Effect of Tulsi and Neem Extract on Mosquito Larvae

Effect of Tulsi and margosa Extr operate on Mosquito LarvaeResearch interviewWhat argon the makes of medicinal kit and caboodles like Ocimum sanctum (tulsi) and Azadirachta indica (neem) state on the deathrate rate of Culex larvae?ABSTRACTThe effect of arishth and Tulsi on mosquito larvae. The project is aimed at finding natural curse wordicides or bio- curse wordicides that usefully control the mosquito existence by killing mosquito larvae. They could be employ as alternatives to the current pesticides utilise that scram a bun in the oven adverse set up on the environment and other species besides the target pest. Mosquitoes are hosts for a actually huge morsel of diseases and therefore keeping larvae below control and disallowing the emergence of adult mosquitoes is essential. Two specify conjures suck been tested margosa and Tulsi. The initial hypothesis was that both recites would have well-nigh effect on the larval development and cause death rate in the larvae due to the properties of both plants. The secondary initial hypothesis was that Neem suck out would be importantly more effective in killing the larvae than Tulsi at the same percentage. Concentrations of 1% to 10% of each extract were prepared and 10 trials each per multifariousnessed with 10 larvae were undertaken. The samples were chequered on later on 12 hours and once again after 24 hours and the number of larvae killed in each case was enter. The results were conclusive and both extracts were very effective at killing larvae at 10% with Neem killing an average of 10 larvae out of 10 and Tulsi 9.6 0.52. However t- encourages showed that the initial hypothesis stating that Neem would be more effective at all concentrations was incorrect and only 2%, 9% and 10% were importantly more effective in 24 hours with t regard ass of 3.13, 2.92 and 2.43 respectively ( table place of 2.10). This means that in 2%, 9% and 10% concentrations, Neem should be use instead of Tulsi as it is squarely better. This is all very exciting as environmentally gumshoer pesticides can be developed from these two plant extracts.1. IntroductionResearch questionWhat are the effectuate of medicinal plants like Ocimum sanctum (tulsi) and Azadirachta indica (neem) extract on the mortality of Culex larvae?The conservative pesticides are augmented to combat complicated pest problems in mosquitoes. In human health during the past few decades these pesticides played an important role in the inhibition of diseases caused by mosquitoes either by inactivating or killing these mosquitoes. Later on when these pesticides are getting accumulated in the environment proved to be hazardous to the environment and mankind. Frequent application of celluloidal organic insecticides resulted into pest resistance and outbreak. Most of the insecticidal compound falls within four main classes namely organochlorides, organophosphates, carbamates and pyrethroids. Out of these the major cla sses of insecticides, the insecticides used in reconcile situation are organophosphates and carbamates. There are problems of pesticides resistance and negative impacts on non-target organisms including man and the environment.1Environment problems due to the insecticides and pesticides such as destruction of beneficial organisms, non-target pest, some of the pesticide residues in the host plant resulting in stunted grow or killing other organisms have come to an end. This work is basically taken up by some of the herbal plants. These herbal plants possess some of the active ingredients which are eco-friendly further simultaneously have a severe effect on the mosquito populations.2Medicinal plants are the most promising source and under extensive trails for their biological activity against mingled(a) mosquito larvae. During the last 10 to 15 years, interest in botanical insecticides has increased to look for substitutions for synthetic insecticides with those establish on natur ally occurring substances. The use of botanicals in pest management is not only useful for downsizing of pest population but also alleviates to maintain the sound ecological balance.3BOTANICALS IN USEThe groups of plant possessing insecticidal substances are enormous. More than 2400 species of the plants in India possess insecticidal properties3. In the middle of the 17th century, most of the economically important natural plant compounds obtained from the plants like neem, tulsi, adathoda, chrysanthemum, turmeric, garlic, tridax etc. are used in commercial insect control. patronage the relative safety of the well-known botanical insecticides, most of these substances have their drawback hindering large-scale application. The