New species of Acizzia Heslop-Harrison (Hemiptera: Psyllidae) from Australian mistletoe (Loranthaceae)

Three new species of Acizzia are described from Australian mistletoe (Loranthaceae: Amyema spp.). These are: A. loranthacae sp. n., A. amyemae sp. n. and A. pendulae sp. n. They are characterised by: male proctiger with prominent posterior lobe; antenna 1.9–2.9 times width of head; forewing with costal break and pterostigma, with pattern in A. amyemae and A. pendulae but not in A. loranthacae ; and female proctiger simple in A. amyemae and A. pendulae but with prominent dorso-apical process in A. loranthacae . The Loranthaceae is a new host family record for Acizzia . Given the probable radiation of Acizzia on mimosaceous hosts, its occurrence on eucalypt-inhabiting mistletoe, yet its apparent absence from mistletoes on Acacia, is discussed.     

Characterization of microsatellite loci in Cacopsylla melanoneura Förster (Homoptera: Psyllidae)

Cacopsylla melanoneura is one of the main vectors of ‘Candidatus Phytoplasma mali’. We developed and described 10 microsatellite markers. Forty‐five psyllids from one population were analysed. The number of alleles ranged from six to 24 and the observed heterozygosity from 0.42 to 0.84. These markers will be useful tools for population genetic studies on C. melanoneura.     

First record of the mulberry psyllid Anomoneura mori Schwarz (Hemiptera: Psylloidea: Psyllidae) from Taiwan

The mulberry psyllid Anomoneura mori Schwarz is reported for the first time from Taiwan. This species is associated with the mulberry tree and is a pest of sericulture. Adults and larvae are described and illustrated for identification. The topic of invasive species is further discussed.     

Effects of the fungus Isaria fumosorosea (Hypocreales: Cordycipitaceae) on reduced feeding and mortality of the Asian citrus psyllid,Diaphorina citri (Hemiptera: Psyllidae)

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is an important citrus pest primarily because it transmits bacteria putatively responsible for huanglongbing, a serious disease of citrus. We present a study on the effects of blastospore and conidial formulations of Isaria fumosorosea Wize on feeding rates and mortality of adult psyllids in laboratory bioassays. Information on quantities of honeydew droplets was used to make inferences on feeding rates. Psyllids treated with the blastospore formulation of I. fumosorosea produced fewer honeydew droplets compared to the conidial treatment and control beginning within the first 24 h after treatment. The highest daily mean number of droplets thereafter never exceeded 2.4 drops compared to 4 and 8 for the conidial treatment and control, respectively. The mean number (±SEM) of honeydew droplets produced per psyllid per day over 7 days was significantly higher in the control (5.5±0.5) compared to the blastospore treatment; however, there were no significant differences between the treatments. Psyllids treated with the conidial formulation of the pathogen showed no significant reduction in feeding activity until 4 days after treatment. One and 2 day's post-exposure, mortality of psyllids in the blastospore treatment ranged from 8 to 25% compared to 0% in the conidial and control treatments. By 7 days post-exposure, psyllid mortality reached 100% under both fungal treatments compared to none in the controls. This study documented that adult psyllids infected by I. fumosorosea (PFR 97) produce less honeydew than healthy psyllids and suggests that they may feed less, which could potentially reduce the spread of huanglongbing.     

Morphological description of the mouthparts of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae)

Scanning (SEM) and transmission (TEM) electron microscopy were used to elucidate the morphology of the rostrum, as well as the mandibular and maxillary stylets of the psyllid Diaphorina citri, vector of phloem-inhabiting bacteria associated with citrus huanglongbing (HLB) disease. D. citri has a cone-shaped rostrum that extends behind the pair of prothoracic coxae. The stylet bundle comprises a pair of mandibular (Md) and maxillary (Mx) stylets with a mean length of 513.3 μm; when retracted, their proximal portions form a loop and are stored in the crumena (Cr). Serial cross-sections of the rostrum revealed that the mandibles are always projected in front of the maxillary stylets. The two maxillary stylets form the food and salivary canals, with diameters of 0.9 μm and 0.4 μm respectively. These two canals merge at the end of the stylets forming a common duct with a length of 4.3 μm and a mean diameter of 0.9 μm. The acrostyle, a distinct anatomical structure present in the common duct of aphid maxillary stylets, was not observed by TEM in the ultrathin cross-sections of the common duct (CD) of D. citri. This study provides new information on D. citri mouthparts that may help to understand the feeding behaviour of this important vector of HLB-associated bacteria.     

