Explore the vast range of titles available.

Gall formation impacts the development of plant species by altering the structure and mobilization of reserves, and the functional and physiological patterns of the host organ. The current study aimed to evaluate the impact generated by the Neolithus fasciatus galling insect (Hemiptera: Triozidae) in Sapium glandulosum leaves (Euphorbiaceae) at the cytological, histological, histochemical, and biochemical levels. Non-galled leaves and galls in the young, mature, and senescent stages were evaluated. The non-galled leaf has a uniseriate epidermis, stomata only on the abaxial side, a dorsiventral mesophyll, and parenchyma cells with thin primary walls containing chloroplasts with plastoglobules. The gall has a parenchymatous compartmentalized cortex. The young and mature galls already have a dense cytoplasm, especially in the inner cells of the cortex, with chloroplasts, mitochondria, Golgi complex, and large and evident nuclei. In senescent galls, there are signs of organelle degradation and cell digestion. Carbohydrates occur in greater amounts in the mature gall, mainly in the starch grain form, while proteins and lipids predominate in non-galled leaves. Secondary metabolites occur mainly in the young gall and may be related to its protection and to the signaling of its development. Sapium glandulosum galls have histological and cytological compartmentalization of the cortex with a large amount of carbohydrates, which supply energy to maintain the development of the structure.

Background The Hawaiian Pariaconus psyllid radiation represents a unique system to study the co-evolution of nuclear, mitochondrial, and endosymbiont genomes. These psyllids, which diversified across the Hawaiian Islands during the last 3–3.5 million years vary with their ecological niches on their plant host ‘Ōhi’a lehua ( Metrosideros polymorpha ) (free-living, open-gall, and closed-gall lifestyles) and harbor one to three beneficial bacterial endosymbionts. Co-evolutionary studies of other multi-endosymbiont insect systems have shown decoupled rates of sequence evolution between mitochondria and endosymbionts. Here we examine the evolutionary trends in Pariaconus psyllids, their mitochondria and their endosymbionts to determine if they fit this paradigm. Results We sequenced a new Carsonella genome from the ohialoha species group (closed-gall, one symbiont), revealing a remarkable degree of gene conservation between two of the most divergent species from this diverse species group that has dispersed across multiple islands. Further, despite the rapid radiation of psyllid species, we observed complete synteny among mitochondrial genomes from all six Pariaconus species in this study, suggesting the preservation of genome structure due to strong purifying selection. Phylogenetic analyses of the nuclear, mitochondrial, and endosymbiont genomes across these six Pariaconus species revealed correlated rates of substitutions, contrary to prior reports of decoupling between mitochondrial and endosymbiont genomes in other insect systems with multiple symbiont partners. Finally, we found that free-living psyllids with three symbionts exhibited elevated mutation rates (~ 1.2–1.6x) across all genomes and elevated rates of fixation of nonsynonymous substitutions in the insect nuclear genome and one of the endosymbionts. Conclusions This study highlights the interplay between ecological diversification and genomic evolution in Pariaconus . Further, these data indicate that multiple endosymbiont partners alone are not sufficient to result in decoupling rates of sequence evolution. Future work on basal members of this species radiation will refine our understanding of the mechanisms shaping this dynamic insect-symbiont system and its implications for genome evolution.

The use of nanoparticles (NPs) has generated an alternative pest control. The objective was to evaluate the insecticidal effect of zinc oxide nanoparticles (ZnO NPs), titanium dioxide nanoparticles (TiO2 NPs), and their combination on Bactericera cockerelli (Hemiptera: Triozidae) second-stage nymphs under laboratory and greenhouse conditions in tomato. The laboratory research was carried out with the leaf immersion bioassay method under a complete randomized design, and in the greenhouse by direct plant spraying under a randomized block design; in both designs, a control without NPs was added. Mortality was recorded every 24 h for 4 days. Both NPs in the laboratory and greenhouse showed toxicity to B. cockerelli nymphs. Results in the laboratory showed that NPs significantly caused increased mortality of 88, 99, and 100% 96 h after treatment of ZnO NPs, TiO2 NPs, and their combinations, at 1000, 100, and 250 ppm, respectively. Direct spray of plants in the greenhouse showed low mortality with 27, 32, and 23% after 96 h of ZnO NPs, TiO2 NPs, and their combinations, at 3000, 500, and 250 ppm, respectively. These results on B. cockerelli control seem promising. Nanoparticles as insecticides are a novel strategy, however, further investigation is required in field tests to obtain suitable efficacy for use in a pest management system.

