Neoneurini

Genus Guides

Neoneurini is a tribe of braconid wasps in the Euphorinae, historically treated as a separate subfamily but now placed within Euphorinae based on molecular data. The tribe contains three European —Elasmosoma, Kollasmosoma, and Neoneurus—comprising koinobiont endoparasitoids of ants. These possess highly specialized morphological adaptations for attacking ants, including a strongly curved, hook-shaped ovipositor directed forward, and modified legs with tarsal claws and enlarged for grasping metasomas. The tribe has a fossil record extending to Baltic amber.

Pronunciation

How to pronounce Neoneurini: /niːoʊnɪˈʊrɪnaɪ/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other Euphorinae by the combination of: anteriorly directed, strongly curved hook-shaped ovipositor; tarsal claws with enlarged on fore and middle legs; and specialized - . Separated from the related tribe Euphorini (which also parasitizes ants) by ovipositor curvature and leg structure. Distinguished from Ichneumonidae ant parasitoids (e.g., Hybrizontinae) by -level characters including wing venation and larval development site ( develop inside ants in Neoneurini, versus in ant larvae in Hybrizontinae).

Habitat

Associated with nests and zones of ant activity, particularly near nest entrances in open ground . Activity concentrated in warm, calm conditions. hover 1–3 cm above ground level to attack foraging ants. Not restricted to specific vegetation types, but dependent on presence of suitable ant colonies.

Distribution

Europe: documented from Spain, Slovakia, Norway, southern France, and the Netherlands. Palaearctic distribution. Fossil record from Baltic amber indicates wider historical distribution.

Host Associations

Formica rufa - of Elasmosoma
Formica pratensis - of Elasmosoma
Formica sanguinea - of Elasmosoma
Formica fusca - of Elasmosoma
Formica rufibarbis - of Elasmosoma
Formica subsericea - of Elasmosoma
Lasius niger - of Neoneurus
Cataglyphis bicolor - of Kollasmosoma
Cataglyphis ibericus - of Kollasmosoma sentum
Camponotus vagus - of Neoneurus
Polyergus - of Elasmosoma
Lasius schiefferdeckeri - Fossil from Baltic amber

Life Cycle

Koinobiont endoparasitoid of ants. are inserted through the into the metasoma, typically between abdominal segments. Larval development occurs within the living adult . Adults emerge from host nests; specific details of and larval instars not described. Development time and strategy unknown.

Behavior

Highly specialized rapid oviposition : females hover 1–3 cm above ground, approach ants from behind, grasp the metasoma with modified fore and middle legs, brace with hind legs on the apex of the metasoma, and insert the ovipositor through the . The entire process is extremely rapid, averaging approximately 0.7 seconds in Elasmosoma. Attacks are concentrated at the margin of the first gastral segment. are attracted to formic acid released during aggressive encounters. Success rate of attacks approximately 80%. Ants defend by turning toward the wasp, chasing, and striking with .

Ecological Role

of ants, potentially significant mortality factor for in the Formica and related . May regulate ant colony dynamics, particularly in formicine ants. Position in as specialized of social insects.

Human Relevance

Subject of behavioral research due to remarkable adaptations for attacking defended . No direct economic importance; not used in . Scientific interest in understanding evolutionary arms races between and social insect defenses.

Similar Taxa

EuphoriniAlso Euphorinae , but differ in ovipositor structure (less curved, not anteriorly directed) and leg modifications; molecular data supports separate tribal status
Hybrizontinae (Ichneumonidae)Also with similar range, but belong to different ; develop in ant larvae rather than ants, and oviposition involves hovering over ant trails rather than ground-level attack
EucharitidaeThird major group of , but attack ant rather than ; females are much larger and use different -finding strategies

More Details

Taxonomic history

Neoneurini was historically treated as a separate (Neoneurinae) within Braconidae. Molecular phylogenetic data has demonstrated that it is nested within Euphorinae, leading to its current tribal status.

Fossil record

The tribe is represented in Baltic amber by the extinct Elasmosomites, including E. primordialis (1933) and E. arkadyleleji sp. nov., indicating ancient associations with ants dating to at least the Eocene.

Oviposition mechanics

High-speed video (300 fps) revealed that the curved, anteriorly directed ovipositor is essential for the rapid insertion through the while the maintains a stable grasp on the metasoma. This represents a key innovation for exploiting ant .