Seasonal variation in susceptibility of the pear psyllid,Cacopsylla permixta (Hemiptera: Psyllidae) to selected insecticides

Although Cacopsylla pyri Forster and Cacopsylla pyricola Linnaeus have long been considered as more significant pests of pear trees around the world, Cacopsylla permixta Burckhardt and Hodkinson is the most significant pest in some parts of Iran, especially in pear gardens of Karaj. Current control strategies against this pest in Iran generally involve five or six insecticide treatments each year, despite unsatisfactory results are reported at many localities. So, it is crucial to know the most susceptible generation of the pest to apply a good strategy for its control. The aim of this study was to explore the seasonal variation in susceptibility of C. permixta to four commonly used insecticides. The results showed that winter forms (February) were 2.71‐fold, 4.58‐fold, 3.26 fold and 3.38‐fold more tolerant to diazinon, imidacloprid, acetamiprid and abamectin, respectively, compared with summer forms. Also, Esterase, GST and P450 monooxygenase activity was highest during February. Moreover, the content of lipid, carbohydrate, glycogen and protein was significantly higher in February compared with other months. Based on these results, the best period for insecticide treatment for efficient control is treatment against the first generation, at the time when eggs are laid by females as well as during the egg hatching and the larvae appearance. At this time of year, psylla are more susceptible, which would likely lead to better results and the reduction in damage during the next summer. However, further studies are needed to test this in farm settings, and to whether this holds true for other psylla species.     

柑橘木虱蜜露排泄机制:进展与展望

半翅目昆虫柑橘木虱Diaphorina citri是柑橘类果树重要害虫,主要以高渗透压的植物韧皮部汁液为食,是柑橘毁灭性病害——柑橘黄龙病(HLB)的主要传播媒介。柑橘木虱取食韧皮部汁液时自身进化出一套完整的渗透调节机制调节其体内渗透压,将体内过量摄入的糖类转化成长链寡糖并以蜜露形式排出体外。本文从柑橘木虱蜜露排泄行为、蜜露组成成分以及影响蜜露排泄的多个因素进行了论述,同时综述了可能参与柑橘木虱蜜露排泄行为的渗透调节基因。研究表明,柑橘木虱雌雄成虫及若虫在蜜露排泄行为上存在显著差异,且排泄的蜜露在颜色、纹路及组成成分方面均有不同;寄主植物、杀虫剂、病原微生物及天敌化合物均会影响柑橘木虱蜜露排泄行为。分子机制探究发现,α-葡萄糖苷水解酶、水通道蛋白及糖基转移酶基因等关键渗透调节基因可能参与调控柑橘木虱蜜露排泄行为。本文可为未来有关柑橘木虱蜜露排泄行为方面的研究以及为研制柑橘木虱防治新型药剂开发新靶标提供参考。     

Evaluation of Isaria fumosorosea (Hypocreales: Cordycipitaceae) for control of the Asian citrus psyllid,Diaphorina citri (Hemiptera: Psyllidae)

