Chrysidinae

Distinguished from other chrysidid subfamilies by the combination of strongly convex terga with concealed laterotergites and the ability to roll into a compact ball. The three visible metasomal segments in most adults (vs. four in parnopine males) separates them from some related groups. The brilliant metallic coloration and heavily sculptured surface are characteristic but not unique; behavioral confirmation of the rolling defensive posture provides stronger identification. The "scurry and fly" search pattern—landing, running in short hesitant spurts with quivering antennae, then abruptly taking off—is highly distinctive even at distance.

Highly sculptured body with brilliant metallic coloration spanning the entire spectrum, predominantly blues and greens. Terga strongly convex with laterotergite not easily visible ventrally around sterna. Sterna flat or concave, not visible from lateral view. Females and males possess three visible metasomal segments (parnopine males have four). Metasoma capable of folding up against head and thorax to cover legs and lower head. Heavily sculptured integument provides physical protection.

Most diverse in desert regions worldwide, associated with high diversity of solitary bee and wasp hosts. Active in dry, warm, open areas. Strongly linked to habitats supporting their hosts: ground-nesting and cavity-nesting solitary Hymenoptera in exposed, sunlit environments.

Worldwide distribution with five tribes showing geographic variation: Chrysidini and Elampini abundant and widespread; Allocoeliini restricted to South Africa; Kimseyini containing single genus and species in Uzbekistan.

Adult activity concentrated between May and August in temperate regions, corresponding to warm, dry conditions and host nesting activity.

Adults consume flower nectar. Larvae are obligate brood parasites, consuming host eggs or larvae and their provisions.

• Crabronidae - brood parasitehosts include crabronid wasps
• Apoidea - brood parasitehosts include solitary bees
• Eumeninae - brood parasitehosts include eumenine vespids

Eggs laid in host nests using tube-like ovipositor. Larvae consume host egg or young larva, then feed on stored provisions. Developmental details of pupation and overwintering stages not specified in sources.

Exhibits distinctive "scurry and fly" host-searching pattern: lands on soil or wood, runs in quick hesitant spurts with vigorously quivering antennae, then abruptly takes short flight before repeating. Defensive rolling behavior: folds metasoma against head and thorax to cover legs and lower head, presenting sculptured exoskeleton to threats. Females cannot sting; defense is entirely passive.

Brood parasites of solitary Hymenoptera, regulating populations of bees and wasps. Contribute to ecosystem dynamics in arid regions where host diversity is highest.

Subject of online identification guides for North American fauna. Metallic appearance attracts attention from naturalists and photographers. No documented economic impact; neither beneficial nor harmful to human interests.

• CleptinaeOther chrysidid subfamily; distinguished by different abdominal structure and inability to roll into complete ball
• LoboscelidiinaeOther chrysidid subfamily; males have highly modified antennae not seen in Chrysidinae

• parasitoid
• metallic
• desert fauna
• kleptoparasite
• Hymenoptera
• solitary wasp parasite

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life