Plasmatocytes (Insect Germ Eaters)

Blood cells in bugs

Have you seen tiny fruit flies buzzing around a bowl of bananas? Scientists study them a lot, and that's how we know so much about their blood cells.

Insect blood is called hemolymph. It sloshes around inside the insect's body. It is usually clear, green or yellow, not red, because it doesn't carry oxygen. Insects get air through tiny tubes instead.

Plasmatocytes are round cells that float in this blood. In fruit flies, they are the most common kind of blood cell.

Clean-up crew

Plasmatocytes are like your macrophages, the big white blood cells that eat germs.

• They swallow germs that get into the insect.
• They clean up old and dead cells.
• They help send out signals that call the insect's body to fight an infection.

Plasmatocyte quiz