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We produced an extract of Melia azedarach and assessed its potential for managing health problems in Eucalyptus nurseries. We assessed different extraction parameters, looking for maximizing extraction efficiency. The enhanced percolation technique showed an efficient extraction process, facilitated using bioethanol as a solvent at room temperature. We carried out field trials to check the efficacy of the extract. We observed a decreased severity and incidence of powdery mildew after application of the extract, and a reduction in the infestation of B. occidentalis. These results highlight the potential of this extract as a sustainable alternative to chemical biocides. [ABSTRACT FROM AUTHOR]

Abstract Chemical insecticides increased the chemical burden on natural ecosystems posing environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, including eco-friendly ‘genetic zipper’ method (or CUAD platform) based on contact oligonucleotide insecticides. Oligonucleotide insecticides have enjoyed success recently on many sternorrhynchans showing highly adaptable structure for distinct insect pest species and selective mode of action. In this article, we describe the efficiency of the oligonucleotide insecticides (briefly, olinscides or DNA insecticides) Alacris-11 and Laura-11, as well as their combined use in mixture (1:1), designed for control of bay sucker (Trioza alacris Flor), an important psyllid pest of noble laurel (Laurus nobilis L.). These olinscides are based on short unmodified antisense DNA oligonucleotides that target ITS2 between 5.8S rRNA and 28S rRNA in pre-rRNA (Laura-11) and 28S rRNA region in mature 28S rRNA and pre-rRNA (Alacris-11). The maximum pest mortality, observed on the 14th day of the experiment, comprised 95.01 ± 4.42% for Alacris-11, 97.16 ± 2.48% for Laura-11, and 98.72 ± 1.14% for their mixture (1:1). The control oligonucleotide CTGA-11 did not cause any significant mortality (9.38 ± 0.57%), emphasizing selectivity in the action of oligonucleotide insecticides. The results show potent and specific nature of oligonucleotide insecticides for pest control and open up new frontiers in control of economically important psyllids in agriculture and forestry, including Asian citrus psyllid (Diaphorina citri Kuwayama) and many others. Scientists can easily adopt ‘genetic zipper’ method for plethora of insect pests because DNA is a programmable molecule and provides game-changing characteristics for plant protection. Graphical Abstract

Simple Summary: Correct taxonomic identification is essential for conducting successful biological research, especially with regard to economically important insects, such as jumping plant lice or psyllids. In the present study, we identify and diagnose the morphologically characterised aphalarid species from Bulgaria using two molecular markers, cytochrome c oxidase I and cytochrome b. A total of 80 sequences of 25 Aphalaridae species were obtained and included in the BOLD and GenBank databases. This should enable even non-experts to identify these species quickly and accurately. The results of the current study show that two barcode genes are sufficient to distinguish most aphalarid species. Psyllids (Hemiptera: Psylloidea) are plant sap-sucking insects whose identification is often difficult for non-experts. Despite the rapid development of DNA barcoding techniques and their widespread use, only a limited number of sequences of psyllids are available in the public databases, and those that are available are often misidentified. Here, we provide 80 sequences of two mitochondrial genes, cytochrome c oxidase I (COI) and cytochrome b (Cytb), for 25 species of Aphalaridae, mainly from Bulgaria. The DNA barcodes for 15 of these species are published for the first time. In cases where standard primers failed to amplify the target gene fragment, we designed new primers that can be used in future studies. The distance-based thresholds for the analysed species were between 0.0015 and 0.3415 for COI and 0.0771 and 0.4721 for Cytb, indicating that the Cytb gene has a higher interspecific divergence, compared to COI, and therefore allows for more accurate species identification. The species delimitation based on DNA barcodes is largely consistent with the differences resulting from morphological and host plant data, demonstrating that the use of DNA barcodes is suitable for successful identification of most aphalarid species studied. The phylogenetic reconstruction based on maximum likelihood and Bayesian inference analyses, while showing similar results at high taxonomic levels to previously published phylogenies, provides additional information on the placement of aphalarids at the species level. The following five species represent new records for Bulgaria: Agonoscena targionii, Aphalara affinis, Colposcenia aliena, Co. bidentata, and Craspedolepta malachitica. Craspedolepta conspersa is reported for the first time from the Czech Republic, while Agonoscena cisti is reported for the first time from Albania. [ABSTRACT FROM AUTHOR]

The use of individual protective covers (IPCs) to protect newly planted citrus trees from Huanglongbing (HLB) infection is being widely adopted in Florida, an HLB-endemic citrus-producing area. It is known that IPCs positively influence most horticultural traits, increasing tree growth, flush expansion, and leaf size, enabling trees to sustain balanced carbohydrate metabolism by preventing Candidatus Liberibacter asiaticus (CLas) infection, and inducing higher leaf chlorophyll levels. This may result in more productive trees. However, as the tree grows, IPCs eventually are removed, typically between 2 and 3 years after their initial installation. Once IPCs are removed, trees become exposed to the Asian citrus psyllid (ACPs) and ultimately become infected. In this work, we covered Valencia sweet orange trees with IPCs for 30 months, until the trees entered fruit-bearing age. We investigated how the IPC protection of newly planted trees for 30 months influenced the fruit quality and yield of "Valencia" trees for three consecutive seasons after IPC removal compared to non-covered trees. The use of IPCs kick-started the newly planted citrus trees, resulting in higher yields and fruits with better internal and external quality. After 30 months of IPC protection, tree canopies were larger and denser, supporting more fruit per tree than non-protected trees for three consecutive seasons, even though by the end of the first season after IPC removal, the trees were HLB-positive. Tree height, scion diameter, canopy volume, and leaf area were significantly improved compared to non-covered trees. Additionally, fruit quality was significantly improved in the three seasons following IPC removal compared to non-covered trees. However, a decline in quality was measurable in fruit from IPC trees after the second harvesting season, with trees affected by HLB. Based on the results from this study, we conclude that the benefits from IPC protection may last for at least three consecutive seasons once trees enter the productive age, despite CLas infection within 12 months after IPC removal. [ABSTRACT FROM AUTHOR]

