''Fergusonina'', the sole genus in the family of Fergusoninidae, are gall-forming flies. There are about 40 species in the genus, all of them producing galls on ''

Eucalyptus ''Eucalyptus'' () is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of ''Eucalyptus'' are trees, often Mallee (habit), mallees, and a few are shrubs. Along with several other genera in the tribe Eucalyp ...

'', ''

Melaleuca ''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles, bottlebrushes or tea-trees (although the last name is also applied to species of '' Leptospermum''). They ...

'', ''

Corymbia ''Corymbia'', commonly known as bloodwoods, is a genus of about one hundred species of tree that, along with ''Eucalyptus'', '' Angophora'' and several smaller groups, are referred to as eucalypts. Until 1990, corymbias were included in the g ...

'', and ''

Metrosideros ''Metrosideros'' is a genus of approximately 60 trees, shrubs, and vines in the family Myrtaceae, mostly found in the Pacific region. Most of the tree forms are small, but some are exceptionally large, the New Zealand species in particular. The ...

'' species (all in the family

Myrtaceae Myrtaceae (), the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All ...

) in Australia and New Zealand. These flies are small and their larvae grow within galls formed on the leaf, shoot or flower buds. The galls themselves are induced by endosymbiotic nematodes in the genus '' Fergusobia'' (family

Neotylenchidae Neotylenchidae is a family of nematodes belonging to the order Tylenchida Tylenchida is an order (biology), order of nematodes. List of families * Superfamily Criconematoidea ** Family Criconematidae ** Family Tylenchulidae * Superfam ...

) which are obligate mutualists of the flies. Females carry the nematode in their haemocoel, and transport them to host plants while laying their eggs. Most of the fly species are specific to their tree hosts but a few use more than one species of host. The taxonomic placement of Fergusoninidae is disputed. While formerly in the superfamily

Opomyzoidea The Opomyzoidea are a Taxonomic rank, superfamily of fly, flies. Biology Opomyzoids show a range of lifestyles including mining plant leaves (many Agromyzidae), feeding in grass stems (Anthomyzidae and Opomyzidae), forming plant Gall, galls (' ...

, a 2020 study places it within superfamily

Nerioidea Nerioidea is a superfamily of Acalyptratae flies. Description As flies, Nerioidea undergo complete metamorphosis with the four life stages of egg, larva, pupa and adult. The adult stage has three body segments (head, thorax and abdomen), thr ...

based on morphology, while a 2021 study using

transcriptome The transcriptome is the set of all RNA transcripts, including coding and non-coding, in an individual or a population of cells. The term can also sometimes be used to refer to all RNAs, or just mRNA, depending on the particular experiment. The ...

data places it in a group along with

Agromyzidae The Agromyzidae are a family of flies, commonly referred to as the leaf-miner flies for the feeding habits of their larvae, most of which are leaf miners on various plants. It includes roughly 2,500 species, they are small, some with wing length ...

and other families

References

Further reading