Case of mistaken identity: resolving the taxonomy between Trioza eugeniae Froggatt and T. adventicia Tuthill (Psylloidea: Triozidae).

The 'Eugenia psyllid' or 'Lilly pilly psyllid', widely recognized in Australia and in the USA as Trioza eugeniae Froggatt (Hemiptera: Triozidae), is not T. eugeniae, but rather T. adventicia Tuthill. In this study we assessed morphological comparisons of materials from throughout the native and introduced ranges and re-examined original descriptions of both taxa, together with Froggatt's type specimens of T. eugeniae. Furthermore, through DNA barcoding analyses, we confirmed the validity of both T. adventicia and T. eugeniae as separate species. We re-described both species to include additional characters not previously included and designated a lectotype for T. eugeniae. T. eugeniae has smaller fore wings that are slightly more elongate. These lack infuscation around veins R and R1, vein Rs is relatively longer, meeting the costa closer to the wing apex; with certain veins bearing long, fine divergent setae, a character not previously described. It has consistently three inner and one outer metatibial spurs. The male parameres appear narrowly pyriform with a weak dorsolateral lobe and weakly sclerotized apices. T. adventicia has larger fore wings that are slightly more ovate with dark infuscation around veins R and R1; vein Rs is relatively shorter, meeting the costa further from the wing apex, with veins lacking long, fine divergent setae. The usual configuration of two inner and one outer metatibial spurs, previously used to separate the two species, appears inconsistent. The male parameres appear a little more broadly pyriform with slightly more sclerotized apices. T. eugeniae refers to a distinct species which has a restricted distribution only in its native range in southern subcoastal New South Wales, Australia. T. adventicia refers to a separate species, with a natural distribution in eastern subcoastal Australia, but has been introduced widely in southern Australia, to New Zealand and the USA. This study elucidates a long history of misidentification of T. eugeniae in the nursery industry and in almost 30 years of literature on its biological control in the USA. Regardless, the biological control program, unknowingly, targeted the correct species of psyllid, T. adventicia, in its foreign exploration and importation of the appropriate parasitoid as a biocontrol agent in the USA. Despite being firmly entrenched in both the nursery trade and scientific literature, the name T. eugeniae is misapplied. While the acceptance of the valid name, T. adventicia, might be regarded as both problematic and protracted, this is the correct taxonomical attribution.

Unravelling mummies: cryptic diversity, host specificity, trophic and coevolutionary interactions in psyllid - parasitoid food webs.

BACKGROUND: Parasitoids are hyperdiverse and can contain morphologically and functionally cryptic species, making them challenging to study. Parasitoid speciation can arise from specialisation on niches or diverging hosts. However, which process dominates is unclear because cospeciation across multiple parasitoid and host species has rarely been tested. Host specificity and trophic interactions of the parasitoids of psyllids (Hemiptera) remain mostly unknown, but these factors are fundamentally important for understanding of species diversity, and have important applied implications for biological control. RESULTS: We sampled diverse parasitoid communities from eight Eucalyptus-feeding psyllid species in the genera Cardiaspina and Spondyliaspis, and characterised their phylogenetic and trophic relationships using a novel approach that forensically linked emerging parasitoids with the presence of their DNA in post-emergence insect mummies. We also tested whether parasitoids have cospeciated with their psyllid hosts. The parasitoid communities included three Psyllaephagus morphospecies (two primary and, unexpectedly, one heteronomous hyperparasitoid that uses different host species for male and female development), and the hyperparasitoid, Coccidoctonus psyllae. However, the number of genetically delimited Psyllaephagus species was three times higher than the number of recognisable morphospecies, while the hyperparasitoid formed a single generalist species. In spite of this, cophylogenetic analysis revealed unprecedented codivergence of this hyperparasitoid with its primary parasitoid host, suggesting that this single hyperparasitoid species is possibly diverging into host-specific species. Overall, parasitoid and hyperparasitoid diversification was characterised by functional conservation of morphospecies, high host specificity and some host switching between sympatric psyllid hosts. CONCLUSIONS: We conclude that host specialisation, host codivergence and host switching are important factors driving the species diversity of endoparasitoid communities of specialist host herbivores. Specialisation in parasitoids can also result in heteronomous life histories that may be more common than appreciated. A host generalist strategy may be rare in endoparasitoids of specialist herbivores despite the high conservation of morphology and trophic roles, and endoparasitoid species richness is likely to be much higher than previously estimated. This also implies that the success of biological control requires detailed investigation to enable accurate identification of parasitoid-host interactions before candidate parasitoid species are selected as biological control agents for target pests.

