Psyllid Species Research Articles

Microbiome analyses of 12 psyllid species of the family Psyllidae identified various bacteria including Fukatsuia and Serratia symbiotica, known as secondary symbionts of aphids

BackgroundPsyllids (Hemiptera: Psylloidea) comprise a group of plant sap-sucking insects that includes important agricultural pests. They have close associations not only with plant pathogens, but also with various microbes, including obligate mutualists and facultative symbionts. Recent studies are revealing that interactions among such bacterial populations are important for psyllid biology and host plant pathology. In the present study, to obtain further insight into the ecological and evolutionary behaviors of bacteria in Psylloidea, we analyzed the microbiomes of 12 psyllid species belonging to the family Psyllidae (11 from Psyllinae and one from Macrocorsinae), using high-throughput amplicon sequencing of the 16S rRNA gene.ResultsThe analysis showed that all 12 psyllids have the primary symbiont, Candidatus Carsonella ruddii (Gammaproteobacteria: Oceanospirillales), and at least one secondary symbiont. The majority of the secondary symbionts were gammaproteobacteria, especially those of the family Enterobacteriaceae (order: Enterobacteriales). Among them, symbionts belonging to “endosymbionts3”, which is a genus-level monophyletic group assigned by the SILVA rRNA database, were the most prevalent and were found in 9 of 11 Psyllinae species. Ca. Fukatsuia symbiotica and Serratia symbiotica, which were recognized only as secondary symbionts of aphids, were also identified. In addition to other Enterobacteriaceae bacteria, including Arsenophonus, Sodalis, and “endosymbionts2”, which is another genus-level clade, Pseudomonas (Pseudomonadales: Pseudomonadaceae) and Diplorickettsia (Diplorickettsiales: Diplorickettsiaceae) were identified. Regarding Alphaproteobacteria, the potential plant pathogen Ca. Liberibacter europaeus (Rhizobiales: Rhizobiaceae) was detected for the first time in Anomoneura mori (Psyllinae), a mulberry pest. Wolbachia (Rickettsiales: Anaplasmataceae) and Rickettsia (Rickettsiales: Rickettsiaceae), plausible host reproduction manipulators that are potential tools to control pest insects, were also detected.ConclusionsThe present study identified various bacterial symbionts including previously unexpected lineages in psyllids, suggesting considerable interspecific transfer of arthropod symbionts. The findings provide deeper insights into the evolution of interactions among insects, bacteria, and plants, which may be exploited to facilitate the control of pest psyllids in the future.

High-resolution Microbiome Analyses of Nine Psyllid Species of the Family Triozidae Identified Previously Unrecognized but Major Bacterial Populations, including <i>Liberibacter</i> and <i>Wolbachia</i> of Supergroup O

Psyllids (Hemiptera: Sternorrhyncha: Psylloidea) are plant sap-sucking insects that include important agricultural pests. To obtain insights into the ecological and evolutionary behaviors of microbes, including plant pathogens, in Psylloidea, high-resolution ana-lyses of the microbiomes of nine psyllid species belonging to the family Triozidae were performed using high-throughput amplicon sequencing of the 16S rRNA gene. Analyses identified various bacterial populations, showing that all nine psyllids have at least one secondary symbiont, along with the primary symbiont "Candidatus Carsonella ruddii" (Gammaproteobacteria: Oceanospirillales: Halomonadaceae). The majority of the secondary symbionts were gammaproteobacteria, particularly those of the order Enterobacterales, which included Arsenophonus and Serratia symbiotica, a bacterium formerly recognized only as a secondary symbiont of aphids (Hemiptera: Sternorrhyncha: Aphidoidea). The non-Enterobacterales gammaproteobacteria identified in the present study were Diplorickettsia (Diplorickettsiales: Diplorickettsiaceae), a potential human pathogen, and Carnimonas (Oceanospirillales: Halomonadaceae), a lineage detected for the first time in Psylloidea. Regarding alphaproteobacteria, the potential plant pathogen "Ca. Liberibacter europaeus" (Rhizobiales: Rhizobiaceae) was detected for the first time in Epitrioza yasumatsui, which feeds on the Japanese silverberry Elaeagnus umbellata (Elaeagnaceae), an aggressive invasive plant in the United States and Europe. Besides the detection of Wolbachia (Rickettsiales: Anaplasmataceae) of supergroup B in three psyllid species, a lineage belonging to supergroup O was identified for the first time in Psylloidea. These results suggest the rampant transfer of bacterial symbionts among animals and plants, thereby providing deeper insights into the evolution of interkingdom interactions among multicellular organisms and bacteria, which will facilitate the control of pest psyllids.