Using molecular (COI , Cytb , H3 , wg , 12S, 16S, and 28S) and morphological data (61 characters of adults and immatures), the phylogenetic relationships of the 20 nominal genera of Liviinae were analysed, and the monophyly of the subfamily was tested relative to the other two subfamilies of Liviidae. The analyses of the molecular, morphological, and combined datasets provided similar results with a strong or moderate support in the molecular and combined analyses for the subfamilies of Liviidae and two clades in Liviinae given tribal rank (Liviini and Paurocephalini stat. rev.). Three of the six previously recognized genera were confirmed as monophyletic (Aphorma , Camarotoscena , and Livia) and three were shown to be polyphyletic: Diclidophlebia s.l. (Diclidophlebia s.s. , Haplaphalara stat. rev. Klyveria Burckhardt, Serbina and Malenovský, gen. nov. Melanastera Serbina, Malenovský, Queiroz and Burckhardt, gen. nov. and Woldaia stat. rev.), Paurocephala s.l. (Liella Burckhardt, Serbina and Malenovský, gen. nov. and Paurocephala s.s.), and Syntomoza s.l. (Anomoterga stat. rev. and Syntomoza s.s.). The new generic definitions require 38 new and eight revived combinations, including the transfer of two species to other families. All genera of Liviinae are diagnosed and keys are provided for their identification. A checklist of world Liviinae is supplemented. [ABSTRACT FROM AUTHOR]

Phytoplasmas are bacterial pathogens located in the plant's phloem that are responsible for several plant diseases and are mainly transmitted by phloem-sucking insects. Apple proliferation (AP) is an economically important disease associated with the presence of 'Candidatus Phytoplasma mali' which is transmitted by two psyllid species. While Cacopsylla picta is a vector in different regions, the vector efficiency of C. melanoneura varies between different populations. This species is considered the main AP vector in Northwestern Italy but plays a minor role in Northeastern Italy and other European regions. To investigate whether the psyllid and/or the phytoplasma subtype drive the phytoplasma acquisition in C. melanoneura, a phytoplasma acquisition experiment was set up using single mating couples of overwintered individuals from different psyllid populations and phytoplasma subtypes. All analyzed insect populations acquired phytoplasma, but with different efficiencies and concentrations. The main factors driving the acquisition were the phytoplasma subtype and its concentration in the leaves of the infected trees together with the psyllid lineage. The phytoplasma concentration in the psyllids was again influenced by the phytoplasma subtype, the psyllid lineage and the region of origin, whereas the phytoplasma concentration in the leaves and the psyllid haplotype defined with the cytochrome oxidase I gene had only a minor impact on the phytoplasma concentration. This is the first study evaluating the roles of both the psyllid haplotype and the phytoplasma subtype on the acquisition process and highlights the importance of C. melanoneura as an additional AP vector. [ABSTRACT FROM AUTHOR]

The goji berry psyllid, Bactericera gobica Logniova (Homoptera: Psyllidae), is one of the most important pests on goji berry plants (Lycium barbarum L.), whose fruits are widely used in traditional Chinese medicine and food. However, chemical control is still the predominant control strategy of this pest. Recently, two species of predatory mites, Neoseiulus setarius Ma, Meng & Fan and Neoseiulus barkeri Hughes were found to be associated with B. gobica in China. To assess their predation potential against B. gobica, the functional responses of these two phytoseiid species feeding on different densities (2, 4, 8, 12, 16, 24 and 32 individuals) of B. gobica eggs and 1st instar nymphs were compared at a temperature of 25ºC ± 1º C. Logistic regression analysis revealed that both predatory mite species exhibited type Holling-II functional responses on eggs and 1st instar nymphs of B. gobica, with the predation number increased for both predators as the density of prey increased. Overall, N. setarius consumed more prey compared to N. barkeri across all levels of prey densities. Meanwhile, the highest attack rate (α = 0.0283), the lowest handling time (Th = 1.1324 h prey− 1), and the highest estimated maximum predation rate (T/Th = 21.19 prey day− 1) were all observed for N. setarius fed with 1st instar nymphs of B. gobica. These findings suggest that it is worthy considering utilizing N. setarius and N. barkeri as candidate biocontrol agents of B. gobica, with N. setarius appearing to be a more effective predator than N. barkeri. [ABSTRACT FROM AUTHOR]

During field surveys conducted in 2021 in western Jordanian heights, phytoplasma-like symptoms were observed, including leaf reddening along with slow decline in pear (pear decline symptoms) and leaf yellowing followed by scorch in apple trees. Abundant populations of the psyllid Cacopsylla bidens were found in the pear trees. Nested PCR amplifying 16S rDNA detected phytoplasmas in 63% and 36% of symptomatic pear and apple samples, respectively, and in 46% of pooled C. bidens specimens. No phytoplasmas were detected in symptomless plant samples. PCR product nucleotide sequence analyses attributed the phytoplasmas detected in pear to 'Candidatus Phytoplasma pyri', 'Ca. P. solani', 'Ca. P. omanense', and 'Ca. P. aurantifolia', and those identified in apple to 'Ca. P. solani' and 'Ca. P. omanense'. All phytoplasma strains identified in C. bidens were attributed to 'Ca. P. pyri'. To the best of our knowledge, this is the first report of phytoplasmas associated with pear and apple diseases, including pear decline, in Jordan. Even though a limited number of pome fruit samples were analyzed, a surprising diversity was found among detected phytoplasmas. Further studies will be carried out to investigate the complex etiology of such diseases, and the 'Ca. P. pyri' vectoring activity of C. bidens. [ABSTRACT FROM AUTHOR]