chemicals obtained from these plants are unstable in the sun and are rapidly metabolized olibanum limiting their potency and application.4Botanical insecticides break down readily in soil and are not stored in animal and plant tissue. Often their effects are not as long lasting as those of synthetic insecticides and some of these products may be very difficult to find. The plant parts used for extraction or assay were the leaves, roots, tubers, fruits, sows, flowers, the whole plant, bark, sap, pods and wood. The most commonly utilized parts were the leaves, roots. The plant families Asteraceae, Fabaceae and Euphorbiaceae contain most of the insecticidal plant species reported. belatedly several other plants viz. Neem, Adathoda, Chrysanthemum, Turmeric, Onion, Garlic, Ocimum, Ginger and some other plants have been reported as insecticidal plants which can be used in insecticide preparation. The flip-flop extracts of Tulsi (Ocimum basilicum, O. sanctum) and vetiver (Vetivera zizanoides) are useful in controlling leaf miners in potato, beans, eggplant, tomato, chilies, etc. Some of the plants having herbal insecticide principles are presented on table.Source of Plant genius of action Chemical Group Plant parts Azadirachta indica Cont act poison Azadirachtin Leaves, actualised Ocimum sanctum Contact, Repellent Tulsin Leaves Chrysanthemum Contact, Repellent Pyrethrin I Flower, seed Tridax procumbens Contact poison Flower Zingiber officinale Repellent zingibereneRhizomeAmong all the important insecticidal plants, Neem (Azadirachta indica) is the most promising source of bio-pesticide and its various formulations are extensively used for pest control.5 Neem leaves, stems, seeds and oil have been used for pest control in sericulture.6 The limonoids present in it and its products have made it a sinless to mankind while functioning as insecticide, bactericide, fungicide, pesticide etc. It is likely to provide a settlement to many of pest and disease problem in sericulture.7 Generally, extracts of plant leaves or seed are prepared and sprayed otherwise, seeds are dried under sunshade, powdered finely and applied as dust.More than 20 Neem based biopesticides are available in the market (Table 3). Neem gets biodegraded in a matter of weeks when exposed to sunlight or in soil. Neem products are extremely photodegradable and normally degrade within a week. zero(prenominal)problem of development of pest resistance and resurgence has been reported from neem products. Hence they have characteristics sufficient for IPM strategy. Much of the informations are available on insecticidal properties of plants having some sort of toxic property against insects. The plant parts to be used should be removable leaves, flowers or fruit and harvesting should not mean destruction of the plant.Azadirachta indicaNeem is perhaps the most well known of all herbs and has been used in ayurveda in India for centuries. The active ingredient in Azadirachta indica (neem) is azadirachtin. It a member of the Meliaceae family and is a botanical cousin of mahogany. Neem is very hard and virile. Neem is curiously useful due to its climatic tolerance that allows it to be grown all over the world though it is usually found in t ropical regions. It has insecticidal, antifeedant, process regulating and development-modifying properties and has properties that make it attractive in insect control. It reduces fecundity and longevity as well as increased development time of immature insects. On insects it has been shown to act as a growth retardant and cause molting disorders, change of behavior and morphogenetic defects. Mosquito control is essential as they act as carriers for malaria, filariasis and a host of other diseases as well as being a nuisance. There is a high demand for a less environmentally libellous insecticide as the unitarys currently used have high neurotoxic effects. Recent studies have also demonstrated neem-induced effects on vitellogenesis and severe degeneracy of follicle cells during oogenesis in mosquitoes. It also has several medical properties such as a recover blood morbidity, biliary afflictions, itching, skin ulcers, burning sensations and pthysis. It is also an effective cure against ringworm, eczema and scabies. In English the tree is known as margosa and attains a maximum height of 40 to 50 metres.Ocimum SanctumTulsi is an aromatic plant in the Lamiaceae family. Tulsi has been used for thousands of years in Ayurveda due to its diverse healing properties. Tulsis extracts are used in ayurvedic remedies for common colds, headaches, bear disorders, inflammation, heart disease, various forms of poisoning, and malaria. Traditionally, tulsi is taken in many forms as herbal tea, dried