Aphids

Aphids, like the ones on this plant, can be major agricultural pests.  They have a long, needle-like mouthpart called a rostrum that they use to jab into the leaves and drain the plant sap.  Even though aphids are small, they're pretty easy to identify - just look for the rounded, squishy bodies and two cornicles coming off the end of the abdomen (cornicles look a bit like short little tubes).  These aphids were feeding in a community garden in Chimaltenango, Guatemala. If you want to learn how aphids warn each other when predators are near check out our post: Message in a Cornicle.