First record of Heteropsylla tenuata from Argentina (Hemiptera: Psyllidae), and additional notes on other psyllid species

The Psyllidae family is the most diverse within Psylloidea, with more than 1,300 species worldwide. Some psyllid species are important pests mainly of fruit trees, forest and ornamental plants. Despite being an economically relevant group, there are few studies on its biology, geographic distribution, natural enemies or host plant associations for many Argentinean psyllid species. This work records one species from Argentina for the first time, extends the distribution of another two psyllid species and provides information on host plants.

Encapsulation of the psyllid-pathogenic fungus Pandora sp. nov. inedit. and experimental infection of target insects.

Pandora sp. nov. inedit. (Entomophthorales: Entomophthoraceae) (ARSEF 13372) is a recently isolated entomophthoralean fungus with potential for psyllid pest control. This study aimed to develop a formulation based on biocompatible hydrogel beads in order to transfer the fungus into an easily applicable form and to test the effects on psyllids. After encapsulation in calcium alginate beads, Pandora sp. nov. grew from the beads and discharged conidia over 12 days under optimal humidity conditions at 18 °C. Conidial number was increased 2.95-fold by the addition of skimmed milk as nutritional formulation adjuvant to the beads. The virulence of the encapsulated fungus was assessed with the two target psyllid species; the summer apple psyllid, Cacopsylla picta and the pear psyllid, Cacopsylla pyri. Beads containing skimmed milk as nutritional adjuvant led to the highest mortalities (48.3% on C. picta and 75.0% on C. pyri). In a second bioassay, survival time of C. pyri exposed to beads containing different concentration (10%, 20% or 40%) of Pandora sp. nov. was tested. The survival time of C. pyri was significantly reduced when exposed to beads containing 10% or 20% Pandora sp. nov. The median survival time was reached after 5-6 days past inoculation and the cumulative mortality for C. pyri treated with Pandora sp. nov. beads showed up to 89% mortality. The promising results of this study will ease the way for large-scale field application of a novel Pandora species in biological psyllid pest control.

Auchmerina (Hemiptera: Psylloidea), a psyllid genus in Brazil, associated with Inga spp. (Fabaceae)

Distributional records in Brazil are provided for two psyllid species, Auchmerina limbatipennis Enderlein, documented for the states of Paraná, Rio de Janeiro, Santa Catarina and São Paulo, and A. tuthilli Klimaszewski, for Paraná and Santa Catarina. Host plants for these species are reported for the first time. A. limbatipennis develops on Inga laurina and I. marginata (Fabaceae), and it displays a dimorphism (presence or absence of a distal dark band on the forewing), that is not sexual nor seasonal. A.tuthilli probably develops on Inga spp. As well. For the first time, the immatures of Auchmerina are described.

THE ALIEN PSYLLID MACROHOMOTOMA GLADIATA KUWAYAMA, 1908 (HEMIPTERA PSYLLOIDEA HOMOTOMIDAE): SPREAD AND DAMAGE OF A RECENTLY RECORDED PEST OF FICUS MICROCARPA TREES IN TUNISIA

During an inventory study of Psylloidea species carried out in Tunisia, the alien psyllid, Macrohomotoma gladiata Kuwayama, 1908 (Hemiptera Psylloidea Homotomidae), recently recorded in the country, has been detected on ornamental Ficus microcarpa, in public and private parks and gardens in many locations of the urban areas of the governorates of Tunis and Ariana, showing a fast spread in the area. This psyllid species has been observed causing damages and vegetative disorders to Ficus trees, especially white wax secretion, leaf wrapping and honeydew excretion on leaves and twigs. The number of infested trees increased from our first observations in late 2020 to early 2021. An Anthocoris sp. (Hemiptera Anthocoridae) has been observed to naturally prey on M. gladiata in many investigated locations.

Uncovering Symbionts Across the Psyllid Tree of Life and the Discovery of a New Liberibacter Species, "Candidatus" Liberibacter capsica.