powder, fresh leaf, or mixed with ghee. Essential oil extracted from Karpoora Tulsi is mostly used for medicinal purposes and in herbal cosmetics, and is widely used in skin preparations due to its anti-bacterial activity. For centuries, the dried leaves of Tulsi have been mixed with stored grains to repel insects.8These plants in harmonious integration with other safe methods of pest control like biological control can provide eco-friendly and economically viable closures for pest problems in near future.ADVANTAGESPlants producing the compounds having insect growth regulators (IGR), sustenance deterrents, repellents and confusants activities are known by the farmer because most of the time they grow in the same general area. Some of these products may be these products act very quickly inhibiting insect feeding even though long term they do not cause insect death. Since most of these products have a stomach action and are rapidly decomposed they may be more selective to insect pests and less aggressive with natural enemies. Most of these compounds are not phytotoxic and have rapid action and low toxicity to mammals and plants. Resistance to these compounds is not developed as quickly as with synthetic insecticides.DISADVANTAGESMost of these products are not sincerely insecticides since many are merely insect deterrents and their effect is slow. They are rapidly degraded by UV light so that their residual action is minuscule and breakdown is rapid, req uiring more precise timing of and/or more frequent application. Not all plant insecticides are less toxic to other animals than the synthetic ones. They are not necessarily available and sometimes cost is more. Most of them have no established residue tolerances and there is lack of test information and sometimes lack of state registration of some materials. There are no legal registrations establishing their use. Not all recommendations followed by growers have been scientifically verified. The to a higher(prenominal) place statements are altered if you find anything that can be added or deleted you can do it.Insects adapt themselves to aquatic habitats inspite of their terrestrial origin. The aquatic and semi-aquatic insects are remarkable for their miscellanea of forms, reflecting adaptation to a wide variety of niches such as salt pissing pools, saline ponds, hot springs, high mountain lakes, large rivers, temporary and permanent ponds.Mosquitoes are known as vectors of the pathogens do human diseases. They belong to the order Diptera the true flies. Like all flies they have two wing but unlike other flies they have scales and the females have sucking proboscis. There are over 2500 species of mosquitoes. Culex mosquitoes are known to be untellable and persistent biters and are a nuisance.The reason why I chose this topic is because the pesticides that are currently used in pest control contain chemicals that have diverse side effects on the environment and organisms other than the target pest. I decided to use natural substances found in nature and see if they would work as a form of pest control instead. I have used two extracts Neem and Tulsi, in order to see which one was more effective in killing these mosquitoes. Neem, Tulsi and eucalyptus have been used as they are prevalent in the tropical and sub-tropical countries of Africa and Asia with a large mosquito population and there have been strong prospects of being used as an insecticide on a commercial scale due to their useful properties.AimIn early literature mentioned above it was illustrious that the mosquitoes inhibit both temporary and fresh water stagnant bodies and they are found in abundance ca use nuisance to the human population. The aim of the present study was undertaken on the following aspects1. To determine the number of Culex larvae killed in 12 hours and 24 hours exploitation unalike plant extracts like Neem and Tulsi in crude form.2. To determine the number of Culex larvae killed in 12 hours and 24 hours by Neem and Tulsi under various concentrations (1%-10%).3. To determine the statistical analysis t tests were performed.2. Materials and Method2.1. Materials / Equipments250 ml beaker, Mortar and pestle, Pipette, Stirrer, Water, Fishing net (for catching larvae), Dropper, Watch glass, Petri dishes.Culex larvaeFor the present study, the larvae of Culex mosquitoes were used throughout the investigation. These larvae were chosen because they were mos t abundant in the water bodies which are very active fast wriggling movement. The Culex larvae were collected from stagnant water bodies at Varthur Lake in Bangalore (fig.1) employ a hand net. They were transported in plastic buckets containing clean water to the lab. Larvae