In recent years, an increase in baseline arthropod surveys and closer scrutiny of specimens from current and past collections have resulted in a rise of adventive psyllid species discoveries in the Hawaiian Islands. In some cases, the new records reported here may have been known for some time but not officially published in the literature. In other cases, specimens remained unidentified for several years. We provide an updated checklist of the 23 adventive psyllid species in the Hawaiian Islands, including six new state records, and at least one new island record. The majority of recent psyllid establishment records, including those newly reported here, are in the subfamily Spondyliaspidinae (Aphalaridae). These records are overwhelmingly Australasian in origin, with host plant associations in the family Myrtaceae, predominantly Eucalyptus . One of these new Australasian-origin records, Australopsylla exotica Matsunaga & Percy, sp. nov ., is described here as a new species from adults and immatures. A molecular systematic overview of the phylogenetic placement of native and adventive taxa includes an analysis of the position of A. exotica within Australopsylla .

The potato psyllid, Bactericera cockerelli (Šulc), is a major pest of potato (Solanum tuberosum L.; Solanales: Solanaceae) as a vector of ‘Candidatus Liberibacter solanacearum’, the pathogen that causes zebra chip. Management of zebra chip is challenging in part because the noncrop sources of Liberibacter-infected psyllids arriving in potato remain unknown. Adding to this challenge is the occurrence of distinct genetic haplotypes of both potato psyllid and Liberibacter that differ in host range. Longleaf groundcherry (Physalis longifolia Nutt.) has been substantially overlooked in prior research as a potential noncrop source of Liberibacter-infected B. cockerelli colonizing fields of potato. The objective of this study was to assess the suitability of P. longifolia to the three common haplotypes of B. cockerelli (central, western, and northwestern haplotypes), and to two haplotypes of ‘Ca. L. solanacearum' (Liberibacter A and B haplotypes). Greenhouse bioassays indicated that B. cockerelli of all three haplotypes produced more offspring on P. longifolia than on potato and preferred P. longifolia over potato during settling and egg-laying activities. Greenhouse and field trials showed that P. longifolia was also highly susceptible to Liberibacter. Additionally, we discovered that infected rhizomes survived winter and produced infected plants in late spring that could then be available for psyllid colonization and pathogen acquisition. Results show that P. longifolia is susceptible to both B. cockerelli and ‘Ca. L. solanacearum’ and must be considered as a potentially important source of infective B. cockerelli colonizing potato fields in the western United States.

Fifteen species of Psyllaephagus from China are studied. Three species, P. clavus Zou & Zhang, sp. nov. , P. obliquus Zou & Zhang, sp. nov. , and P. tangae Zou & Zhang, sp. nov. , are described as new to science. A diagnosis or a description/redescription, figures of the characters, as well as the known distribution and hosts of each species are provided. A dichotomous key is also given to facilitate the identification of species.

A nettle-feeding psyllid of the genus (Hemiptera: Triozidae) was discovered in Hokkaido, northern Japan. Although the European species has been reported from Japan in several databases and publications, these records are based on erroneous literature citations rather than examined specimens. Adult and immature materials collected from were examined morphologically and analysed using mitochondrial cytochrome oxidase subunit I (COI) DNA barcoding. The Japanese species is closely related to Palaearctic and Nearctic but is consistently distinguishable by several adult and immature morphological characters. In addition, COI sequences show large interspecific divergence (≥12%) among the three species, supporting its distinct taxonomic status. The Japanese species is therefore described as sp. nov., and Japan is formally excluded from the distribution range of . These results indicate that records of in East Asia surrounding Japan require re-examination using both morphology and DNA barcoding. A diagnostic key to all known -feeding species of worldwide is provided. Furthermore, the Chinese species Li, 2011 is transferred to as (Li, 2011) comb. nov.