Sap-feeding insects in the order Hemiptera associate with obligate endosymbionts that are required for survival and facultative endosymbionts that can potentially modify resistance to stress, enemies, development, and reproduction. In the superfamily Psylloidea, the jumping plant lice (psyllids), less is known about the diversity and prevalence of their endosymbionts compared to other sap-feeding pests such as aphids (Aphididae). To address this knowledge gap, using 16S rRNA sequencing we identify symbionts across divergent psyllid host lineages from around the world. Taking advantage of a new comprehensive phylogenomic analyses of Psylloidea, we included psyllid samples from 44 species of 35 genera of five families, collected from 11 international locations for this study. Across psyllid lineages, a total of 91 OTUs were recovered, predominantly of the Enterobacteriaceae (68%). The diversity of endosymbionts harbored by each psyllid species was low with an average of approximately 3 OTUs. Two clades of endosymbionts (clade 1 and 2), belonging to Enterobacteriaceae, were identified that appear to be long term endosymbionts of the psyllid families Triozidae and Psyllidae, respectively. We also conducted high throughput metagenomic sequencing on three Ca. Liberibacter infected psyllid species (Russelliana capsici, Trichochermes walkeri, and Macrohomotoma gladiata), initially identified from 16S rRNA sequencing, to obtain more genomic information on these putative Liberibacter plant pathogens. The phylogenomic analyses from these data identified a new Ca. Liberibacter species, Candidatus Liberibacter capsica, that is a potential pathogen of solanaceous crops. This new species shares a distant ancestor with Ca. L. americanus, which occurs in the same range as R. capsici in South America. We also detected the first association between a psyllid specializing on woody hosts and the Liberibacter species Ca. L. psyllaurous, which is a globally distributed pathogen of herbaceous crop hosts in the Solanaceae. Finally, we detected a potential association between a psyllid pest of figs (M. gladiata) and a Ca. Liberibacter related to Ca. L. asiaticus, which causes severe disease in citrus. Our findings reveal a wider diversity of associations between facultative symbionts and psyllids than previously reported and suggest numerous avenues for future work to clarify novel associations of ecological, evolutionary, and pathogenic interest.

Description of an Australian endemic species of Trioza (Hemiptera: Triozidae) pest of the endemic tea tree, Melaleuca alternifolia (Myrtaceae).

Psyllids, also known as jumping plant lice, are phloem feeding Hemiptera that often show a strict species-specific relationship with their host plants. When psyllid-plant associations involve economically important crops, this may lead to the recognition of a psyllid species as an agricultural or horticultural pest. The Australian endemic tea tree, Melaleuca alternifolia (Maiden & Betche) Cheel., has been used for more than a century to extract essential oils and, long before that, as a traditional medicine by Indigenous Australian people. Recently, a triozid species has been found to damage the new growth of tea trees both in Queensland and New South Wales, raising interest around this previously undocumented pest. Furthermore, adults of the same species were also collected from Citrus plantations, leading to potential false-positive records of the exotic pest Trioza erytreae (Del Guercio 1918), the African Citrus psyllid. Here we describe for the first time Trioza melaleucae Martoni sp. nov. providing information on its distribution, host plant associations and phylogenetic relationships to other Trioza species. This work enables both morphological and molecular identification of this new species, allowing it to be recognized and distinguished for the first time from exotic pests as well as other Australian native psyllids. Furthermore, the haplotype network analysis presented here suggests a close relationship between Trioza melaleucae and the other Myrtaceae-feeding Trioza spp. from Australia, New Zealand, and Taiwan.

IN1329] Fig Psyllid Homotoma ficus (L.) (Insecta: Hemiptera: Homotomidae); Curtain Fig Psyllid Macrohomotoma gladiata Kuwayama (Insecta: Hemiptera: Homotomidae); and Ficus Leaf-Rolling Psyllid Trioza brevigenae Mathur (Insecta: Hemiptera: Triozidae)

This article details three adventive (to North America) psyllid species that feed on ficus. Homotoma ficus (the fig psylla) was noticed first in 1969, and Macrohomotoma gladiata (the curtain fig psyllid) and Trioza brevigenae (the ficus leaf rolling psyllid) were found to be present in 2015 and 2016, respectively. All three three species are currently found only in California, but could possibly spread to other states including Florida in the future.