were categorized based on their size as large and small. The large sized Culex larvae were about 0.7 cm and the small sized Culex larvae measured about 0.2cm in length. For the present study I have used only large sized larvae (3rd and 4th instars stage).Medicinal plants used as extractsBotanical nameCommon nameMedical PurposesPart of plant usedOcimum sanctumTulsiUsed to treat digestive problemsYoung leavesAzadirachta indicaNeemKills pathogens. Used to cure skin ailments.Young leavesPreparation of gestate rootAzadirachta indica NeemI collected neem leaves from my indoctrinate campus. Only young leaves were collected and dried in the absence of sunlight in the swart region. The complete method of preparing 1 0% phone line solution of this plant extract is mentioned below. 10 grams of dried young leaves were then grinded using mortar and pestle along with methanol and dried. Then add 100 ml of distilled water to make out 10% stock solution. Then the 10% neem stock solution was decanted after centrifugation. Now from this 10% stock solution several(predicate) concentration solutions in percentage were prepared ranging from 1% 10% i.e., 10ml of 10% stock solution in 90ml of distilled water gives 1%, 20ml of 10% stock solution in 80ml of distilled water will give 2%, 30ml of 10% stock solution in 70ml of distilled water will give 3%, 40ml of 10% stock solution in 60ml of distilled water will give 4%, 50ml of 10% stock solution in 50ml of distilled water will give 5%, 60ml of 10% stock solution in 40ml of distilled water will give 6%, 70ml of 10% stock solution in 30ml of distilled water will give 7%, 80ml of 10% stock solution in 20ml of distilled water will give 8%, 90ml of 10% stock so lution in 10ml of distilled water will give 9%, and for 10% the stock solution itself was used.Ocimum sanctum TulsiI collected Tulsi leaves from my school campus. Only young leaves were collected and dried in the absence of sunlight in the shady region. The complete method of preparing 10% stock solution and the divers(prenominal) concentration of this plant extracts in percentage was done by same method as mentioned above in Neem.2.2. Method / Procedure mortality of larvae using crude plant extracts1. The large sized Culex larvae were taken in the petridishes.2. 5 ml of crude plant extracts of neem and tulsi were taken in the antithetical test tubes.3. 10 larvae were introduced in each test tube at the same time.4. Ten trails were carried out for the two diametrical plant extract.5. The number of larvae killed was recorded for 1hr, 12hr and 24 hr.6. Larvae were feed with dog biscuit powder.7. Comparative analysis was carried out graphically between the two plant extracts at diff erent time period.Mortality of larvae using different concentration of plant extracts1. The large sized Culex larvae were collected and separated in the petri dishes.2. 5 ml of 1% Neem extract was pipetted in the test tube using a graduated pipette.3. 10 Culex larvae were introduced and the time was noted.4. Ten trials were carried out at the same time for different concentration.5. The larval mortality was recorded for 12 hours and 24 hours.6. The same procedure was followed for different concentrations 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% 10% of the Neem extract.7. During this experiment the larvae was feed with dog biscuits in powdered form.8. The above mentioned procedure was also carried out using Tulsi plant extract.9. A comparative study of larval mortality was made by using these two plants extract on the Culex mosquito larvae.The percentage of mortality (which will give us an indication of the effectiveness of the extract) will be calculated using the following formula.Percenta ge of mortality = design of dead larvaeNumber of larvae introduced X 1002.3. VariablesDependant variable- Number of larvae killedIndependent variable-Different concentration of neem extract and tulsi extract, different time period 1hr, 12 hrs, 24 hrsControlled variable-Number of larvae, Volume of water, Temperature, food2.4. HypothesisHypothesis 1 zero point Hypothesis (Ho) Neem and Tulsi have no significant the mortality of the Culex larvae.Positive hypothesis (H1) Neem and Tulsi have a significant effect on the mortality of the Culex larvae.Hypothesis 2Null Hypothesis (Ho) There is no significant difference in the rate of mortality between Neem and Tulsi plant extracts.Positive Hypothesis (H1) There is a significant difference in the rate of mortality between Neem and Tulsi plant extracts.3. Results5.1 Mortality of larvae using crude plant extractsThe Culex larvae were exposed to different plant extracts in crude form to study the mortality rate. The number of Culex larvae killed was recorded