Swarms of locusts have been seen in several districts of Cairo on Saturday, including Moqatam and New Cairo.
Some citizens burned tires to create a black fog to keep the locusts from settling in the city.
Swarms were earlier reported to have reached Egypt's Red Sea city of Zafarana, some 200 kilometres from Cairo, and then the Upper Egyptian city of Qena where locusts appeared in at least three major villages.
There has earlier been reports of a "plague of locusts," which some experts say could hit Egypt's Nile Delta.
Since January, swarms of the insects — originating from Sudan — have been spotted along the Red Sea coast in south-eastern Egypt, north-eastern Sudan, Eritrea and Saudi Arabia.
In 2004, Egypt witnessed one of the most serious locust infestations in recent history, when farmers in 15 out of the country's 27 governorates suffered extensive crop damage.
At the time, the Land Centre for Human Rights, a local NGO devoted to agriculture issues, reported that 38 percent of the nation's crops had been damaged as a direct result of the arrival of locusts.
According to the UN Food and Agriculture Organisation (FAO), one ton of locusts eat the same amount of food in a single day as around 2,500 people.