Mealybugs

Your photo is distant and we cannot make out the details of these insects clearly. If these insects have a cottony, fuzzy and sticky feel to them, it is likely your infestation is mealybugs. Mealybugs suck the nutrients out of the plant and will eventually kill it if left untreated. Consult your local garden center for confirmation of the problem and remedies. If they are mealybugs, you can hand remove them with a cotton swab dipped in alcohol and then rinsed off, but if the infestation is extensive, you may want to wash them off with a strong stream of water, followed by a spray with insecticidal soap or pyrethrin product. There are also chemical controls formulated with imidacloprid, but make sure it is formulated for citrus.