after 1 hour, 12 hours and 24 hours separately (Table 1).In one hour the mean number of larvae killed by Neem was 4.90.74 and for Tulsi it was 3.51.08. As time progresses the difference in effectiveness becomes less and the two extracts are approximately equal. The crude extract of Neem was more effective than Tulsi in one hour duration. At 12 hours the mean number of mosquitoes killed were 9.21.14 and 81.05 respectively. At 24 hours the Neem and Tulsi extracts showed almost the same level of effectiveness with mean values of 10 and 9.70.48 respectively.The crude form of Neem extract was significantly more effective than Tulsi in killing the Culex larvae in 1 hour and 12 hours. However in 24 hours there is no significant difference in the effectiveness of Neem and Tulsi plant extracts.5.2 Mortality of larvae using different concentration of plant extracts5.2.1. NeemThe mortality of the larvae using different concentrations of Neem extract was recorded. At 1% concentra tion the mean number of larvae killed was noted to be 2.4 0.52 in 12 hours and 3.5 0.53 in 24 hours. At 10% concentration the highest mortality rate was recorded as 9.6 0.52 and 10 for 12 hours and 24 hours respectively. As the concentration of the Neem extract increased, the mortality of the larvae also steadily increased (Table 2).5.2.2. TulsiThe mortality of the mosquitoes for Tulsi extract was recorded in the same way as Neem. At 1% concentration the mean number of larvae killed was noted to be 1.8 0.63 in 12 hours and 3 0.67 in 24 hours. At 10% concentration the highest mortality rate was recorded as 8.7 0.67 and 9.6 0.52 for 12 hours and 24 hours respectively. As the concentration of the Tulsi extract increased, the mortality of the larvae also steadily increased (Table 3).Table 1 Mortality of larvae using crude plant extractTrail sNo. of larvae killed1 hour12 hours24 hoursNeemTulsiNeemTulsiNeemTulsi1521091010243106109355771010464108101054387109654109101076498101084510 910109538910101052108109Mean S.D4.90.743.51.089.21.1481.051009.70.48T- test3.382.451.96CalculationsT value=Degree of freedom = 20 -2 = 18Level of significance= 0.05Table t value = 2.10Neem and Tulsi in 1 hourCalculated T value= 4.9- 3.5 / (0.74)2 + (1.08)2 /10 = 3.38Neem and Tulsi in 12 hoursCalculated T value = 2.45Neem and Tulsi in 24 hoursCalculated T value = 1.96Graph Showing the mortality of larvae using crude plant extractTable 2 Mortality of larvae using different concentration of Neem extractsS. No.Different concentration of Neem extract %Mean No. of larvae killed12 hours24 hours11%2.4 0.523.5 0.5322%3.2 0.634.3 0.4833%3.9 0.575 0.6744%4.6 0.75.9 0.7455%5.3 0.676.4 0.766%5.8 0.427 0.6777%6.5 0.857.5 0.5388%7.4 0.528.6 0.799%8.6 0.849.8 0.421010%9.6 0.5210Graph Showing the mortality of larvae using Neem plant extractTable 3Mortality of larvae using different concentration of Tulsi extractsS. No.Different Concentrations of Tulsi ExtractMean No. of larvae K illed12 hours24 hours11%1.8 0.633 0.6722%2.6 0.73.6 0.5233%3.3 0.674.4 0.744%4.1 0.745.3 0.8255%4.8 0.795.8 0.7966%5.4 0.526.7 0.4877%6.2 0.797.4 0.788%7 0.678.1 0.5799%7.9 0.579.1 0.631010%8.7 0.679.6 0.52Graph Showing the mortality of larvae using Tulsi plant extractTable showing the comparative mean mortality of the larvae using Tulsi and Neem extractsDifferent ConcentrationsMean No. of larvae Killed in 12 hoursMean No. of larvae Killed in 24 hoursTusliNeemTulsiNeem1%1.8 0.632.4 0.523 0.673.5 0.532%2.6 0.73.2 0.633.6 0.524.3 0.483%3.3 0.673.9 0.574.4 0.75 0.674%4.1 0.744.6 0.75.3 0.825.9 0.745%4.8 0.795.3 0.675.8 0.796.4 0.76%5.4 0.525.8 0.426.7 0.487 0.677%6.2 0.796.5 0.857.4 0.77.5 0.538%7 0.677.4 0.528.1 0.578.6 0.79%7.9 0.578.6 0.849.1 0.639.8 0.4210%8.7 0.679.6 0.529.6 0.5210Graph comparing number of larvae killed using both plant extracts in 12 hoursGraph comparing number of larvae killed using both plant extracts i n 24 hoursT Values at Different concentrations of Neem and Tulsi extractConcentration of Neem and TulsiCalculated t value in 12 hoursCalculated t value in 24 hours1%2.321.852%2.143.133%2.161.964%1.551.725%1.531.806%1.891.157%0.820.368%1.491.759%2.182.9210%3.362.434. DiscussionA t-test was performed for the values obtained for the comparison of the crude extracts. The t-test values for crude Neem and Tulsi extracts are effective if seeing if Neem is significantly more effective than Tulsi in a certain time period. The calculated t value for 1 hour is 3.38. This is higher than the table t value of 2.10. Hence in 1 hour Neem is significantly more effective in killing larvae. In 12 hours the calculated t value is 2.45 and therefore we can draw the same conclusion. However in 24 hours the calculated t value in 1.96 and thus there is no significant