In this study, the researchers will test theefficacy of the different concentrations of Switeniamacrophyla (Mahogany) leaves extract as a potential pesticide against Scotinophara coarctata (Black bug). Theresearchers will be discussing about Switeniamacrophyla (Mahogany) as a plant and black bugs being the subject of thisstudy. The review of this section would tackle on the different parts ofmahogany tree. Mortality rate will also be talked over in this section togetherwith the method on how to test it. Mahogany treeThe most durable and versatile wood ismahogany due to its resistance against other insects and rot, refinements to abeautiful high gleams and a cheaper wood to use as furniture.
It can be usedanywhere or for anything.Mahogany LeavesAccording to Liman (2009), the extract fromMahogany leaves may contain active substances that can be harmful and toxic tonematodes and are potentially be used as a nematicides. The leaves can be usedas an agent to which it will be mixed with soil through tilling method or byapplying the leaves directly to the “prone” crops. The study also suggest thatthe decrease in number observed in nematodes can be liable for the expansion ofgrowth of the seedlings. Such reduction means fewer disturbances to theseedlings results in an unconstrained growth. Mahogany SeedsAs for Dalisay (2014), every plants containtoxins with concentrations of WHO different-diff. It means that the higher the concentration,the higher the number of toxins WHO, with regards to the inhibition of growthand the cause of death of the insects.
The efficacy of pesticide vegetable fromplant materials have an advantage due to its active ingredients that can beharmful to pests.Mahogany BarkThe study “The efficacy of combining tubertreatment with mahogany bark aqueous extracts and exposure to solar heat forthe control of potato tuber soft rot” conductedby Bdliya (2010) test the incidenceof tuber soft rot exposed to solar heat. It showed that tuber treatment withplant extract with exposure to solar heat significantly diminish the severityand incidence of tuber soft. However, tubers treated with plant extract with noexposure to solar heat obtained the highest reduction on the severity andincidence of the disease. This explains that plant extract is effective atlower temperature.Methods of extractionAt 50 ° C, the leaves cleaned by deionizedwater, were over dried for almost 48 hours and then powdered in a grinder. Thepowdered plant (200gm) was consecutively extracted with petroleum ether,benzene, chloroform, methanol and water (2000 ml each) abiding the increasingpolarity using Soxhlet apparatus for 24 hours at a temperature not surpassingto the respective solvent’s boiling point.Using Whatmann No.
1 filter, the attained extracts were filtered. Under vacuumat 40° C, it was concentrated using arotary evaporator. The extract waspowdered using Allied Frost Iypholizer at 55° C under vacuum conditions andthen stored in refrigerator in a small and sterile bottles (Addisu, 2018).Theleaves of Mahogany were cut into pieces and air dried for about 21-28 days thenminced into powder using electric grinder. The 285 g of milled samples weresoaked in 1200 mL, 900 mL, and 750 mL analytical grade n-hexane sequentially on a magnetic stirrer.
The extracts were then filtered using filter paper or muslin cloth, after 72hrs. The use of rotary evaporator, concentrates the filtrates. Drying in anoven at 4° C and 600 mmHg was done to eliminate the solvents (Liman 2009).To obtained constant finedust particle, the dried seeds and leaves of the desired botanicals werepulverized using micro plant grinding machine and then filtered through a 0.25 mm pore size mesh seize.
Itwas then kept in a glass containers with screw cap, separately at roomtemperature in dark. 100 mL of waterwere mixed with the powder and then calculated by volume bases that ispowder/volume of water. Consecutively, the 10, 2, 10 and 35 g of the grindedplant material were soaked in a 100 mL of water. After 24 hrs, each mixturewere filtered using cheese cloth (Laxmaiah, 2011)Black BugsAccording to Laxmaiah, farmlands and ricefields are the common habitat for the Scotinpharacoarctata, commonly known as black bugs.
They were common in rained andwetland area. They emit foul odor thatcan cause itching when they come in contact with the skin. Since they are veryattracted to light, these bugs are abundant when full moon. From the seedlingup to the maturity stage of the plants, bugs suck the sap from the panicles andmidrib leaves at the milk stage, preventing the plant from growing. Since thereare removal of a large amount of sap, the effect of toxins were introduced.
Theeffect of these are; discoloration of the leaves, desiccation in the plant,dead in the upper leaves, or young leaves may fail to develop (2011).Dependent Variable Mortality RateTo assess the mortality rate of the termites,the extracts of selected botanical extracts were unified in to the regime, at10, 20, 30 and 35% concentration for each extracts (of seed and leaves) withtwo controlled group which are the following; sterile water as negative andcommercial insecticide as positive control variable. At temperature 25±3°C anda relative humidity of 60-70%, the petridishes with botanical extracts thatwere treated are strained with a filter paper, for three days. The mortality ratewas recorded during the 24 hrs interval (Fathomi, 2013). The dead and livetermites were counted and base on the equation given, percent mortality wascalculated:.The study of Ojebode, the method used toapply the different treatments are spray method. In the respective cagescontaining 10 cultured leafhoppers, 10 mL of each treatment was sprayed.
Thetotal number of cultured green leafhoppers are120 including the controlvariable since there are 3 replication for each treatments. To show the effectivenessof the plant extract, mortality rate was calculated. Through spray method, themortality rate of the green leafhoppers was determined after every 6 minutes,for a total of 30 minutes (2016).