The release of Tamarixia triozae (Burks) (Hymenoptera: Eulophidae), a parasitoid of the potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) , resulted in the successful establishment of the parasitoid in New Zealand. The parasitoid was released at more than 30 sites by the final year of the three-year study throughout New Zealand. Its continued presence over the three-year study was confirmed in two regions (Hawke’s Bay and Canterbury). At one site in Canterbury, the parasitoid was released only in the first summer of this study (Nov. 2017–Feb. 2018). It was recovered from potato psyllid infested African boxthorn ( Lycium ferocissimum Miers) foliage in the second and third summers at this site, demonstrating the parasitoid’s ability to survive over successive winters. We found T. triozae parasitized nymphs at 24 sites of the 86 potato psyllid host plant sites surveyed within a 25 km radius of known release sites in Hawke’s Bay. The parasitoid was found up to 24 km from the nearest known release site in Hawke’s Bay. In Canterbury, the parasitoid was found up to 0.6 km from a known release site. Parasitism rates of 13.7–15.6% were estimated based on two post-release survey methods employed in this study. The parasitoid also feeds on psyllid nymphs so its establishment may lead to helping to reduce or delay potato psyllid populations from reaching damaging levels. Long-term monitoring is needed to determine the consequences of importing T. triozae on populations of potato psyllid.

Nitrogen fertilization plays a critical role in the growth and productivity of potato crops, yet its impact on pest populations, particularly Myzus persicae and Bactericera cockerelli , remains underexplored. This study investigates the effects of different nitrogen sources and dosages on the population dynamics of these pests in potato cultivation. Conducted in a greenhouse, the experiment involved three nitrogen sources—ammonium nitrate, calcium nitrate, and ammonium sulfate—applied at three dosages (0.5X, 1X, and 2X). Results indicate that nitrogen fertilization significantly influences M. persicae populations, with intermediate nitrogen levels increasing aphid density and higher levels reducing it. Ammonium nitrate and calcium nitrate particularly favored aphid proliferation. In contrast, B. cockerelli populations exhibited marginal responses to nitrogen fertilization, suggesting different nutritional preferences and interactions. This study highlights the need for balanced nitrogen management in pest control strategies, advocating for integrated approaches that consider fertilizer type and application levels to mitigate pest issues while sustaining crop yields. These findings provide valuable insights for optimizing nutrient management in potato agriculture and enhancing pest control measures.

The tomato potato psyllid Bactericera cockerelli (Sulcer) (Hemiptera: Triozidae) is a serious pest of several solanaceous crops in different parts of the world. We examined the biological control potential of the zoophytophagous bug Engytatus varians (Distant) (Hemiptera: Miridae), in combination with the ectoparasitoid Tamarixia triozae (Burks) (Hymenoptera: Eulophidae) on B. cockerelli -infested pepper ( Capsicum annuum L.) plants in cages under greenhouse conditions. A single release rate (one adult per plant) of either E. varians or T. triozae was used and the timing of predator releases varied (before or after pest establishment). The number of nymphs and adults of B. cockerelli or the number of mirids (nymphs plus adults) and parasitoids (pupae plus adults) was determined three or four weeks after release. Both E. varians and T. triozae successfully established on pepper plants and significantly reduced the pest population density (by 91 to 96% and by 84 to 100% of nymphs and adults, respectively) when they were released separately or in combination, even when the predator was released before the establishment of B. cockerelli . At the end of the experiment, the density of E. varians was between one and two individuals per leaf, whereas that of the parasitoid was between one and six individuals per leaf in the treatments in which each natural enemy was released. These results could contribute to the integrated pest management of B. cockerelli . However, further studies are needed to validate the impact of both natural enemies on the control of this pest at a larger scale.