High-altitude migration of Psylloidea (Hemiptera) over England

Some species of psyllid (Hemiptera: Psylloidea) are known to make high-altitude windborne migrations, but compared with their sister superfamily, the Aphidoidea, our knowledge of these movements is rudimentary and unsystematised. Here we have extracted psyllid capture data from day and night aerial sampling carried out at a height of 200 m above ground at Cardington, Bedfordshire, UK, during summers between 1999 and 2007. These records were consolidated with high-altitude psyllid catches made over England during the 1930s and with some other trapping results from northwest Europe which were indicative of migration. Information on aerial densities, diel flight periodicity, and the sex-ratio of the aerial psyllid populations is presented. We also compared our results with those of a recent study which used the Rothamsted Insect Survey network of suction traps (sampling at a height of 12.2 m); this provided confirmative evidence that the suction-traps were indeed detecting migrating psyllids. Finally, both aerial netting and suction trap data were used to tentatively interpret the seasonal timing of migrations in terms of the breeding/overwintering cycles of some common psyllid species.

First record of Heterotrioza chenopodii (Reuter, 1876) (Hemiptera: Psylloidea: Triozidae) in Tunisia

AbstractThis is the first report of the psyllid species, Heterotrioza chenopodii (Reuter, 1876), in Tunisia. This species was collected in November 2019 on Chenopodium album growing in the greenhouse of the Higher School of Agriculture, Kef, Northwestern Tunisia. Elements of colouration of adults and immatures are reported in this paper and considerations about the use of this species as a weed biocontrol agent are discussed.

Two new records of jumping plant lice (Hemiptera: Triozidae) from Syria

AbstractDuring regular inspections of plants in the Latakia Governorate, Syria, two psyllid species previously unknown from Syria were discovered. These are Phylloplecta trisignata (Löw) from Rubus sp. and Trioza brevigenae Mathur from Ficus microcarpa. Both are new records for Syria. For T. brevigenae this is also only the second record of this species in the EPPO region, the previous one being a new record in Cyprus in 2020.

Biology of Pseudophacopteron pusillum and Pseudophacopteron eastopi (Hemiptera- Psylloidea: Phacopteronidae), pest of Dacryodes edulis (Burseraceae) in Yaounde, Cameroon

Dacryodes edulis (Burseraceae) is an important plant native from Central Africa. In Cameroon, it is cultivated in almost all regions for economic, medicinal and nutritional purposes. D. edulis is visited by four psyllid species: Pseudophacopteron serrifer, P. tamessei, P. eastopi and P. pusillum. Those psyllids cause important damages on their host plant, necessitating to put in place an integrated pest control against them. The aim of this survey is to study the biology of P. pusillum and P. eastopi on D. edulis in the nursery, which is helpful for an integrated pest management. The study was carried out from April 2011 to March 2012 through daily observations. It is observed that the two psyllid species are sharing different sites on their host plant to lay eggs. The eggs hatching and develop through five instar larval stages before become adult. The fertility, adult life span, sexual maturity, and the developmental duration of each instar larva were determined.

Psyllids (Hemiptera: Psylloidea) associated with Ficus vallis-choudae (Moraceae) in southern Cameroon: taxonomy and biology

Homotoma chlamydodoraHollis & Bromfield, 1989 (Homotomidae) and Pauropsylla tatricheaHollis, 1984 (Triozidae) are two poorly known psyllid species that develop on Ficus vallis-choudae. Based on material collected within the framework of biodiversity studies of psyllids (Hemiptera: Psylloidea) associated with Ficus spp. (Moraceae) in Cameroon, the taxonomy of the two psyllid species is revised and information on the biology is provided. In particular the previously unknown immatures of both species and the male of P. tatrichea are described and illustrated here. A tubercular process on the mesocoxa of P. tatrichea, a putative autapomorphy of PauropsyllaRübsaamen, 1899 is described here for the first time. Both species are polyvoltine with overlapping generations. Immatures of H. chlamydodora develop under the stipules whereas those of P. tatrichea induce pit galls on the leaves. Both species appear to be restricted to Ficus vallis-choudae, at least locally.

Stylet Probing Behavior of Two Bactericera (Hemiptera: Psylloidea: Triozidae) Species on Host and Nonhost Plants.