In a survey of the arthropod fauna of 33 Urban Green Spaces (UGS) in Bogotá, Colombia, between 2017 and 2019, 21 species (3,825 specimens) of Psylloidea were collected. These represent all seven recognised families of jumping plant-lice and include seven species identified only to genus. The specimens, all adults, were collected on 30 plant species used for arborization in the UGS. Two species are described as new (Mastigimas longicaudatus Rendón-Mera, Burckhardt & Vargas-Fonseca, sp. nov. and Leuronota albilinea Rendón-Mera, Burckhardt & Vargas-Fonseca, sp. nov.), one species is redescribed (Mastigimas colombianus Burckhardt, Queiroz & Drohojowska) and one species is recorded for the first time from Colombia (Calinda trinervis Olivares & Burckhardt). Among the seven species identified only to genus is an undescribed species of Melanastera, representing a genus not previously known from Colombia. Fourteen species found during the survey are probably native (66%) and seven (33%) adventive. Our findings highlight the significance of UGS for preservation of biological diversity and stress the importance of using native plants in urban landscape planning for the conservation of the native entomofauna. [ABSTRACT FROM AUTHOR]

Abstract Objectives DNA Barcoding has proven to be a reliable method for rapid insect identification. The success of this method is based on the amplification of a specific region, the ‘Folmer’ barcode region at the 5´ start of the cytochrome c oxidase 1 gene (cox1), with universal primers. Previous studies showed failures of standard “universal” primers to amplify this region in psyllids. The aim of the study was the design of a new alternative more reliable primer combination for taxa of the superfamily Psylloidea and its comparison with the performance of the standard “universal” Folmer-primers. Results A newly designed degenerate forward primer LCOP-F was developed following comparison of the sequence alignment of the priming site of “universal” primer LCO1490 and the standard insect forward primer LepF1. When combined with the “universal” reverse primer, HCO2198, this new primer pairing was able to generate barcode sequence for all 36 species in 20 genera across the five families of psyllids tested in this study, and these primers were found to be more universally reliable across psyllid taxa than other primer pairs tested.

The use of individual protective covers (IPCs) to protect newly planted citrus trees from Huanglongbing (HLB) infection is being widely adopted in Florida, an HLB-endemic citrus-producing area. It is known that IPCs positively influence most horticultural traits, increasing tree growth, flush expansion, and leaf size, enabling trees to sustain balanced carbohydrate metabolism by preventing Candidatus Liberibacter asiaticus (CLas) infection, and inducing higher leaf chlorophyll levels. This may result in more productive trees. However, as the tree grows, IPCs eventually are removed, typically between 2 and 3 years after their initial installation. Once IPCs are removed, trees become exposed to the Asian citrus psyllid (ACPs) and ultimately become infected. In this work, we covered Valencia sweet orange trees with IPCs for 30 months, until the trees entered fruit-bearing age. We investigated how the IPC protection of newly planted trees for 30 months influenced the fruit quality and yield of “Valencia” trees for three consecutive seasons after IPC removal compared to non-covered trees. The use of IPCs kick-started the newly planted citrus trees, resulting in higher yields and fruits with better internal and external quality. After 30 months of IPC protection, tree canopies were larger and denser, supporting more fruit per tree than non-protected trees for three consecutive seasons, even though by the end of the first season after IPC removal, the trees were HLB-positive. Tree height, scion diameter, canopy volume, and leaf area were significantly improved compared to non-covered trees. Additionally, fruit quality was significantly improved in the three seasons following IPC removal compared to non-covered trees. However, a decline in quality was measurable in fruit from IPC trees after the second harvesting season, with trees affected by HLB. Based on the results from this study, we conclude that the benefits from IPC protection may last for at least three consecutive seasons once trees enter the productive age, despite CLas infection within 12 months after IPC removal.

Understanding the cues used by insects to select their hosts is essential for developing sustainable control strategies, particularly for plant disease vectors. Pear psyllids (Cacopsylla pyri) are vectors of the bacterial disease pear decline caused by 'Candidatus Phytoplasma pyri'. Yellow sticky traps are typically used to monitor pest insects, but they are non‐specific and capture many beneficial insects, too. Against the background of improving visual traps, this research aimed to investigate the colour choice behaviour of C. pyri. Our first approach was to screen insect colour preferences by performing choice assays with different LED colour wavelengths in a small‐scale choice arena under controlled conditions. Over six LEDs tested, there was a strong significant preference of C. pyri for green 1 (532 nm) followed by green 2 (549 nm). Yellow (576 nm), orange (593 nm), red 1 (619 nm) and red 2 (633 nm) were less attractive than green. Subsequently, the trapping of pear psyllids was tested in the field using newly developed traps covered with transparent‐coloured PVC sheets with a similar wavelength of the preferred LEDs. Red and completely transparent traps have been used as control and combined in randomized blocks in a pear orchard. Field trials revealed that green traps ranging from 525 to 537 nm attracted significantly more pear psyllids than longer wavelength green (543 nm), red and transparent ones. The construction of specific green‐coloured sticky traps seems promising for improving psyllid trapping, especially during an early infestation at low population densities. Thus, these visual traps should be considered in future and integrated into psyllid monitoring as part of integrated pest management. [ABSTRACT FROM AUTHOR]