Codivergence of the primary bacterial endosymbiont of psyllids versus host switches and replacement of their secondary bacterial endosymbionts.

Coevolution between insects and bacterial endosymbionts contributes to the success of many insect lineages. For the first time, we tested for phylogenetic codivergence across multiple taxonomic scales, from within genera to superfamily between 36 psyllid species of seven recognised families (Hemiptera: Psylloidea), their exclusive primary endosymbiont Carsonella and more diverse secondary endosymbionts (S-endosymbionts). Within Aphalaridae, we found that Carsonella and S-endosymbionts were fixed in one Glycaspis and 12 Cardiaspina populations. The dominant S-endosymbiont was Arsenophonus, while Sodalis was detected in one Cardiaspina species. We demonstrated vertical transmission for Carsonella and Arsenophonus in three Cardiaspina species. We found strong support for strict cospeciation and validated the informative content of Carsonella as extended host genome for inference of psyllid relationships. However, S-endosymbiont and host phylogenies were incongruent, and displayed signs of host switching and endosymbiont replacement. The high incidence of Arsenophonus in psyllids and other plant sap-feeding Hemiptera may be due to repeated host switching within this group. In two psyllid lineages, Arsenophonus and Sodalis genes exhibited accelerated evolutionary rates and AT-biases characteristic of long-term host associations. Together with strict vertical transmission and 100% prevalence within host populations, our results suggest an obligate, and not facultative, symbiosis between psyllids and some S-endosymbionts.

Visual acuity trade-offs and microhabitat-driven adaptation of searching behaviour in psyllids (Hemiptera: Psylloidea: Aphalaridae).

Insects have evolved morphological and physiological adaptations in response to selection pressures inherent to their ecology. Consequently, visual performance and acuity often significantly vary between different insect species. Whilst psychophysics has allowed for the accurate determination of visual acuity for some Lepidoptera and Hymenoptera, very little is known about other insect taxa that cannot be trained to positively respond to a given stimulus. In this study, we demonstrate that prior knowledge of insect colour preferences can be used to facilitate acuity testing. We focused on four psyllid species (Hemiptera: Psylloidea: Aphalaridae), namely Ctenarytaina eucalypti, Ctenarytaina bipartita, Anoeconeossa bundoorensis and Glycaspis brimblecombei, that differ in their colour preferences and utilization of different host-plant modules (e.g. apical buds, stems, leaf lamellae) and tested their visual acuity in a modified Y-maze adapted to suit psyllid searching behaviour. Our study revealed that psyllids have visual acuity ranging from 6.3 to 8.7 deg. Morphological measurements for different species showed a close match between inter-ommatidial angles and behaviourally determined visual angles (between 5.5 and 6.6 deg) suggesting detection of colour stimuli at the single ommatidium level. Whilst our data support isometric scaling of psyllids' eyes for C. eucalypti, C. bipartita and G. brimblecombei, a morphological trade-off between light sensitivity and spatial resolution was found in A. bundoorensis. Overall, species whose microhabitat preferences require more movement between modules appear to possess superior visual acuity. The psyllid searching behaviours that we describe with the help of tracking software depict species-specific strategies that presumably evolved to optimize searching for food and oviposition sites.

Two new species of Selitrichodes (Hymenoptera: Eulophidae: Tetrastichinae) inducing galls on Casuarina (Casuarinaceae).

Two new species of gall-inducing wasps, Selitrichodes casuarinae Fisher & La Salle sp. n. and Selitrichodes utilis Fisher & La Salle sp. n., are described from Micronesia (Guam, Rota and Palau Islands) and Australia respectively. These species induce galls on Casuarina and can cause extensive damage to the trees. Their status as pest or beneficial species is discussed.

Potential economic pests of solanaceous crops: a new species of Solanum-feeding psyllid from Australia and first record from New Zealand of Acizzia solanicola (Hemiptera: Psyllidae).

Acizzia credoensis sp. n. is described from a single population on the native plant, Solanum lasiophyllum, from semi-arid Western Australia. The host range of Acizzia solanicola Kent & Taylor, initially recorded as damaging eggplant, S. melongena, in commercial crops and gardens and on wild tobacco bush, S. mauritianum in eastern Australia, is expanded to include the following Solanaceae: rock nightshade, S. petrophilum, cape gooseberry, Physalis peruviana, and an undetermined species of angel's trumpet Brugmansia and Datura. New Zealand specimens of A. solanicola collected in early 2012 from S. mauritianum are the first record for this species from outside Australia, and possibly represent a very recent incursion. The potential for the solanaceous-inhabiting Psyllidae to vector Candidatus Liberibacter solanacearum, an economically important plant pathogen, on native Australian Solanaceae is discussed. The occurrence of A. credoensis and A. solanicola on native Australian Solanum supports the Australian origin for the solanaceous-inhabiting Acizzia psyllids.