A laboratory bioassay was developed to evaluate strains of Isaria fumosorosea Wize, against Diaphorina citri. Up to 100% of adult psyllids were killed at concentrations between 10⁶ and 10⁷ blastospores/ml after 12 days, with derived LC₅₀ values (at 7 days post treatment) between 1.4 × 10⁵ and 2.0 × 10⁶ blastospores/ml for strains ARSEF 3581, FE 9901 and Apopka-97. A significantly higher value (1.5 × 10⁷) was obtained with a conidial formulation of Apopka-97. Average survival times were dosage dependent, i.e. between 10.2 days at 10³ blastospores/ml and 3.5 days at 10⁸ blastospores/ml. Rates of mycosis were also dosage dependent, with up to 100% sporulation on cadavers at 10⁸ blastospores/ml but declining at lower concentrations. The Apopka-97 strain (commercially available as PFR-97) was tested against established D. citri infestations in potted citrus in greenhouse cages. Treatments at label rates reduced psyllid populations by approximately 50% over 3 weeks. The combination of PFR-97 with emulsifiable oils (0.25% v/v) did not increase psyllid mortality compared with either agent alone. Imidacloprid applied as a drench killed 100% of psyllids within 3 weeks. Subsequent greenhouse tests during humid conditions were hampered by natural dissemination of I. fumosorosea to untreated psyllids, suggesting that this fungus is spread by air movement and may be highly effective under very humid conditions. In later tests, a Cladosporium sp. rapidly colonised psyllid cadavers and leaf surfaces, but was not pathogenic in laboratory tests. Our studies confirm the potential of I. fumosorosea to be used in IPM strategies for D. citri that rely on other tactics, such as insecticidal oils and native or introduced biological control agents.     

The role of psyllids (Hemiptera: Psyllidae) and bell miners (Manorina melanophrys) in canopy dieback of Sydney blue gum (Eucalyptus saligna Sm.)

Abstract The presence of the aggressive, colony-forming honeyeater, Manorina melanophrys (bell miner), in the canopies of unhealthy eucalypts has been well reported. There is, however, some debate as to the actual mechanisms producing these unhealthy trees. To investigate further some of the processes that may be contributing to this form of canopy dieback, two field trials were carried out in Olney State Forest, near Wyong, New South Wales. The study site contained Eucalyptus saligna (Sydney blue gum) with canopy dieback and was occupied by a large colony of bell miners. Close examination of the foliage revealed a large and diverse suite of phytophagous insects, including at least 16 species of psyllid (Hemiptera: Psyllidae). In the first trial, the use of bird exclusion cages over selected branches significantly improved leaf survival compared to leaves exposed to a relatively high density of bell miners. It is proposed that colonization by bell miners may interfere with the efficacy of both other insectivorous birds (through aggressive interspecific territoriality) and the invertebrate predators and parasitoids. Interference with such regulatory factors may enable some phytophagous insect populations to rise to sustained damaging levels. In the second trial, an insecticide application combined with reduced competition from the dense understorey and neighbouring trees was required to significantly improve trunk diameter and crown condition scores. After 12 months, neither treatment, by itself, significantly improved both growth measures. Possibly both treatments were required because the E. saligna trees were suffering from another source of stress (e.g. drought) in addition to the relatively high level of insect attack.     

Fine structure and sensory apparatus of the mouthparts of the pear psyllid,Cacopsylla chinensis (Yang et Li) (Hemiptera: Psyllidae)

The pear psyllid, Cacopsylla chinensis (Yang et Li) (Hemiptera: Psyllidae), is one of the most significant economic pests of pear in China, causing direct damage through feeding by the highly specialized piercing–sucking mouthparts. The ultrastructural morphology and sensory apparatus of the mouthparts of the adult were examined using scanning and transmission electron microscopy. The piercing–sucking mouthparts of C. chinensis are composed of a three-segmented labium with a deep groove in the anterior side, a stylet fascicle consisting of two mandibular and two maxillary stylets, and a pyramid-shaped labrum. Proximal to the labium, the stylet fascicle forms a large loop within a membranous crumena. Mandibles, with more than ten teeth on the external convex region, can be seen on the distal extremity. Smooth maxillary stylets are interlocked to form a larger food canal and a smaller salivary canal. One dendritic canal housing 2 dendrites is also found in each mandible. Two types of sensilla trichodea, four types of sensilla basiconica, single as well as groups of sensilla campaniformia, and oval flattened sensilla occur in different locations on the labium, whereas a kind of sensilla basiconica is at the junction of the labrum and anteclypeus. Sensilla trichodea and sensilla campaniformia, always present with denticles, are present on the middle labial segment. Three types of sensilla basiconica, two types of sensilla trichodea and two oval flattened sensilla are located on the distal labial segment. The mouthpart morphology and abundance of sensilla located on the labium in C. chinensis are illustrated, along with a brief discussion of their taxonomic and putative functional significance.     

