(Aedes aegypti are the carriers of deadly yellow and dengue fever. / Jimmy Smith via Creative Commons)

Aedes aegypti, a type of mosquito that carrys the disease, was first found in June in the city of Madera, California. The mosquito bites during the day and are capable of reproducing simply by laying eggs in less than a teaspoon of water.

Despite eradication efforts to warn people of standing water that can allow these insects to lay its eggs, more mosquitoes were soon discovered in Clovis, Fowler, as well as San Mateo County in August. This week, the pest was found in Fresno.

Agencies in Southern California have been monitoring traps, but have yet to find any disease-carrying mosquitoes. 

"There is no evidence of aegypti in Los Angeles. B ut you can never say with 100% certainty," said Mark Daniel, director of operation s for the Greater Los Angeles County Vector Control Disctrict in the Los Angeles Times.

Yellow fever-carrying mosquitoes are also capable of harboring dengue fever; both diseases are viral that can be fatal if not treated appropriately. Yellow fever causes severe flu-like symptoms, at times jaundice as well. Dengue fever causes headaches, body pains, and a rash similar to what patients get when diagnosed with measles.

Cases of these diseasse have yet to be reported in California since the mosquitoes were found. The best way to cope with this alert is to prevent being bitten by these disease-carrying insects-- wearing insect repellents when being outdoors for a prolonged amount of time is advised. More importantly, preventing stagnant water from forming around the home can eradicate these pests from breeding. 

Reach Executive Producer Shoko Oda here.