Anoeconeossa bundoorensis sp. n., a new psyllid (Hemiptera: Psylloidea) from Eucalyptus camaldulensis (Myrtaceae) from Southeast Australia.

Anoeconeossa bundoorensis sp. n. is described from Eucalyptus camaldulensis (Myrtaceae) from southern Victoria in Southeast Australia. It is placed in the A. communis Taylor species-group as the paramere lacks combs of black rods. It differs from other members of the species-group, A. communis and A. bullata Taylor as it lacks an anterobasal expansion on the paramere and from A. unicornuta Taylor as the inner horn-shaped process of the paramere is reduced to a short spine and the apical expansion is more elongate, with a corresponding greater length of equidistant setae. Taxonomically relevant morphological details are illustrated and the species is diagnosed from other eucalypt inhabiting congeners. In-formation on the biology is presented.

Ctenarytaina bipartita sp. n. (Hemiptera, Psylloidea), a new eucalypt psyllid from Southeast Australia.

Ctenarytaina bipartita sp.n., associated with Eucalyptus kitsoniana and E. viminalis, is described from the Australian Capital Territory, New South Wales, Tasmania and Victoria. It differs from other described Ctenarytaina species in the paramere which bears a small posterior lobe. Taxonomically relevant morphological details are illustrated and the species is diagnosed from other eucalypt inhabiting congeners. Information on the biology is also given. C. bipartita has the potential to become an exported pest species to countries with significant eucalypt plantations.

Nematodes from galls on Myrtaceae. IV. Fergusobia from flat leaf galls on Eucalyptus and Corymbia, with descriptions of two new species.

Two new species of Fergusobia are described. Both were collected from flat leaf galls from South Australia, one on Eucalyptus microcarpa and the other on E. porosa. Fergusobia microcarpae n. sp. Davies is characterised by the combination of a C-shaped parthenogenetic female with a short, broadly rounded conoid tail, an arcuate to open C-shaped infective female with an hemispherical tail tip, and arcuate to J-shaped males with angular spicules and short peloderan bursa. Fergusobia porosae n. sp. Davies is similar in having an arcuate to C-shaped parthenogenetic female with a small conoid tail, an almost straight to arcuate infective female with an hemispherical tail tip, and males that are almost straight to barely J-shaped with angular spicules and short peloderan bursa. They differ in that the bodies of parthenogenetic and infective females of F. microcarpae n. sp. are more curved than in F. porosae n. sp. Other known similar forms of Fergusobia/Fergusonina galls are outlined and the larval shield morphologies of their associated mutualistic Fergusonina fly species are discussed where known. An inventory of all known Fergusobia/Fergusonina associations from flat leaf galls from Corymbia spp. and Eucalyptus spp. is presented. Relationships of Fergusobia nematodes were inferred from analysis of sequences of 28S rDNA D2/D3 domains and a portion of mitochondrial DNA cytochrome oxidase subunit I (mtCOI). Nematodes from flat leaf galls appeared in two clades. 

Nematodes from galls on Myrtaceae. V. Fergusobia from large multilocular shoot bud galls from Angophora and Eucalyptus in Australia, with descriptions of six new species.