Objectives: DNA Barcoding has proven to be a reliable method for rapid insect identification. The success of this method is based on the amplification of a specific region, the 'Folmer' barcode region at the 5´ start of the cytochrome c oxidase 1 gene (cox1), with universal primers. Previous studies showed failures of standard "universal" primers to amplify this region in psyllids. The aim of the study was the design of a new alternative more reliable primer combination for taxa of the superfamily Psylloidea and its comparison with the performance of the standard "universal" Folmer-primers. Results: A newly designed degenerate forward primer LCOP-F was developed following comparison of the sequence alignment of the priming site of "universal" primer LCO1490 and the standard insect forward primer LepF1. When combined with the "universal" reverse primer, HCO2198, this new primer pairing was able to generate barcode sequence for all 36 species in 20 genera across the five families of psyllids tested in this study, and these primers were found to be more universally reliable across psyllid taxa than other primer pairs tested. [ABSTRACT FROM AUTHOR]

ABSTRACT Hemipteran insects are well-known for their ancient associations with beneficial bacterial endosymbionts, particularly nutritional symbionts that provide the host with essential nutrients such as amino acids or vitamins lacking in the host’s diet. Therefore, these primary endosymbionts enable the exploitation of nutrient-poor food sources such as plant sap or vertebrate blood. In turn, the strictly host-associated lifestyle strongly impacts the genome evolution of the endosymbionts, resulting in small and degraded genomes. Over time, even the essential nutritional functions can be compromised, leading to the complementation or replacement of an ancient endosymbiont by another, more functionally versatile bacterium. Herein, we provide evidence for a dual primary endosymbiosis in several psyllid species. Using metagenome sequencing, we produced the complete genome sequences of both the primary endosymbiont “Candidatus Carsonella ruddii” and an as yet uncharacterized Enterobacteriaceae bacterium from four species of the genus Cacopsylla. The latter represents a new psyllid-associated endosymbiont clade for which we propose the name “Candidatus Psyllophila symbiotica.” Fluorescent in situ hybridization confirmed the co-localization of both endosymbionts in the bacteriome. The metabolic repertoire of Psyllophila is highly conserved across host species and complements the tryptophan biosynthesis pathway that is incomplete in the co-occurring Carsonella. Unlike co-primary endosymbionts in other insects, the genome of Psyllophila is almost as small as the one of Carsonella, indicating an ancient co-obligate endosymbiosis rather than a recent association to rescue a degrading primary endosymbiont. IMPORTANCE Heritable beneficial bacterial endosymbionts have been crucial for the evolutionary success of numerous insects by enabling the exploitation of nutritionally limited food sources. Herein, we describe a previously unknown dual endosymbiosis in the psyllid genus Cacopsylla, consisting of the primary endosymbiont “Candidatus Carsonella ruddii” and a co-occurring Enterobacteriaceae bacterium for which we propose the name “Candidatus Psyllophila symbiotica.” Its localization within the bacteriome and its small genome size confirm that Psyllophila is a co-primary endosymbiont widespread within the genus Cacopsylla. Despite its highly eroded genome, Psyllophila perfectly complements the tryptophan biosynthesis pathway that is incomplete in the co-occurring Carsonella. Moreover, the genome of Psyllophila is almost as small as Carsonella’s, suggesting an ancient dual endosymbiosis that has now reached a precarious stage where any additional gene loss would make the system collapse. Hence, our results shed light on the dynamic interactions of psyllids and their endosymbionts over evolutionary time.

The African citrus psyllid, Trioza erytreae (Del Guercio) (Hemiptera, Triozidae), is native to tropical Africa and invasive species in North America and Europe. The main host plants are citrus, displaying a preference for lemon trees. This psyllid was recently detected in the northwest region of the Iberian Peninsula, both in Spain and Portugal. Here, we used a model combining a reaction-diffusion model to a stochastic longdistance dispersal model to simulate the invasion dynamics of T. erytreae in Portugal. The psyllid spread in Portugal was simulated between 2015 and 2021 for different combinations of model parameters: two fecundity levels; spread with and without stochastic long-distance dispersal; single or two introductions of T. erytreae; and considering or not the urban and peri-urban citrus trees, besides citrus orchards, estimated using Google Street view imagery. The incorporation of long-distance human mediated dispersal significantly improved the F1-score in the model validation using the official reports as the observed data. Concomitantly, the dispersal rate of T. erytreae in Portugal was on average about 66 km/year, whereas removing long-distance dispersal events, the observed mean was 7.8 ± 0.3 km/year. The dispersal was mainly towards the south along the coastline, where human population is concentrated. The inclusion of the estimated citrus trees outside orchards areas significantly increased the F1-score in the model validation, revealing the importance these isolated host plants hold as stepping stones for the species current invasion and possibly for other species alike. [ABSTRACT FROM AUTHOR]

Sowing cover crops that supply food resources in landscapes is a potential habitat management practice for improving the biodiversity of arthropods in parks; however, little is known about their relative performance. In this study, the impact of landscape management was assessed on communities of Psyllopsis and natural enemies on the common ash (Fraxinus excelsior L.) over two growing seasons (2019 and 2020) in the Shorabil park, Iran. Experimental treatments were cultivating of (1) red clover (C), Trifolium pratense L., (2) rosemary (R), Rosmarinus officinalis L., (3) ornamental cabbage (O), Brassica oleracea L. var. acephala, and (4) grass (G), a composing of Poa pratensis L., Lolium perenne L., and Festuca rubra L. in 4:4:2 ratio, as cover crops around ash trees (A). Three psyllids: Psyllopsis repens Loginova, P. securicola Loginova, and P. machinosus Loginova were collected on ash trees. Which, P. repens with a relative abundance of 73.1–80.7% was the main Psyllopsis species on trees. A significant (P ≤ 0.05) reduction in the population of Psyllopsis, the number of leaf-roll galls, and means of bud-cone-like structures per branch were seen in A-C and A-R plots compared with A-O and A-G treatments. The abundance of Psyllopsis predators per branch was higher in A-C plots than in the other three treatments. The greatest values of the Shannon diversity index (H΄ = 1.98 in 2019 and 1.94 in 2020) and the Pielou's evenness index (J' = 0.90 in 2019 and 0.88 in 2020) for Psyllopsis predators were recorded in A-C plots. The highest parasitism rate of Psyllopsis nymphs by Psyllaephagus claripes Trjapitzin, among treatments, was seen in A-C plots, 34.2% in 2019 and 29.4% in 2020. A higher abundance and diversity of enemies in the clover plots was perhaps due to supplying the appropriate habitat resources. Implications for insect conservation: Cultivating clover around ash trees provides proper habitat for natural enemies that attract more beneficial insects in fragmented urban landscapes and support biodiversity and biological control services. [ABSTRACT FROM AUTHOR]

