In this survey, we experimented on the effectivity of 4 different types of repellant to driving mosquitoes. Using the logic that a stronger repellant will drive more mosquitoes, and therefore consequence in less bites, it was found that the order from strongest to weakest repellant is ‘OFF ‘ , ‘Citronella oil ‘ , ‘MOZAWAY ‘ and ‘Peppermint oil ‘ . Out of the 4 repellants, ‘OFF ‘ and ‘MOZAWAY ‘ are man-made repellants, while ‘Citronella oil ‘ and ‘Peppermint oil ‘ are natural repellants that are known to hold driving consequence on mosquitoes.
In each experiment, there will be a ‘control ‘ manus and an ‘applied ‘ manus. The ‘control ‘ manus is non applied with any of the repellant tested for each experiment whereas the ‘applied ‘ manus is the 1 with the repellant. On each manus, an country of 17cm ten 10cm is drawn out, which served as the country to be observed for any mosquito bites. Repellent was applied within the designated country.
In entire, 4 tests were conducted with each repellant and the entire figure of bites for each test in the designated country was recorded. In each tabular array, the entire figure of bites from all 4 tests is tabulated.
Finally, the per centum effectivity is so calculated from the consequence. The per centum effectivity is calculated as follow:
Percentage effectivity: 100 % – [ per centum ineffectualness ] :
=100 % – [ applied/total x 100 % ]
= [ control/ entire ten 100 % ]
The principle for this is that taking the per centum of bites when repellant is applied to be uneffective [ applied/total ] , per centum effectivity would so be taking [ control/total x 100 % ] . Higher per centum effectivity would intend that the repellant has a stronger driving consequence.
From the deliberate values of the per centum efficiencies of the assorted repellants, we can reason that ‘OFF ‘ is a stronger repellant than the remainder of the repellants tested, with a high per centum of ‘89.48 % ‘ .
This is because ‘OFF ‘ contains 25 % N, N-Diethyl-meta-toluamide ( DEET ) , which is proven to be a strong repellant compound. This is followed by the100 % Citronella oil, a known natural repellant and thirdly, ‘MOZAWAY ‘ , which contains 15 % Citronella oil. Last, Peppermint oil is the weakest repellant as reflected in table 1, where there were more bites when it was applied.
The chief attractant to mosquitoes found on homo are odours in human breath and perspiration, including C dioxide and lactic acid. In the mosquitoes ‘ olfactory system, there are different receptors to observe these smells.
DEET plants by interfering with the odorant receptors, so that mosquitoes are unable to observe their quarry through the secernment from the organic structure. This helps to do quarry ‘invisible ‘ to the mosquitoes. This is in conformity with our consequence, as when utilizing ‘OFF ‘ , we accumulated the least figure of bites, which reflects that DEET is so a really strong repellant. However, it is toxic when used in big sum. Upon research, it was besides found that 100 % protection against mosquito bites can be achieved when DEET-based repellants are used with Permethrin-treated vesture, where Permethrin is a widely used chemical in insect powder. Supporting cogent evidence included that ‘OFF ‘ emerged as the best repellant, with its consequence lasting for 5 hours. Future research can be done on finding the sum of DEET in repellant to fabricate an effectual mosquito repellant that deter mosquitoes which transmit deathly diseases, without toxic reaction when applied on the tegument. Some people may see roseolas, blisters and even seizure if excessively much DEET ( 50-75 % ) was used.
100 % Citronella Oil, holding a per centum effectivity of 55.0 % , rates as 2nd most effectual repellant in our experiment. Since effectivity of both natural repellant ( Citronella oil and Peppermint oil ) rates lower than ‘OFF ‘ , it can be argued that plant-based repellants ( Citronella and Peppermint oil ) are by and large less effectual than DEET-based merchandises ( OFF ) . [ 3 ] This is supported with a research from University of Florida that DEET concentration at 23.8 % provided 37.6minutes of protection while citronella-based lotion was merely effectual for 7.9minutes.
To be an effectual repellant, it must demo a significant grade of volatility to discourage mosquitoes. Citronella and Mentha piperita oil, being volatile liquid, vaporises easy so the odor is rapidly dispersed one time applied. However, the effectual repellant vapor concentration can non vaporize so rapidly at the surface of the tegument that it loses its effectivity. The odor from the vapor of the indispensable oil is non pleasant to the mosquito, moving as a repelling factor. With Citronella oil holding a higher effectivity per centum, it can be argued that Citronella oil has a higher volatility than Peppermint Oil and it is better at keeping surface effectivity. These consequences may explicate why Citronella oil is found in most repellants that are DEET-free. An illustration would be “ MOZAWAY ‘ which contains 15 % of Citronella oil. Further research could be done in this field to look into the consequence of 100 % Citronella oil combined with other good repelling agents so that the job of toxicity in DEET repellant can be overcome, without compromising on the effectivity of the repellant.
Last, ‘MOZAWAY ‘ was ranked 3rd effectual. It contains merely 15 % of citronella, which is considered diluted ; hence the effectivity was greatly reduced. For 100 % citronella oil, there is a demand to reapply every 30-60minutes because the volatile liquid vaporise easy. Therefore, the ‘MOZAWAY ‘ is relatively weaker as the diluted solution will evaporate faster than a 100 % Citronella Oil. This provides utile information to consumers so that they can take a higher concentration of the active natural repellant if they opt for DEET-free repellants.
- Mathias Ditzen, Maurizio Pellegrino & A ; Leslie B. Vosshall* ( 2008, March 14 ) . Chemicals Like DEET In Bug Spray Work By Dissembling Human Odors.
- DEET ( n.d. ) . In Wikipedia. Retrieved March 18, 2010, From hypertext transfer protocol: //en.wikipedia.org/wiki/DEET.
- Mark S. Fradin, MD ( 1998, June 1 ) Mosquitoes and Mosquito Repellents: A Clinician ‘s Guide.
- Permethrin ( n.d. ) . In Wikipedia. Retrieved March 18, 2010, from hypertext transfer protocol: //en.wikipedia.org/wiki/Permethrin.
- MedicineNet.com ( 2003, June 27 ) Martin Downs Mosquito Repellents: What Works. Retrieved from hypertext transfer protocol: //www.medicinenet.com/script/main/art.asp? articlekey=52165.
- ToxFAQsa„? for DEET ( 2003, August ) Retrieved March 18, 2010. Website: hypertext transfer protocol: //www.atsdr.cdc.gov/tfacts185.html.
- Katherine L. Margo ( 2002, October ) DEET is the most effectual mosquito repellant Patient. Oriented Evidence that Matters – Brief Article.