Six new species of Fergusobia, from large multilocular shoot bud galls on two species of Angophora and four species of Eucalyptus from both subgenera Eucalyptus and Symphyomyrtus, are described. Fergusobia cosmophyllae Davies n. sp. is characterized by the combination of a C-shaped parthenogenetic female with a short arcuate conoid tail, a broad (small a ratio) arcuate infective female with an hemispherical tail tip, and an arcuate to J-shaped male with broad, angular spicules and short bursa.  Fergusobia delegatensae Davies n. sp. has an open C-shaped parthenogenetic female with a broadly conoid tail, an infective female of variable shape with an hemispherical tail tip, and a male of open C-shape with a crenate bursa that arises 40-70% along the length of the body from the tail tip and terminates just anterior to the cloaca. Fergusobia diversifoliae Davies n. sp. has a C-shaped parthenogenetic female with a conoid tail, an arcuate infective female with a hemispherical tail tip, and an arcuate, C- or J-shaped male with angular spicule and a long peloderan bursa. Fergusobia floribundae Davies n. sp. has a C-shaped parthenogenetic female with a narrow, arcuate, conoid tail, an arcuate infective female with a hemispherical tail tip, and an arcuate or J-shaped male with an angular spicule and a short to mid-body length peloderan bursa. Fergusobia minimus Lisnawita n. sp. has a C-shaped parthenogenetic female with a conoid tail, an arcuate to open C-shaped infective female with a hemispherical tail tip, and an arcuate to open C-shaped male with an angular spicule and a peloderan bursa arising at about 10-30% of body length. Fergusobia pimpamensis Davies n. sp. has an open C to C-shaped parthenogenetic female with a narrow conoid tail, an arcuate to open C-shaped infective female with a hemispherical tail tip, and an arcuate to C-shaped male with an arcuate spicule and a long, crenate, peloderan bursa. An inventory of all known Fergusobia/Fergusonina associations from terminal shoot bud galls is presented. The larval shield morphology of the associated mutualistic Fergusonina species is discussed where known. Analyses of DNA sequences of D2/D3 and COI suggested that the six new species are distributed between three clades of Fergusobia.

A new Australian species of invasive psyllid, Acizzia convector Burckhardt & Taylor, sp. nov. (Psylloidea: Psyllidae) associated with Acacia auriculiformis and A. mangium (Fabaceae).

Acizzia convector Burckhardt & Taylor, sp. nov., a psyllid originating from Australia, is described from material from Australia (NT), South and Southeast Asia (Brunei, Cambodia, India, Laos, Malaysia [Sabah], Singapore and Thailand) and North America (USA [Florida from six counties]). The new species is diagnosed and illustrated, and a key is provided to identify the adults of Acizzia species adventive in the New World. The new species develops on Acacia auriculiformis and A. mangium (Fabaceae), two mimosoids planted and widely naturalised throughout the tropics. While the presence of A. convector sp. nov. in Florida is probably recent (earliest record from October 2014), it occurs in Southeast Asia at least since the 1980s. The wide distribution of the host plants in tropical Africa and South America would allow the psyllids also to occur there.

Insect phylogeny structures the bacterial communities in the microbiome of psyllids (Hemiptera: Psylloidea) in Aotearoa New Zealand.

The bacterial microbiome of psyllids has been studied for decades, with a strong focus on the primary and secondary endosymbionts capable of providing essential amino acids for the insects' diet and therefore playing a key role in the insects' ability to radiate on novel plant hosts. Here, we combine metabarcoding analysis of the bacterial communities hosted by psyllids with a multi-gene phylogenetic analysis of the insect hosts to determine what factors influence the bacterial diversity of the psyllids' microbiomes, especially in the context of the dispersal and evolutionary radiation of these insects in Aotearoa New Zealand. Using multi-gene phylogenetics with COI, 18S and EF-1α sequences from 102 psyllid species, we confirmed for the first time monophyly for all the six genera of native/endemic Aotearoa New Zealand psyllids, with indications that they derive from at least six dispersal events to the country. This also revealed that, after its ancestral arrival, the genus Powellia has radiated onto a larger and more diverse range of plants than either Psylla or Ctenarytaina, which is uncommon amongst monophyletic psyllids globally. DNA metabarcoding of the bacterial 16S gene here represents the largest dataset analysed to date from psyllids, including 246 individuals from 73 species. This provides novel evidence that bacterial diversity across psyllid species is strongly associated with psyllid phylogenetic structure, and to a lesser degree to their host plant association and geographic distribution. Furthermore, while the strongest co-phylogenetic signals were derived from the primary and secondary symbionts, a signal of phylosymbiosis was still retained among the remaining taxa of the bacterial microbiome, suggesting potential vertical transmission of bacterial lineages previously unknown to have symbiotic roles.

A national-scale dataset for threats impacting Australia's imperiled flora and fauna.