Psyllids (superfamily Psylloidea), also known as jumping plant lice, are a group of plant-sap sucking Hemiptera having significant pest status for crops, forest trees and ornamental plants. Only seven species of psyllids have been recorded in Luxembourg so far. An additional group of seven species has been recorded exclusively, based on the findings of their galls or specific plant deformations; but no mention exists in literature on the actual collection of the inducing insect in Luxembourg. To fill this knowledge gap, field collections were carried out during the years 2019-2020. In addition, samples from 1999-2000 stored in the wet collection of the Musée National d’Histoire Naturelle de Luxembourg were studied. This research, in combination with information coming from literature, allowed us to list 48 species of the families Aphalaridae (5 species), Liviidae (5), Psyllidae (24) and Triozidae (14), though the presence of one species within the last family (Trioza rhamni) needs to be confirmed. Brief information on geographical distribution, biology and (if available) illustrations of diagnostic characters are provided on the psyllid species detected in Luxembourg so far.

Background: Although it is known that Candidatus Liberibacter asiaticus (CLas), the agent of citrus Huanglongbing, circulates and multiplies within the insect vector Diaphorina citri, the specific factors enabling CLas transmission remain unclear. Previous studies have shown that ATPSyn-β facilitates phytoplasma movement in vector insects, and functions as a transport protein in D. citri. In this study, the role of ATPSyn-β was expected to be unveiled in CLas transmission in D. citri., Results: The interaction between ATPSyn-β of D. citri and the outer membrane protein A (OmpA) of CLas was identified using glutathione S-transferase pull-down and yeast two-hybrid assays. No interactions existed between OmpA and vitellogenin (Vg). Bioinformatics analysis revealed that ATPSyn-β contained two conserved domains, ATP-synt_ab_N and ATP-synt_ab. Notably, ATP-synt_ab_N interacted with both OmpA and Vg, indicating a competitive relationship between Vg and OmpA for binding to ATPSyn-β. After silencing ATPSyn-β expression using RNAi, the feeding behavior of D. citri decreased, resulting in a lower acquisition of CLas. Subsequently, this inhibited CLas movement within D. citri and reduced the inoculation of CLas to healthy citrus plants., Conclusion: ATPSyn-β was involved in the acquisition, movement in vivo, and inoculation of CLas by interacting with OmpA, thus offering a novel target to prevent the spread of citrus Huanglongbing. © 2025 Society of Chemical Industry., (© 2025 Society of Chemical Industry.)

Competing Interests: The author(s) declare no conflict of interest.

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).

Mitochondrial genome sequences have been used in diverse fields of biology. In this study, we sequenced the complete mitochondrial genomes (mitogenome) of two pear pests: Cacopsylla jukyungi, the most damaging insect pest to commercial pears in South Korea, and Cacopsylla burckhardti (Hemiptera: Psyllidae). The two mitogenomes were compared to confamilial species to accumulate genetic information and understand evolutionary characteristics of the family Psyllidae. The 15,438 bp-and 14,799 bp-long complete mitogenomes of C. jukyungi and C. burckhardti, respectively, had many features typical of insect mitogenomes; however, at 1283 bp, the C. jukyungi mitogenome had an unusually long A+T-rich region, which was composed of two identical 540-bp repeat sequences. Among the intergenic spacer regions, the one located at the ND1 and trnS2 junction was relatively well conserved in length (mostly within 23–36 bp). This region had a high sequence identity in all Psyllidae, possessing a 5-bp consensus sequence (CGGTA), which is speculated to have a functional role. Though the A+T-rich region in available Psyllidae mitogenomes varied substantially in length (662–1430 bp) and sequence divergence, all species had a conserved sequence stretch at the 3′-end of srRNA, which is also speculated to have a functional role. Genetic divergence among genes indicated the lowest variability in srRNA, lrRNA, and COI, whereas ATP8 and ND6 showed the highest variability at both family and genus (Cacopsylla) levels. Our data provide evidence that the family Psyllidae, including current C. jukyungi and C. burckhardti, have evolutionary unique features that were previously undetected, along with the unique A+T-rich region structure in C. jukyungi. [ABSTRACT FROM AUTHOR]

Psyllids (superfamily Psylloidea), also known as jumping plant lice, are a group of plantsap sucking Hemiptera having significant pest status for crops, forest trees and ornamental plants. Only seven species of psyllids have been recorded in Luxembourg so far. An additional group of seven species has been recorded exclusively, based on the findings of their galls or specific plant deformations; but no mention exists in literature on the actual collection of the inducing insect in Luxembourg. To fill this knowledge gap, field collections were carried out during the years 2019-2020. In addition, samples from 1999-2000 stored in the wet collection of the Musée National d'Histoire Naturelle de Luxembourg were studied. This research, in combination with information coming from literature, allowed us to list 48 species of the families Aphalaridae (5 species), Liviidae (5), Psyllidae (24) and Triozidae (14), though the presence of one species within the last family (Trioza rhamni) needs to be confirmed. Brief information on geographical distribution, biology and (if available) illustrations of diagnostic characters are provided on the psyllid species detected in Luxembourg so far. [ABSTRACT FROM AUTHOR]

