Apocrita

Definition

A suborder of Hymenoptera characterized by a narrow petiole ("wasp waist") separating the propodeum (first abdominal segment, fused to the thorax) from the remaining abdomen (metasoma). This constriction, which distinguishes Apocrita from the paraphyletic Symphyta (sawflies and horntails), evolved in association with the ancestral parasitoid lifestyle and provides enhanced maneuverability for the ovipositor. The group encompasses the vast majority of hymenopteran diversity, including ants, bees, and the majority of wasps, with larvae typically legless and either endoparasitic or reared in provisioned nests.

Etymology

From Greek apokritos, "separated, chosen," referring to the distinct narrow waist separating thorax and abdomen

Example

Braconid wasps, honey bees, and leafcutter ants are all members of Apocrita, sharing the constricted waist and derived larval development that characterize this suborder.

Related Terms

• Symphyta
• Hymenoptera
• petiole
• propodeum
• metasoma
• mesosoma
• Aculeata
• Parasitica
• ovipositor

Usage Notes

Technical descriptions of apocritan anatomy conventionally use mesosoma (thorax plus propodeum) and metasoma (remainder of abdomen) rather than "thorax" and "abdomen." The suborder is traditionally divided into Parasitica (largely parasitoid wasps with unconcealed ovipositors) and Aculeata (stinging wasps, ants, bees, with modified ovipositor/stinger), though Parasitica is paraphyletic with respect to Aculeata. The waist constriction is secondarily lost or reduced in some lineages (e.g., certain ants, some Cynipoidea).