60 . . Natural suppression of bruchid pests in stored cowpeas (Vigna unguiculata) (L.) Walp in West Africa A Anyim . Effects of insecticidal treatment on the yield and control of the major pest of soybeans Glycine max (L. Mevill) in south Eastern Nigeria . Int J Agric Rural Dev , 2003 . 4 100 - 109 . . Effects of insecticidal treatment on the yield and control of the major pest of soybeans Glycine max (L. Mevill) in south Eastern Nigeria J Appert . The Storage of Food: Grains and Seeds , 1987 . : London Macmillan Publishers Ltd , 146 . The Storage of Food: Grains and Seeds CPF Delima . Insect pests and post-harvest problems in the tropics . Insect Sci Its Applic , 1987 . 8 673 - 676 . . Insect pests and post-harvest problems in the tropics EA Elhag . Deterrent effects of some botanical products on oviposition of the cowpea bruchid, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) . Int J Pest Manage , 2000 . 46 ( 2 ): 109 - 113 . DOI: 10.1080/096708700227462 http://doi.org/10.1080/096708700227462 . Deterrent effects of some botanical products on oviposition of the cowpea bruchid, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) PS Golob , M Moss , H Fidgen , 等 . The Use of Spices and Medicinals as Bioactive Protectant for Grains , 1999 . : Rome F.A.O , 239 . The Use of Spices and Medicinals as Bioactive Protectant for Grains DS Hill , JM Waller . Pests and Diseases of Tropical Crops , 1990 . : UK Field Handbook Longman Scientist and Technical , 432 . Pests and Diseases of Tropical Crops SM Kéita , C Vincent , JP Schout , JT Arnason , A Belanger . Efficacy of essential oil of Occimum bacilicum L. and Occimum gratissimum L. applied as an insecticidal fumigant and powder to control Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) . J Stored Prod Res , 2001 . 37 ( 4 ): 339 - 349 . 11463396 DOI: 10.1016/S0022-474X(00)00034-5 http://doi.org/10.1016/S0022-474X(00)00034-5 . Efficacy of essential oil of Occimum bacilicum L. and Occimum gratissimum L. applied as an insecticidal fumigant and powder to control Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) WA Makanjuola . Evaluation of extracts of mean ( Azadirachta indica A. Juss) for the control of some stored product pests . J Stored Prod Res , 1989 . 25 ( 4 ): 231 - 237 . DOI: 10.1016/0022-474X(89)90029-5 http://doi.org/10.1016/0022-474X(89)90029-5 . Evaluation of extracts of mean (Azadirachta indica A. Juss) for the control of some stored product pests LL Murdock , RE Shade , LW Kitch , 等 . BB Singh , FR Mohan Raji , KE Dashel , 等 . Post Harvest Storage of Cowpea in Sub-saharan Africa . Advances in Cowpea Research , 1997 . : IITA, Ibadan, Nigeria IITA/JIRCAS Publication , 302 - 312 . . Post Harvest Storage of Cowpea in Sub-saharan Africa NFMAWR and ODABG (Nigerian Federal Ministry of Agriculture and Water Resources and Overseas Development Administration of the British Government) Insect Pests of Nigerian Crops: Identification, Biology and Control , 1996 . : Chathan, UK Natural Resources Institute , 253 . Insect Pests of Nigerian Crops: Identification, Biology and Control D Obeng-Ofori , JA Dankwah . Comparative efficacies of three insecticidal materials as steam treatment for protection of Babara groundnut against ( Callosobruchus maculatus Fab) (Coleoptera: Bruchidae) . Ghana J Agric Sci , 2004 . 