Australia is in the midst of an extinction crisis, having already lost 10% of terrestrial mammal fauna since European settlement and with hundreds of other species at high risk of extinction. The decline of the nation's biota is a result of an array of threatening processes; however, a comprehensive taxon-specific understanding of threats and their relative impacts remains undocumented nationally. Using expert consultation, we compile the first complete, validated, and consistent taxon-specific threat and impact dataset for all nationally listed threatened taxa in Australia. We confined our analysis to 1,795 terrestrial and aquatic taxa listed as threatened (Vulnerable, Endangered, or Critically Endangered) under Australian Commonwealth law. We engaged taxonomic experts to generate taxon-specific threat and threat impact information to consistently apply the IUCN Threat Classification Scheme and Threat Impact Scoring System, as well as eight broad-level threats and 51 subcategory threats, for all 1,795 threatened terrestrial and aquatic threatened taxa. This compilation produced 4,877 unique taxon-threat-impact combinations with the most frequently listed threats being Habitat loss, fragmentation, and degradation (n = 1,210 taxa), and Invasive species and disease (n = 966 taxa). Yet when only high-impact threats or medium-impact threats are considered, Invasive species and disease become the most prevalent threats. This dataset provides critical information for conservation action planning, national legislation and policy, and prioritizing investments in threatened species management and recovery.

Illuminating Insights into the Biodiversity of the Australian Psyllids (Hemiptera: Psylloidea) Collected Using Light Trapping.

The superfamily Psylloidea includes numerous species which play a key role in Australian ecology and biodiversity, as well as pests and biological control agents, and sometimes threatened species of conservation concern. Different psyllid sampling and collection techniques are usually performed depending on the nature and aim of the study: from the beating and sweeping of psyllid host plants for conservation and biodiversity assessment, to suction and sticky traps in agriculture. Due to a general lack of information on its efficacy for psyllids, however, light trapping has not usually been employed. Here we present the results obtained trapping psyllids using different light sources and we discuss the strengths and weaknesses of this technique to assess psyllid biodiversity. In particular, we highlight the strength of using this methodology paired with DNA barcoding, to cast some light on psyllid biodiversity. The results obtained here suggest that the psyllid fauna of Australia is heavily understudied and the number of undescribed species might be many times higher than previously expected. Additionally, we report, for the first time, the species Trioza adventicia Tuthill 1952, and Cryptoneossa triangula Taylor 1990 in the state of Queensland.

Molecular evidence of hybridization in Florida's sheoak (Casuarina spp.) invasion.

The presence of hybrids in plant invasions can indicate a potential for rapid adaptation and an added level of complexity in management of the invasion. Three Casuarina tree species, Casuarina glauca, Casuarina cunninghamiana and Casuarina equisetifolia, native to Australia, are naturalized in Florida, USA. Many Florida Casuarina trees are considered unidentifiable, presumably due to interspecific hybridization. We collected tissue from over 500 trees from Australia and Florida and genotyped these using amplified fragment length polymorphisms. Our goal was to determine the exact identity of the Florida species, including any putative hybrid combinations. In Australia, we found high assignment values to the three parental species, and no evidence of hybridization. In Florida, we found many trees with strong assignment to any one of the three species, as well as 49 trees with assignment values intermediate to C. glauca and C. equisetifolia, suggesting hybridization between these species. One population of 10 trees had assignment values intermediate to C. cunninghamiana and C. glauca, suggesting additional hybridization. For 69 of these putative hybrid and parental types, we sequenced a low-copy intron of nuclear G3pdh, and these sequences indicated that some Florida trees contain heterozygotic combinations of C. glauca and C. equisetifolia haplotypes. The presence of novel hybrids in the Florida invasion may enhance evolution of invasive traits in these species. Novel Casuarina hybrids in Florida have no coevolutionary history with any insects or diseases, which may be problematic for biological control efforts.

New species of gall fly (Diptera: Fergusoninidae) from Eucalyptus camaldulensis (Myrtaceae) in southern Australia and its associated parasitoids and inquilines.

A new species of gall fly, Fergusonina nodulosa sp. nov. (Diptera: Fergusoninidae) is described from Eucalyptus camaldulensis Dehnh. (Myrtaceae) in southern Australia. The adult fly is yellow with dark brown to black markings, the male postgonites have one large distal tooth and an ovoid subapical lobe with two lateral setae, the female postabdomen is short and sparsely setose, and the wing has a posterior cross vein. The larva possesses a dorsal shield comprising rows of raised spicules on thoracic segments 1-3 and abdominal segments 1-7, and the puparium is heavily sclerotised dark brown, barrel-shaped, bearing the dorsal shield. Fergusonina nodulosa sp. nov. forms nodular 'stem' galls initiating from the axial shoot buds. The galls are 2-8 mm in diameter with an average volume of 123 (range 25-480) mm3. Thirteen species of Hymenoptera, comprising primary parasitoids and hyperparasitoids of the gall fly and associated lepidopteran inquilines, and three species of Lepidoptera inquilines were reared from galls of this new species. Fergusonina nodulosa sp. nov. is associated with the obligate mutualist nematode, Fergusobia camaldulensae Davies.

