Eutrichosoma

The genus is distinguished from other chalcidoid genera by its placement in the Planidial Larva Clade, characterized by first-instar larvae with specialized morphology for active host-seeking. A key to species of Eutrichosoma has been published. Adults are small chalcidoid wasps; specific diagnostic features for the genus require examination of morphological characters detailed in taxonomic revisions.

Associated with host plants of weevil hosts; field collections of E. mirabile were made from whitethorn acacia (Vachellia constricta).

Southeastern Arizona, USA (documented for E. mirabile from field collections in August 2016 and 2018). Broader geographic range for the genus is poorly documented.

Adult activity documented in August in southeastern Arizona.

• weevils (Coleoptera: Curculionidae) - parasitoidHost identity confirmed via 28S-D2 rDNA and COI-BC mtDNA sequences; subfamily, genus, and species unconfirmed
• whitethorn acacia (Vachellia constricta) - indirectHost plant of weevil hosts

First-instar larvae are planidia—highly mobile, sclerotized larvae adapted for active host-seeking. Larval morphology has been described for E. mirabile. Subsequent instars and pupal development occur within the host.

First-instar larvae actively seek out host weevils rather than being deposited directly on or in hosts. This planidial strategy represents an alternative to typical parasitoid oviposition behavior.

Parasitoid of weevil larvae (Curculionidae), with potential as a biological control agent.

Potential for biological control of weevil pests; however, specific applications have not been documented.

• other Pteromalidae (sensu lato)Eutrichosoma was historically placed in Pteromalidae but is now recognized in the distinct family Eutrichosomatidae; distinguished by planidial larval morphology and phylogenetic placement in the Planidial Larva Clade
• other planidial chalcidoids (e.g., Perilampidae, Eucharitidae, some Encyrtidae)Share the planidial larval strategy but differ in host associations, adult morphology, and phylogenetic placement within Chalcidoidea

• parasitoid
• planidia
• biological control
• weevil parasitoid
• Chalcidoidea
• Eutrichosomatidae
• Planidial Larva Clade

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Larval morphology and life history of Eutrichosoma mirabile Ashmead and description of a new species of Eutrichosoma (Hymenoptera, Chalcidoidea)
• Figure 3 from: Baker AJ, Heraty JM (2020) Larval morphology and life history of Eutrichosoma mirabile Ashmead and description of a new species of Eutrichosoma (Hymenoptera, Chalcidoidea). Journal of Hymenoptera Research 75: 67-85. https://doi.org/10.3897/jhr.75.47880
• Supplementary material 1 from: Baker AJ, Heraty JM (2020) Larval morphology and life history of Eutrichosoma mirabile Ashmead and description of a new species of Eutrichosoma (Hymenoptera, Chalcidoidea). Journal of Hymenoptera Research 75: 67-85. https://doi.org/10.3897/jhr.75.47880
• Figure 1 from: Baker AJ, Heraty JM (2020) Larval morphology and life history of Eutrichosoma mirabile Ashmead and description of a new species of Eutrichosoma (Hymenoptera, Chalcidoidea). Journal of Hymenoptera Research 75: 67-85. https://doi.org/10.3897/jhr.75.47880
• Figure 2 from: Baker AJ, Heraty JM (2020) Larval morphology and life history of Eutrichosoma mirabile Ashmead and description of a new species of Eutrichosoma (Hymenoptera, Chalcidoidea). Journal of Hymenoptera Research 75: 67-85. https://doi.org/10.3897/jhr.75.47880