difference in the effectiveness of Neem and Tulsi. By this point it is evident that, as far as Hypothesis 1 is concerned, that both Neem and T ulsi are effective in killing mosquito larvae. With regard to the crude extract we can say that in 1 and 12 hour periods, Neem is more significantly more effective but not in 24 hours (Hypothesis 2).T-tests were also performed to compare the significant difference in mortality of Neem and Tulsi extracts at different concentrations. Separate t-tests were performed for 12 hours and 24 hours.As seen in the tables above the t-values are significant in 12 hours for 1%, 2% and 3%. They are significant as at these concentrations the calculated t values are greater than the table t value of 2.10. It is also observed in 9% and 10% concentrations in 12 hours. In 24 hours significance is observed in 2%, 9% and 10%. What these means is that for these concentrations in their respective time periods, Neem is significantly more effective than Tulsi in killing larvae.The main effect that Azadirachta indica has on larvae is the growth regulatory effect. It is because of this property that Neem acts as an brilliant natural insecticide. Exposure of culex larvae to sub lethal doses prolongs the larval development and causes reduced pupal weight and oviposition. Neem works by intervening at several stages of the insects life. The ingredients present in Neem are approximately the same shape and structure of vital hormones for the insects. The larvae absorb these Neem compounds as if they were real hormones which blocks their endocrine systems. This leaves the insects so sonfused in brain and body that they cease to reproduce and thus the population plummets.Tulsi extract exhibits high mortality, especially during the molting process. The molting of larvae takes place under the influence of the ventral nerve cord neurosecretory cells. These cells release the tanning hormone. The extract may have an inhibiting effect on such cells. They may also act on epidermal cells that produce enzymes necessary for the circular oxidation process.Both plant extracts affect reproduction and inhib it the emergence of adult mosquitoes from their larvae. They also fall the feeding time for larvae and cause less food to be ingested. This has been noted to cause a fall in the carbohydrate levels of the larvae. A study noted that the extracts cause the amount of DNA and RNA in the larvae to fall thus suggesting that the extracts may affect nucleic acid synthesis. The feeding in the larvae may have rock-bottom due to indigestion caused by the plant extracts as they inhibit metabolic processes. 9Both Ocimum sanctum and Azadirachta indica are available easily and in large quantities. They do not require professional handling, are inexpensive and safe which makes them very valuable as pesticides. Additionally Tulsi has properties that enable it to disinfect water. The extracts could help replace harmful pesticides used such as DDT as they are safe for non target animals and do not pose residue problems but are still effective in killing larvae and suppressing the adult mosquito popu lation. In conclusion further effort should be taken to produce bio-pesticides from Neem or Tulsi as well as research to find other plants products that may be more ideal. UV rays may affect the Neem and Tulsi extracts thus reservation them ineffective so research should be done in order to find plant products that do not degrade in the presence of sunlight thus making them completely versatile.5. Summary* The findings have important implications in the practical control of mosquito larvae, especially, in a polluted aquatic environment.* Ocimum sanctum and Azadirachta indica are the two plants out of which the extracts were prepared.* Solutions of concentrations varying from 1% to 10% were prepared from the stock solution for each plant.* Each concentration was tested on 10 larvae. 10 trials were undertaken and the results were noted.* Both plants were deemed effective as far as larval mortality in concerned. Neem extract had a slightly higher mortality rate.6. Bibliography(Singh e t al. 2000, 2004). Pest management in sericulture (2000), Properties and potential of natural pesticide against sericulture pests. Publ. Zool. Soc. India. pp. 200-206(Singh and Saratchandra, 2002). An Integrated approach in pest management in sericulture, Int. J . Indust. Entomol. 5, 141-151(Baskaran and Narayanswamy, 1995) Traditional pest control. Caterpillar Publications. Tamil Nadu, India.(Casida, 1983). Development of synthetic insectide from natu ral products. Case History of pyrethroids from pyrethrins.(Schmutterer, 1990). Properties and potential of natural pesticide from Neem tree. Ann. Re