Understanding host use by psyllids (Hemiptera: Psylloidea) benefits from comparative studies of behavior on host and nonhost plant species. While most psyllid species develop on one or a few closely related plant species, some species are generalized enough to develop on species across plant families. We used electropenetography (EPG) technology to compare probing activities of an oligophagous psyllid (Bactericera cockerelli (Šulc)) and a host-specialized psyllid (Bactericera maculipennis) on two species of Solanaceae (potato, Solanum tuberosum L. and matrimony vine, Lycium barbarum L.) and two species of Convolvulaceae (field bindweed, Convolvulus arvensis L. and sweet potato, Ipomoea batatas). Bactericera cockerelli develops on all four species, albeit with longer development times on Convolvulaceae. Bactericera maculipennis develops only on Convolvulaceae. Bactericera cockerelli fed readily from phloem of all four species, but the likelihood of entering phloem and duration of time in phloem was reduced on suboptimal hosts (Convolvulaceae) relative to behavior on Solanaceae. We observed instances of cycling between bouts of phloem salivation and ingestion in assays of optimal (Solanaceae) hosts not observed on Convolvulaceae. The Convolvulaceae-specialized B. maculipennis (Crawford) failed to feed from phloem of nonhosts (Solanaceae). Both psyllid species readily ingested from xylem of all plant species, irrespective of host status. Our finding that phloem feeding by B. maculipennis did not occur on potato has implications for understanding epidemiology of phloem-limited psyllid-vectored plant pathogens. Our results also showed that EPG assays detect subtle variation in probing activities that assist in understanding host use by psyllids.

Prvi nalazi vrsta Acizzia uncatoides (Ferris & Klyver, 1932) i Acizzia acaciaebaileyanae (Froggatt, 1901) (Hemiptera: Psylloidea: Psyllidae) u Hrvatskoj

Alien species represent a significant component of European entomofauna. Intensive international trade of plants, particularly woody ornamentals, has increased introduction of alien species into Europe in the last two decades, where alien terrestrial invertebrates prevail as one of the most numerous groups of introduced organisms. As of 2010, fourteen species of alien psyllids (Hemiptera: Psylloidea) have been recorded in Europe. Five species have been reported from Croatia, including Acizzia jamatonica (Kuwayama, 1908), as the only species from genus Acizzia Heslop-Harrison, 1961 present in Croatia so far. This paper provides genus status in Croatia, with first records of Australian species Acizzia uncatoides (Ferris & Klyver, 1932) and Acizzia acaciaebaileyanae (Froggatt, 1901).

De novo assembly and comparative analysis of the complete mitochondrial genome sequence of the pistachio psyllid, Agonoscena pistaciae (Hemiptera: Aphalaridae)

The pistachio psyllid, Agonoscena pistaciae, is one of the most deleterious pests of pistachio trees. Deciphering genetic diversity and population structure is a prerequisite for developing efficacious suppression protocols and successful management strategies for any insect pest including A. pistaciae. Mitochondrial genome sequencing furnishes valuable information about insect evolution and diversity within and among populations. Here, we assembled the first complete mitochondrial genome of the pistachio psyllid high-throughput next generation sequencing. The circular mitochondrial genome of A. pistaciae was 15,346 bp in length encoding 37 genes, including 13 protein-coding genes (PCGs), 2 rRNA genes and 22 tRNA genes, with a long non-coding region (putative control regions). The A. pistaciae mitogenome was in same typical set and arrangement as that of the ancestral insect. The mitochondrial genome of A. pistaciae was compared to all 6 publically available mitogenomes of other Psylloidea species. The conservation of the gene arrangements and identical gene ordering among all psyllid species could suggest a structurally common ancestral mitogenome shared across Psylloidea. Phylogenetic analysis based on the 13 PCGs conformed the existing morphological based taxonomy and showed the clustering of the two Aphalaridae. Whole mitochondrial genome of A. pistaciae could be utilized in subsequent population genetic studies of the species and also add to a deeper understanding of the phylogenetic research links within the subfamily Psylloidea.