Nematodes from galls on Myrtaceae. XI. Descriptions of five new species of Fergusobia from Australia.

Five new species of Fergusobia are described. Fergusobia janetae Davies n. sp. is characterized by the combination of an arcuate to straight, spindle-shaped parthenogenetic female with a relatively small oesophageal gland, an extensile uterus and a conoid tail, an arcuate infective female with a bluntly rounded tail tip, and a C-shaped male with an arcuate to angular spicule and bursa arising at more than 90% of body length. Fergusobia robustae Davies n. sp. is characterized by the combination of a small, C-shaped parthenogenetic female with a short cylindroid tail with a broadly rounded tip; an arcuate to C-shaped, relatively broad, infective female with a tail tip that is almost hemispherical; and an arcuate male with a strong angular spicule and a bursa arising at 30-40% of body length. Fergusobia pruinosae Davies n. sp. is characterized by the combination of a medium sized, open C-shaped, parthenogenetic female in which the cuticle does not swell upon fixation, with a strongly sclerotised stylet, with a more or less narrowly conoid tail with a bluntly or broadly rounded tip; infective female that is arcuate to J-shaped with a notched tail tip; and open C-shaped males with stout, angular spicules and bursa arising near the secretory/excretory pore. Fergusobia pauciflorae Davies n. sp. is characterized by the combination of a medium sized, arcuate, parthenogenetic female with a small stylet, and a conoid tail with a bluntly rounded tip; a small, open C to J-shaped infective female with a broadly rounded to almost hemispherical tail tip; and straight to arcuate males with stout, angular spicules and bursa at ~70% of body length anterior to the cloaca. Fergusobia obliquae Davies n. sp. has a relatively broad, arcuate, parthenogenetic female having a small but strongly sclerotised stylet, and a short conoid tail with a bluntly rounded tip; an arcuate, infective female with an almost hemispherical tail tip; and C-shaped males with arcuate to angular (not heavily sclerotised) spicules and bursa arising 50-80% of body length anterior to tail. Sequencing of the 18S and 28S rDNA domains for F. janetae n. sp. and of mitochondrial DNA cytochrome oxidase subunit I (mtCOI) for F. pauciflorae n. sp. confirm that they are distinct species.

Myotrioza myopori Taylor, a designation of the type species for the genus Myotrioza gen. nov. (Psylloidea: Triozidae).

Taylor et al. (2016) described twenty new species in one new genus of Australian jumping plant-lice from the plant family Scrophulariaceae but did not nominate a type species, a requirement under the International Code of Zoological Nomenclature under Article 13.3 to make the genus name available (ICZN 1999).

A new genus and twenty new species of Australian jumping plant-lice (Psylloidea: Triozidae) from Eremophila and Myoporum (Scrophulariaceae: Myoporeae).

The Triozidae is a diverse, cosmopolitan family of jumping plant-lice (Hemiptera: Psylloidea) from an exceptionally diverse range of plant families, but with few described Australian species. As a direct outcome of the Australian Biological Resources Study Bush Blitz species discovery program, many new Psylloidea from novel host plants in remote localities have been revealed. In this study a new genus Myotrioza Taylor gen. nov. and 20 new species are described from southern and central Australia which also establishes the first host plant records from Eremophila and Myoporum (Scrophulariaceae: Myoporeae). New species, delineated using a combination of morphological and mitochondrial COI sequence data, are: Myotrioza clementsiana sp. nov., M. darwinensis sp. nov., M. desertorum sp. nov., M. eremi sp. nov., M. eremophili sp. nov., M. flindersiana sp.nov., M. gawlerensis sp. nov., M. insularis sp. nov., M. interioris sp. nov., M. interstantis sp. nov., M. longifoliae sp. nov., M. markmitchelli sp. nov., M. myopori sp. nov., M. oppositifoliae sp. nov., M. pantonii sp. nov., M. platycarpi sp. nov., M. remota sp. nov., M. scopariae sp. nov., M. serrulatae sp. nov., and M. telowiensis sp. nov. Genetic divergence data, host associations, biogeographic data, diagnoses and a key to species are presented. Myotrioza appears to be particularly diverse in ephemeral southern Australia, especially in inland Western Australia and South Australia, matching regions of high diversity of the host genera; some species are likely to be short range endemics.