Adult Asian Citrus Psyllids are about the size of an aphid.


Photo credit: California Dept. of Food and Agriculture
From the California Citrus Research Board: “Adult Asian Citrus Psyllids are small (3-4 mm or 1/8-1/6 inch), brownish insects that are similar in size to an aphid. They feed with their heads down, almost touching the surface of the leaf. Because of the shape of their heads, their bodies are lifted to approximately a 45-degree angle… The psyllids develop from an egg through five nymphal stages that look similar, but increase in size after each molt. Due to the small size – even of adult psyllids – inspection is done more easily with a magnifying glass or hand lens.”