...Comparing LC50 of Insectisides Pirimicarb and Rotenone on Blowfly, Blowfly larvae, Woodlice and Daphni Abstract The LC50 of insecticides rotenone and pirimicarb were compared by testing blowfly, blowfly larva, woodlice and daphnia. Rotenone is a NADH dehydrogenase inhibitor causing death by oxidative stress however pirimicarb causes toxicity through acetylcholinesterase inhibition. It was found that rotenone had large toxic effects on daphnia, blowflies and woodlice but not maggots and pirimicarb had low toxic effects on all of the organisms tested. Due to the low percentage death caused by pirimicarb a LC50, however in rotenone a LC50 was performed for daphnia, woodlice and blowfly the LC50 for each organism was compared concluding that rotenone was most toxic to daphnia. Introduction Rotenone is a naturally occurring insecticide derived from the root of Derris Ellipitica and Lonchcarpus species (Nass &Przedborski 2008). It is metabolised in the liver by NADP-linked hepatic microsomal enzymes and is both a contact and systemic insecticide. Rotenone can be used as either a specific or a non-specific broad-spectrum insecticide that has been used since 1848 (Gupra 2012) (Nass & Przedborski 2008). Pirimicarb or Dimethyamino-5,6-dimethylpyrimidin-4-y; N,N-dimethylcarbamate is a synthetic systemic selective insecticide with contact stomach and respiratory action. Pirimicarb was first made by Imperial Chemical Industries and was originally registered in 1974 but...
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...with the boiling tubes). Start with the lowest concentration of pesticide and work upwards. The spraying of pesticide must be carried out in the fume hoods. Briefly spray the pot through the mesh netting so that the pesticide comes into contact with the flies. Before spraying make sure none of the flies are on the netting, as otherwise they will get a larger dose than those on the bottom of the container. You should also use the same procedure for each pot. Note that since there are only 11 pots, 1 pot will be the control and 5 pots will be used for each pesticide. Ensure that you use the following concentrations of rotenone (0.03, 0.1, 0.3, 1 and 3x for Rotenone) and primicarb (3 x 10-8, 3 x 10-7, 3 x 10-6, 3 x 10-5 and 3 x 10-4M for pirimicarb). It is important that you start with the control, then the most dilute solution of one of the pesticides. Work your way up to the top concentration of the pesticide, then thoroughly wash the spray top with distilled water. Then you should use the spray top to dispense control solution in order to clean the inside of the spray. Now you can move onto the most dilute solution of the 2nd pesticide and work your way up to the top concentration. When dispensing pesticide solutions it is essential that you use a new clean pipette tip for each solution to avoid cross contamination of...
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...THE CONCEPT OF PEST A pest can be defined as any organism which injures man, his property, or his environment, or which just causes him annoyance. Such organisms include principally certain insects, nematodes, fungi, weeds, birds and rodents, or any other terrestrial or aquatic plant or animal life, or virus, bacteria, etc. In agriculture, concern is normally expressed when the damage done to a crop by a specific crop pest or a group of pests causes a loss in yield or quality because this would mean a reduction in profit. When a loss in yield reaches certain proportions, the pest can be designated an economic pest. According to Edward and Heath (1964), the pest status is reached when there is a 5 percent loss in yield in a particular crop. In pest management, the economic appraisal of the pest status and justification of the need to embark on control measures is defined in relation to the following concepts: economic damage, economic injury level and economic threshold. Economic damage can be defined as the amount of injury done to a crop that will justify the cost of artificial control measures. Economic injury level is the lowest pest population density that can cause economic damage, which will vary from crop to crop, season to season, and area to area. For practical purposes, there is an economic threshold defined by Stern et al. (1959) as the pest population density at which control measures should be initiated or started to prevent an ever increasing pest population from...
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