Characteristics
- Distinct abdominal waist between thorax (mesosoma) and abdomen (metasoma)
- Well-developed, often elbowed antennae
- Females possess a modified ovipositor (stinger, drill, or egg-laying organ)
- Membranous wings with more or less complete venation
- Complete metamorphosis (egg → larva → pupa → adult)
Notable Families
- Apidae – Pollinating bees (honeybee, bumblebees…)
- Vespidae – Social or solitary predatory wasps
- Formicidae – Ants, fully social
- Ichneumonidae, Braconidae – Parasitoid wasps
- Chalcidoidea (superfamily) – Tiny parasitoids, sometimes hyperparasites
- Sphecidae, Crabronidae, Scoliidae, Pompilidae – Predatory or parasitoid wasps
Habitat
Apocrita are found in:
- Forests, meadows, dunes, gardens, hedgerows, agricultural zones
- Bare soil, deadwood, plant cavities, subterranean or aerial nests
- Flowers, foliage, trunks, litter, and human-influenced habitats
Biology
Various lifestyles:
- Solitary: digger wasps, ground-nesting bees…
- Social: honeybees, ants, social wasps
- Parasitoid: ichneumons, braconids, chalcids…
- Predatory: sphecoids, pompilids…
- Phytophagous: rare, mostly in primitive forms
Feeding habits:
- Adults: nectar, pollen, honeydew, prey, secretions
- Larvae: nectar and pollen (bees), paralyzed insects, parasitized hosts…
Distinctive Features
- Great morphological and behavioral diversity
- Presence of social castes in several families
- Ecological importance: pollination, pest regulation, soil engineering
- Sometimes mistaken for sawflies (Symphyta), from which they differ by their wasp waist
Apocrita
They are characterized by a distinct constriction at the level of the abdomen: the first abdominal segment, fused with the thorax, is called the propodeum. The second abdominal segment, called the petiole, is very narrow, sometimes only at the base but sometimes along its entire length. The enlarged part of the abdomen is called the gaster.