An alternative approach for suppressing ACP populations which has not been tried before, is the use of pesticidal proteins that are produced by bacteria. The soil-dwelling bacterium, Bacillus thuringiensis (Bt) produces lots of proteins that are insecticidal against certain types of insects. These proteins allow Bt to enter the insect host, divide inside the body of the insect ultimately killing it. Bt is a valuable natural product for insect control and is widely used to control mosquito larvae residing in pools of water, and in organic agriculture for example. Drawing on the use of Bt pesticidal proteins for management of other insects such as the western corn rootworm in maize and the pink bollworm in cotton, researchers at the University of Florida tested multiple Bt pesticidal proteins for toxicity against ACP. To date, we have also produced citrus seedlings that express the Bt pesticidal protein and verified that these can kill feeding ACP. However, the selected Bt pesticidal proteins showed only moderate killing of ACP and by themselves may not represent a major advancement over the efficacy which could be obtained with insecticides. The next step has been to test the effects of the pesticidal protein in combination with gene silencing RNAs. Gene silencing RNAs are small molecules that reduce or block the expression of ACP genes that are essential for survival of the psyllid. Although our project has met several pre-determined milestones with success in a laboratory setting, we recognize that several challenges must be overcome to deliver a field ready technology to growers who need new tools now. We are therefore frequently sharing our results with industry personnel to receive feedback on how to minimize potential regulatory challenges to acceptance of a field ready product. A field ready tool that combines Bt pesticidal proteins with gene silencing RNAs will not by itself solve the problem of citrus greening. We envision this technology to work in concert with an integrated program that simultaneously focuses on plant health and potentially targets the pathogen itself. However, this novel two-pronged approach for managing psyllids is expected to reduce our reliance on insecticides and increase our capabilities in wiping out psyllids on a large scale.

Candidatus Liberibacter spp. are fastidious α-proteobacteria that cause multiple diseases on plant hosts of economic importance, including the most devastating citrus disease: Huanglongbing (HLB). HLB was reported in Asia a century ago but has since spread worldwide. Understanding the pathogenesis of Candidatus Liberibacter spp. remains challenging as they are yet to be cultured in artificial media and infect the phloem, a sophisticated environment that is difficult to manipulate. Despite those challenges, tremendous progress has been made on Ca. Liberibacter pathosystems. Here, we first reviewed recent studies on genetic information of flagellar and type IV pili biosynthesis, their expression profiles, and movement of Ca. Liberibacter spp. inside the plant and insect hosts. Next, we reviewed the transcriptomic, proteomic, and metabolomic studies of susceptible and tolerant plant genotypes to Ca. Liberibacter spp. infection and how Ca. Liberibacter spp. adapt in plants. Analyses of the interactions between plants and Ca. Liberibacter spp. imply the involvement of immune response in the Ca. Liberibacter pathosystems. Lastly, we reviewed how Ca. Liberibacter spp. movement inside and interactions with plants lead to symptom development. [ABSTRACT FROM AUTHOR]

BACKGROUND Economic injury level (EIL) and economic threshold (ET) are customary tools for integrated pest management. Cacopsylla pyri L. is a major pest in pear orchards. The aim of this work was to establish EIL and ET for the optimization of the use of insecticides to control this psyllid, considering biocontrol and two spraying strategies (low‐toxicity versus broad spectrum chemicals). This research was conducted over 4 years in five commercial pear, cv. Ercolini, orchards in south‐eastern Spain. RESULTS: Psyllids and ant populations were followed using periodic sampling, and the russet on fruits was quantified. The effect of spray intensity and ant exclusion on psyllid abundance and yield were also tested: both had a significant effect on the cumulative number of C. pyri (CNP), yield and fruit weight. Yield was found to be negatively correlated with CNP. The russet index (RI) increased in a sigmoidal fashion as a function of CNP, being significantly higher with than without ant exclusion. The commercial categorization of fruits was explained satisfactorily as a function of CNP and the cumulative number of ants (CNA). The quantitative EIL was established at a CNP of 427.2 for spraying with paraffinic oil and 425.7 for abamectin. As for the cosmetic EIL, when CNA was zero, this EIL was 24.2, at a CNP of 16.6 for spraying with paraffinic oil or abamectin. CONCLUSIONS: The use of products of low toxicity, for the conservation of ants, is expected to increase ET and, thus, reduce the intensity of spraying. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is an important food crop worldwide. As the demand for fresh and processed potato products is increasing globally, there is a need to manage and control devastating diseases such as zebra chip (ZC). ZC disease causes major yield losses in many potato-growing regions and is associated with the fastidious, phloem-limited bacterium Candidatus Liberibacter solanacearum (CLso) that is vectored by the potato-tomato psyllid (Bactericera cockerelli Šulc). Current management measures for ZC disease mainly focus on chemical control and integrated pest management strategies of the psyllid vector to limit the spread of CLso, however, they add to the costs of potato production. Identification and deployment of CLso and/or the psyllid resistant cultivars, in combination with integrated pest management, may provide a sustainable long-term strategy to control ZC. In this review, we provide a brief overview of the ZC disease, epidemiology, current management strategies, and potential new approaches to manage ZC disease in the future.