Development of simple sequence repeat markers for the Japanese population of the Asian citrus psyllid,Diaphorina citri (Hemiptera: Psyllidae)

We developed nine simple sequence repeat (SSR) markers for the Japanese population of Diaphorina citri Kuwayama, which is known as the vector for citrus greening disease or huanglongbing, for use in population genetic studies. Analysis of 50 individuals collected from Tokunoshima Island showed that allelic diversity ranged from 5 to 24 alleles per locus, and observed and expected heterozygosities ranged from 0.100 to 0.939 and from 0.222 to 0.926, respectively. These SSR markers can be used to understand the population genetics of D. citri, and the obtained information may be useful in the estimation of population genetic structure, gene flow and invasion routes of D. citri.     

Seasonal fluctuations,spatial distribution and natural enemies of Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) in Iran

Population dynamics of the Asian citrus psyllid Diaphorina citri Kuwayama was studied in two‐week intervals throughout the season on lemon in a citrus orchard in Southern Baluchistan, Iran. Population peaks were observed in March, April and September 2007 to January 2008. Population levels were positively related to the availability of new shoot flushes, which were in turn related to the weekly minimum temperature. Also, the nymph population peaks were observed in three periods (beginning of March, end of August and end of January). Results indicated that moderate climatic conditions coupled with the flushing of citrus trees are two main factors for an increase of the development and activity of nymphs resulting in pest population increase, while extremes of both high and low temperatures, low relative humidity and high rainfall were detrimental. Four coccinellids (Coleoptera: Coccinellidae), one syrphid (Diptera: Syrphidae), two parasitoids (Hymenoptera) and two spiders (Araneae) were determined as natural enemies of the psyllid in the studied area.     

中国新入侵害虫——桉梳木虱(半翅目:木虱科)

2018年5月,在云南省昆明市金殿森林公园种植的蓝桉树苗上采集到了一种密集发生的木虱,其成虫和若虫均严重危害桉树叶片。经鉴定为桉梳木虱,该种木虱原产于澳大利亚,此前已入侵欧洲、非洲、北美洲、南美洲和亚洲的一些国家,危害桉树。本文提供了桉梳木虱的危害情况和形态鉴别特征,提出了防范扩散危害的措施建议。     

Ultrastructural characterization and multilocus sequence analysis (MLSA) of ‘Candidatus Rickettsiella isopodorum’, a new lineage of intracellular bacteria infecting woodlice (Crustacea: Isopoda)

The taxonomic genus Rickettsiella (Gammaproteobacteria; Legionellales) comprises intracellular bacteria associated with a wide range of arthropods including insects, arachnids and crustaceans. The present study provides ultrastructural together with genetic evidence for a Rickettsiella bacterium in the common rough woodlouse, Porcellio scaber (Isopoda, Porcellionidae), occurring in Germany, and shows that this bacterium is very closely related to one of the same genus occurring in California that infects the pill bug, Armadillidium vulgare (Isopoda, Armadillidiidae). Both bacterial isolates displayed the ultrastructural features described previously for crustacean-associated bacteria of the genus Rickettsiella, including the absence of well-defined associated protein crystals; occurrence of the latter is a typical characteristic of infection by this type of bacteria in insects, but has not been reported in crustaceans. A molecular systematic approach combining multilocus sequence analysis (MLSA) with likelihood-based significance testing demonstrated that despite their distant geographic origins, both bacteria form a tight sub-clade within the genus Rickettsiella. In the 16S rRNA gene trees, this sub-clade includes other bacterial sequences from woodlice. Moreover, the bacterial specimens from P. scaber and A. vulgare are found genetically or morphologically different from each of the four currently recognized Rickettsiella species. Therefore, the designation ‘Candidatus Rickettsiella isopodorum’ is introduced for this new lineage of isopod-associated Rickettsiella bacteria.     