Population dynamic of <i>Diclidophlebia irvingiae</i>, Burckhardt et al. (Hemiptera: Psylloidea), psyllid pest of <i>Irvingia gabonensis</i> Baill (Irvingiaceae, Rutales) in Bamenda, North-West region of Cameroon

Diclidophlebia irvingiae is a sap-sucking insect of Irvingia gabonensis inducing important damage to its host plant which has medicinal and nutritional importance in Africa particularly in Cameroon. The aim of the survey was to study numerical variation of the pest during the year and impact of biotic and abiotic factors on numerical variation. The study was carried in Bamenda from March 2018 to March 2019 where larvae and adults of D. irvingiae were collected monthly. The study permitted us to record 3290 individuals 1341 males, 1396 females and 553 larvae. Population fluctuation of the pest during the year showed five periods of individual outbreak corresponding to the generation number of the pest. As most tropical and sub-tropical psyllid species D. irvingiae is a multivoltine species with five annual generations. The outbreak periods depend principally on the phenology of host plant. The statistical test showed that the numerical individual variation of D. irvingiae is not directly related to climatic factors because they do not show significant probability.Keywords: Impact, Biotic, Abiotic, Factors, Insect, Faunistic.

Effect of Daytime and Tree Canopy Height on Sampling of Cacopsylla melanoneura, a 'Candidatus Phytoplasma mali' Vector.

The psyllids Cacopsylla melanoneura and Cacopsylla picta reproduce on apple (Malus × domestica) and transmit the bacterium ‘Candidatus Phytoplasma mali’, the causative agent of apple proliferation. Adult psyllids were collected by the beating-tray method from lower and upper parts of the apple tree canopy in the morning and in the afternoon. There was a trend of catching more emigrant adults of C. melanoneura in the morning and in the lower part of the canopy. For C. melanoneura remigrants, no differences were observed. The findings regarding the distribution of adults were reflected by the number of nymphs collected by wash-down sampling. The density of C. picta was too low for a statistical analysis. The vector monitoring and how it is commonly performed, is suitable for estimating densities of C. melanoneura. Nevertheless, above a certain temperature threshold, prediction of C. melanoneura density might be skewed. No evidence was found that other relatively abundant psyllid species in the orchard, viz. Baeopelma colorata, Cacopsylla breviantennata, Cacopsylla brunneipennis, Cacopsylla pruni and Trioza urticae, were involved in ‘Candidatus Phytoplasma mali’ transmission. The results of our study contribute to an advanced understanding of insect vector behavior and thus have a practical impact for an improved field monitoring.

Characterization of the bacterial communities of psyllids associated with Rutaceae in Bhutan by high throughput sequencing

BackgroundSeveral plant-pathogenic bacteria are transmitted by insect vector species that often also act as hosts. In this interface, these bacteria encounter plant endophytic, insect endosymbiotic and other microbes. Here, we used high throughput sequencing to examine the bacterial communities of five different psyllids associated with citrus and related plants of Rutaceae in Bhutan: Diaphorina citri, Diaphorina communis, Cornopsylla rotundiconis, Cacopsylla heterogena and an unidentified Cacopsylla sp.ResultsThe microbiomes of the psyllids largely comprised their obligate P-endosymbiont ‘Candidatus Carsonella ruddii’, and one or two S-endosymbionts that are fixed and specific to each lineage. In addition, all contained Wolbachia strains; the Bhutanese accessions of D. citri were dominated by a Wolbachia strain first found in American isolates of D. citri, while D. communis accessions were dominated by the Wolbachia strain, wDi, first detected in D. citri from China. The S-endosymbionts from the five psyllids grouped with those from other psyllid taxa; all D. citri and D. communis individuals contained sequences matching ‘Candidatus Profftella armatura’ that has previously only been reported from other Diaphorina species, and the remaining psyllid species contained OTUs related to unclassified Enterobacteriaceae. The plant pathogenic ‘Candidatus Liberibacter asiaticus’ was found in D. citri but not in D. communis. Furthermore, an unidentified ‘Candidatus Liberibacter sp.’ occurred at low abundance in both Co. rotundiconis and the unidentified Cacopsylla sp. sampled from Zanthoxylum sp.; the status of this new liberibacter as a plant pathogen and its potential plant hosts are currently unknown. The bacterial communities of Co. rotundiconis also contained a range of OTUs with similarities to bacteria previously found in samples taken from various environmental sources.ConclusionsThe bacterial microbiota detected in these Bhutanese psyllids support the trends that have been seen in previous studies: psyllids have microbiomes largely comprising their obligate P-endosymbiont and one or two S-endosymbionts. In addition, the association with plant pathogens has been demonstrated, with the detection of liberibacters in a known host, D. citri, and identification of a putative new species of liberibacter in Co. rotundiconis and Cacopsylla sp.