Potato (Solanum tuberosum L.) is an important food crop worldwide. As the demand for fresh and processed potato products is increasing globally, there is a need to manage and control devastating diseases such as zebra chip (ZC). ZC disease causes major yield losses in many potato-growing regions and is associated with the fastidious, phloem-limited bacterium Candidatus Liberibacter solanacearum (C Lso) that is vectored by the potato-tomato psyllid (Bactericera cockerelli Šulc). Current management measures for ZC disease mainly focus on chemical control and integrated pest management strategies of the psyllid vector to limit the spread of C Lso, however, they add to the costs of potato production. Identification and deployment of C Lso and/or the psyllid resistant cultivars, in combination with integrated pest management, may provide a sustainable long-term strategy to control ZC. In this review, we provide a brief overview of the ZC disease, epidemiology, current management strategies, and potential new approaches to manage ZC disease in the future. [ABSTRACT FROM AUTHOR]

This paper opens the themed issue (a monograph) "Aberrant cytogenetic and reproductive patterns in the evolution of Paraneoptera", prepared by a Russian-Bulgarian research team on the basis of long-term collaborative studies. In this first part of the issue, we provide the basic introductory information, describe the material involved and the methods applied, and give terminology and nomenclature of used taxonomic names. [ABSTRACT FROM AUTHOR]

In the framework of a survey of arthropods in rest stops of Hungarian highways, 19 species of jumping plant lice were collected. Three species belong to the family Aphalaridae, one to Calophyidae, two to Liviidae, nine to Psyllidae and four to Triozidae. Two species (Livilla variegata and Trioza neglecta) are alien, non-indigenous species; the others are native to Hungary. The most abundant species were Calophya rhois, Cacopsylla melanoneura and Trioza neglecta. The specimens of C. melanoneura were found in 20, T. neglecta in 10 and C. rhois in 6 localities out of the 31 rest stops surveyed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Modern pest control management systems are based on the support of naturally occurring arthropod predators, as it has been shown that such predators offer an important ecosystem service. However, most naturally occurring arthropod predators are generalists (euryphagous). Their role in the biological control of specific pests has been recognized but remains poorly studied. Here, we focused on the naturally occurring arthropod predators of psyllids – the main insect pest of pear trees. We investigated the abundance of psyllids and all of their potential enemies in an abandoned pear orchard on a weekly basis from early spring to early summer. In addition, employing polymerase chain reaction diagnostics and specific primers, we investigated the predation rate on psyllids in all predators collected. RESULTS: We found four predatory groups: spiders were the most abundant (60%, N = 756), followed by coccinellid beetles, anthocorid bugs and cantharid beetles. Anthocorids and spiders had the highest predation rates among the predatory groups. Among spiders, >50% of foliage‐dwelling spiders (belonging to the genera Philodromus and Clubiona; N = 206) were positive for psyllids and showed a numerical response to the abundance of psyllids. CONCLUSION: We conclude that foliage‐dwelling spiders are, of the four groups, the most important natural enemies of psyllids on pear trees during spring in Central Europe, as they outnumber specialized Anthocoris bugs. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The purpose of this application, under Article 23.9.3 of the Code, is to conserve the usage of the generic name CtenarytainaFerris & Klyver, 1932 for a genus of psyllids (Insecta, Hemiptera) from tropical and subtropical regions around the world. This name, which has been used in hundreds of works in recent decades, is threatened by a purported senior synonym, EurhinocolaCrawford, 1912. This genus was erected for Eurhinocola gravelyiCrawford, 1912 from Myanmar, a species that has not been mentioned since then in the literature except in catalogues. In 2020 the two genera were formally synonymized. Besides those already mentioned, only three other substantial publications on Eurhinocola have appeared, all between 1924 and 1937 and all pertaining to Eurhinocola eucalypti (Maskell, 1890). Using the senior synonym Eurhinocola would lead to nomenclatural instability and confusion, particularly with respect to two economically important species that are classified now in Ctenarytaina. We therefore request a reversal of precedence under the Commission's plenary power, with Ctenarytaina to be given precedence over Eurhinocola whenever the two are considered to be synonyms. [ABSTRACT FROM AUTHOR]

Several studies have documented the positive effects of controlling the Asian citrus psyllid (ACP, Figure 1) for citrus tree health and sustainability in Florida. The mature blocks established before and after the discovery of huanglongbing (HLB) in 2005 continue to benefit from psyllid control. Peer reviewed through UF/IFAS Citrus Research and Education Center; published in Citrus Industry Magazine

Jumping plant-lice (Hemiptera, Sternorrhyncha, Psylloidea) are small phloemfeeding insects. With about 400 species distributed in Europe, the European fauna is considered well-studied. However, information on psyllids occurring in the eastern Balkan Peninsula is insufficient. So far, less than a hundred psyllid species are known for Bulgaria, most of which have been reported only from a few regions. Knowledge on the psyllid fauna of the Sarnena Sredna Gora Mountains in central Bulgaria is sparse and relatively old, with only a handful of recorded species. The aim of the present study is to summarise the information on Psylloidea from this region, including recently collected material kept in the zoological collection of Sofia University. A total of 17 species were found of which 7 species had been previously published and 10 species from 3 families are new to the region: Aphalara freji Burckhardt & Lauterer, 1997 (Aphalaridae), Diaphorina lycii Loginova, 1978, Arytaina maculata (Löw, 1886), Cacopsylla bidens (Šulc, 1907), Cacopsylla melanoneura (Foerster, 1848), Cacopsylla pulchra (Zetterstedt, 1838), Livilla horvathi (Scott, 1879), Psylla foersteri Flor, 1861 (all Psyllidae), Bactericera modesta (Foerster, 1848) and Trioza rotundata Flor, 1861 (Triozidae). [ABSTRACT FROM AUTHOR]

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The Neotropical species of the predominantly north temperate genus Aphalara are reviewed. Four species are recorded here from this region, two of which are described as new. Aphalara ritteri sp. nov. occurs in southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina) and represents the first and only species reported from South America. A second new species, Aphalara ortegae sp. nov., is described from Mexico and Puerto Rico. Another two species, Aphalara persicaria Caldwell, 1937 and A. simila Caldwell, 1937, have been previously reported from Mexico and the USA, and one of them also from Cuba. The two new species are both associated with Persicaria hydropiperoides and P. punctata (Polygonaceae) on which the immatures induce leaf roll galls. The two new species are morphologically similar to A. persicaria, to which they are probably closely related. A key is provided for the adults and immatures of the Neotropical species of Aphalara. [ABSTRACT FROM AUTHOR]

