Trichilogaster acaciaelongifoliae

{{Short description|Species of wasp}}

{{Italic title}}

{{Taxobox

| name = Trichilogaster acaciaelongifoliae

| image = Galls of Trichilogaster acaciaelongifoliae (Froggatt) 9798.jpg

| image_caption = Young galls of T. acaciaelongifoliae, still showing abortive flower rudiments.

| regnum = Animalia

| phylum = Arthropoda

| classis = Insecta

| ordo = Hymenoptera

| superfamilia = Chalcidoidea

| familia = Pteromalidae

| subfamilia = Ormocerinae

| genus = Trichilogaster

| species = T. acaciaelongifoliae

| binomial = Trichilogaster acaciaelongifoliae

| binomial_authority = (Froggatt, 1892)

}}

Trichilogaster acaciaelongifoliae is an Australian bud-galling wasp from the family Pteromalidae that parasitises, among others, Acacia longifolia (long-leaved wattle, or Sydney golden wattle), which has become an invasive pest in several countries. T. acaciaelongifoliae has been introduced into South Africa in 1985 and into Portugal in 2015 as a successful biological control agent of A. longifolia.Dennill, G.B., Donnelly, D., Steward, K. & Impson, F.A.C. 1999. Insect agents used for the biological control of Australian Acacia species and Paraserianthes lophantha (Willd.) Nielsen (Fabaceae) in South Africa. African Entomology Memoir 1: 45–54.{{Cite journal|last=Marchante|first=H.|last2=López-Núñez|first2=F. A.|last3=Freitas|first3=H.|last4=Hoffmann|first4=J. H.|last5=Impson|first5=F.|last6=Marchante|first6=E.|date=August 2017|title=First report of the establishment of the biocontrol agent Trichilogaster acaciaelongifoliae for control of invasive Acacia longifolia in Portugal|url=https://onlinelibrary.wiley.com/doi/10.1111/epp.12373|journal=EPPO Bulletin|language=en|volume=47|issue=2|pages=274–278|doi=10.1111/epp.12373|url-access=subscription}}