This suborder includes parasitoid, social, and solitary wasps, bees, and ants. The insects of this suborder can be recognized by the deep constriction of the abdomen between the first abdominal segment and the second. The first segment of the abdomen is incorporated into the thorax to form the propodeum, which always possesses a pair of spiracles.
The ovipositor can be modified to serve as a special function. In the parasitic Apocrita, the ovipositor is functioning to lay eggs into or onto arthropodean prey, into plant tissue, etc. In non-social Aculeata, it is modified for stinging to paralyse, to kill or to defend. In social bees and ants, it may be specialized to dispense repellants, to trail alarm substances or pheromones, or it may be lost.
The larvae are apodous and nearly always possess a reduced head capsule, without appendages and with into papillae modified antennae. The main occupation of the larva is eating within or upon the body of a host arthropod or its eggs, in a plant gall, fruit, or seed or in a nest constructed by the adult(s). The forms and lifestyle of the larvae are often greatly modified to the microhabitats that they occupy.
The adults feed on nectar or honeydew of Homoptera. Females may use body fluid of arthropod prey. The Apocrita are distributed worldwide, with the exception of Antarctica and other environments with extreme conditions.
The suborder Apocrita is customarily separated into two main divisions: the Aculeata, or stinging forms; and the Parasitica, which are parasites of other insects. The distinctions between the two groups are difficult to draw, being neither practical nor biologically consistent. Although some 125.000 species have already been described, a very large number of others remain undescribed.