Huanglongbing (HLB) is one of the most catastrophic citrus diseases. HLB pathogens Candidatus Liberibacter asiaticus (Las), Ca. L. africanus (Laf), and Ca. L. americanus (Lam) and their insect vectors Asian citrus psyllids (ACP, Diaphorina citri) and African citrus psyllids (AfCP, Trioza erytreae) are invading citrus producing regions where HLB was absent previously, including the Mediterranean basin. Importantly, the Mediterranean region is one of the two major citrus producing areas without HLB. Here, I provide a short perspective regarding a) information related to the distribution of the HLB pathogens and psyllid vectors in this region and neighboring countries, b) predicted distribution of the HLB for this region, c) the possible evolution of Liberibacters and how they could have established their relationship with different hosts, and d) approaches to fend off HLB. Specifically, I emphasized the following measurements: quarantine measures against AfCP, ACP, Las, Laf, and Lam, early detection and diagnosis of HLB and removal of inoculum, surveillance of AfCP and ACP and eradication of citrus psyllids once identified. [ABSTRACT FROM AUTHOR]

Cacopsylla picta (Förster, 1848) (Hemiptera: Pysllidae) is the main vector of apple proliferation, a phytoplasma-caused disease. It represents one of the most severe problems in apple orchards, and therefore, there is a mandatory requirement to chemically treat against this pest in the European Union. Sexual communication using substrate-borne vibrations was demonstrated in several psyllid species. Here, we report the characteristics of the vibrational signals emitted by C. picta during courtship behavior. The pair formation process can be divided into two main phases: identification and courtship. Females initiate the communication on the host plant by emitting trains of vibrational pulses and, during courtship, if males reply, by emitting a signal consisting of a series of pre-pulses and a 'buzz', a duet is established. Moreover, a scanning electron microscopy investigation showed the presence of a stridulatory structure on the thorax and wings of both sexes, whereas the video recordings elucidated associated wing movement. The results provide new information about the biology of this phytoplasma vector and could form a basis of an environmentally friendly pest management strategy. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ants are known to establish antagonistic and mutualistic interactions with honeydew‐producing hemipterans, depending on the species involved and the ecological context. The aim of this work was to infer the role that such interactions play in the population dynamics of psyllids and aphids in pear orchards. Interactions were inferred from field data and periodical sampling along a 4‐year study, and from interaction assays performed under controlled conditions. RESULTS: A decline in the abundance of the pear psyllid (Cacopsylla pyri L.), parallel to an increase in the abundance of aphids, was registered over 4 years. Ants were the dominant species, representing about 90% of the predators, followed by spiders and predatory hemipterans (namely Pilophorus gallicus Remane). Ant abundance increased over the 4 years, matching the population dynamics of aphids. Evidence of mutualistic and antagonistic interactions were found for ant–aphid and ant–psyllid, respectively: (i) ant–aphid abundances on pear trees were positively correlated, and ants reduced predation on aphids by generalist predators, and (ii) ant–psyllid abundances were negatively correlated, ants have a negative effect on the psyllid population growth rates, and ants were found to prey on the psyllid. CONCLUSIONS: Because of their high abundance in comparison with other predators and the mutualistic–antagonistic relationships with aphids–psyllids, ants are considered to be the principal force behind the decline of pear psyllid populations and the increase in aphid numbers. In summary, ants contribute positively to biological control by the suppresion of pests (i.e. the psyllid) which are more damaging than those they protect (i.e. aphids). © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Background: With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids. Results: We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII)-tRNA(gly)-NADH dehydrogenase subunit 3(ND3)- tRNA(ala)- tRNA(arg)- tRNA(asn) from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types. Conclusions: In whiteflies, the region of the mitochondrial genome consisting of genes encoding for COIII-tRNA(gly)- ND3-tRNA(ala)- tRNA(arg)- tRNA(asn) can be transposed from its ancestral position to four different locations on the mitochondrial genome. Related species within clusters established by phylogenetic analysis of host and endosymbiont genes have the same mitochondrial gene arrangement indicating a transposition in the ancestor of these clusters.

Abstract Background Transcriptomic analyses were performed to compare the molecular responses of two potato varieties previously shown to differ in the severity of disease symptoms due to infection by “Candidatus Liberibacter solanacearum” (Lso), the causative agent of Zebra Chip in potato. A factorial design utilizing the two varieties and psyllids either harboring Lso or without bacteria was used to discriminate varietal responses to pathogen infection versus psyllid feeding. Plant response was determined from leaf samples 3 weeks after infection. Results In response to Lso infection, 397 genes were differentially expressed in the variety Atlantic (most susceptible) as compared to 1027 genes in Waneta. Over 80% of the transcriptionally-changed genes were down-regulated in both varieties, including genes involved in photosynthesis or primary and secondary metabolism. Many of the Lso-responsive genes involved in stress responses or hormonal pathways were regulated differently in the two potato varieties. Conclusions This study focused on the time point just prior to the onset of symptom development and provides valuable insight into the mechanisms of Liberibacter pathogenicity, especially the widespread suppression of plant gene expression, including genes involved in plant defenses.

Weed management is a crucial component in Florida’s citrus production. Recent research from our group shows that weed management may have pest management benefits for citrus growers in addition to traditionally known horticultural gains. Maintaining a ‘weed-free’ grove and perimeter areas can potentially help improve the management of the Asian citrus psyllid (ACP), the insect vector that spreads pathogens causing HLB.