The tiger mosquito and the yellow fever mosquito are both small, but the tiger mosquito is black and the yellow fever mosquito is dark brown. This difference in color is difficult for non-experts to perceive. A better way to tell the difference is to check the lines on the thorax: the yellow fever mosquito has white lines on the thorax in the shape of a lyre, but the tiger mosqutio has only one white line.
It is quite normal to be mistaken or unsure when identifying the mosquitos. A team of experts will validate the information contained in the photo and will classify the photo adding any additional comments if necessary. Also, other users can also provide their opinions via the collective validation platform.