37 33 - 42 . . Comparative efficacies of three insecticidal materials as steam treatment for protection of Babara groundnut against (Callosobruchus maculatus Fab) (Coleoptera: Bruchidae) RF Ogunleye . Effectiveness of some plants against Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) . Appl Trop Agric , 2000 . 5 ( 1 ): 72 - 76 . . Effectiveness of some plants against Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) RF Ogunleye . Comparative effectiveness of Gamalin 20, Audrex 40 and Vetox 85 in controlling Eurema hacabe (L.) a defoliator of Parkia biglobossa . J TechnoSci , 2001 . 5 77 - 80 . . Comparative effectiveness of Gamalin 20, Audrex 40 and Vetox 85 in controlling Eurema hacabe (L.) a defoliator of Parkia biglobossa RF Ogunleye . Preservation of maize seeds with different dose of Zanthoxyhum zanthoxyloides . J Biol Phys Sci , 2003 . 2 ( 1 ): 33 - 36 . . Preservation of maize seeds with different dose of Zanthoxyhum zanthoxyloides RF Ogunleye . Comparative effectiveness of Cypermethrin and Zanthoythum zanthoxyloides (LAM) for the control of the cowpea foliage pest, Ootheca mutabilis (Salbergy) . J Ultra Sci Phys Sci , 2006 . 18 ( 1 ): 9 - 14 . . Comparative effectiveness of Cypermethrin and Zanthoythum zanthoxyloides (LAM) for the control of the cowpea foliage pest, Ootheca mutabilis (Salbergy) RF Ogunleye , CO Adedire , SA Adesuyi . Toxicity of some under utilized tropical plants to the storage pest of maize, Sitophilus zeamais (Mots) (Coleoptera: Curculionidae) . J Biol Phys Sci , 2003 . 2 ( 1 ): 22 - 27 . . Toxicity of some under utilized tropical plants to the storage pest of maize, Sitophilus zeamais (Mots) (Coleoptera: Curculionidae) T Oluronke , H Song , F Lee . Phytotherapy Research , 1999 . John Wiley & Sons, Ltd , 675 - 679 . . Phytotherapy Research OT Omotoso , RF Ogunleye . Insecticidal and antiovipositional properties of some aromatic medicinal plants of Callosobruchus maculatus . J Ultra Sci Phys Sci , 2006 . 18 ( 2 ): 181 - 186 . . Insecticidal and antiovipositional properties of some aromatic medicinal plants of Callosobruchus maculatus FA Talukder , PE Howse . Isolation of secondary compounds from aphanamidis polystachygas as feeding deterrents against adult Tribolium castaneum (Coleoptera: Tenebroidae) . J Plant Dis Prot , 2000 . 107 ( 5 ): 498 - 504 . . Isolation of secondary compounds from aphanamidis polystachygas as feeding deterrents against adult Tribolium castaneum (Coleoptera: Tenebroidae) L Tona , K Cimanga , CT Mesia , TD Mesuamba , S Apers , N Harnans , SV Vanmiert , L Pieter , J Johe , AJ Vlie Tinek . In vitro antiplasmodial activity of extracts and fractions from seven medicinal plants used in the Democratic Republic of Congo . J Ethnopharmacol , 2004 . 93 ( 1 ): 27 - 32 . 15182900 DOI: 10.1016/j.jep.2004.02.022 http://doi.org/10.1016/j.jep.2004.02.022 . In vitro antiplasmodial activity of extracts and fractions from seven medicinal plants used in the Democratic Republic of Congo JL Wolfson , RR Shade , PE Mentze , LC Murdock . Efficacy of ash for controlling infestations of Callosobruchus maculatus . J Stored Prod Res , 1991 . 27 ( 4 ): 239 - 242 . DOI: 10.1016/0022-474X(91)90006-X http://doi.org/10.1016/0022-474X(91)90006-X . Efficacy of ash for controlling infestations of Callosobruchus maculatus 10.1631/jzus.2007.B0912 2007-08-27 2007-10-18 2022-01-05 Copyright © 2007, Journal of Zhejiang University Science 2007 Journal of Zhejiang University-SCIENCE B (Biomedicine and Biotechnology) 12 08