“Candidatus Haloectosymbiotes riaformosensis” (Halobacteriaceae), an archaeal ectosymbiont of the hypersaline ciliate Platynematum salinarum

The novel ciliate Platynematum salinarum (Scuticociliatia) was isolated only recently from a thalassohaline solar saltern pond (12%) in Portugal. Scanning electron microscopy showed numerous bacterial-shaped cells covering the complete surface of the ciliate. The rod-shaped epibionts were identified and characterized following the “Full-Cycle rRNA Approach”. The almost full-length 16S rRNA gene sequence was obtained using archaeal-specific primers and two species-specific probes were designed for fluorescence in situ hybridization. The 16S rRNA gene sequence of the epibiotic cells showed 87% sequence identity with the type strain sequence of the closest characterized species Halolamina pelagica. Phylogenetic reconstructions affiliated the novel organism to the genus Halolamina (Halobacteria, Archaea). Attempts to isolate the epibionts failed and, therefore, growth experiments incorporating the antibiotic anisomycin were conducted in order to investigate the potential symbiotic relationship between P. salinarum and the epibionts. The results suggested an obligate symbiosis between the two organisms and revealed the first symbiotic representative of the Halobacteria. Based on the phylogenetic analyses and growth experiments we propose the classification of this novel organism in a new genus, with the taxon name “Candidatus Haloectosymbiotes riaformosensis”.     

First record of the Australian psyllid Ctenarytaina spatulata Taylor (Homoptera: Psyllidae) in Europe

Abstract: The Australian species Ctenarytaina spatulata Taylor (Homoptera: Psyllidae) is reported from Europe for the first time. In August of 2002, it was recorded in several eucalyptus plantations in central Portugal. During August and September of 2002, the insect was apparently circumscribed to the area between rivers Douro and Tagus, being absent in the North and South of the country. In February of 2003, C. spatulata was already present all over the country and also in every place we inspected in Spain, namely in Galicia, Extremadura and Andalucia regions. The dispersion of the insect suggests that its introduction in Iberian forests is recent. At the moment, damages were observed in plantations located in northern and central Portugal, and also in the north of Spain. Predation on C. spatulata by spiders, green lacewings (Neuroptera, Chrysopidae), hoverflies (Diptera, Syrphidae, Syrphinae), ladybeetles (Coleoptera, Coccinellidae), and minute pirate bugs (Hemiptera, Anthocoridae) was observed in the field.     

无齿木虱属一新种记述（半翅目：木虱总科：木虱科）

记述采自中国上海的无齿木虱属1新种:上海无齿木虱Edentatipsylla shanghaiensis Li et Chen,sp.nov.,给出危害海桐属植物的无齿木虱属名录,并重新组合和提供分种检索表。模式标本分别保存在中国农业大学昆虫标本馆和上海植物园昆虫标本馆。     

Morphological and molecular characterization of a Hirsutella species infecting the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida

The Asian citrus psyllid, Diaphorina citri Kuwayama, is an invasive pest that vectors citrus greening disease, which recently was detected in Florida. Mycosed adult D. citri were collected at four sites in central Florida between September 2005 and February 2006. Observation of the cadavers using scanning electron microscopy revealed that the pathogen had branched synnemata supporting monophiladic conidiogenous cells. A high-fidelity polymerase chain reaction (PCR) assay was used to amplify the 18S rRNA, 28S rRNA and beta-tubulin genes of the pathogen for phylogenetic analysis. The morphological and genetic data indicated that the pathogen was a novel isolate related to Hirsutella citriformis Speare. PCR assays using isolate-specific primers designed from the unique putative intron region of the beta-tubulin sequence distinguished the psyllid pathogen from five related Hirsutella species. The pathogen was maintained in vivo by exposing healthy D. citri to the synnemata borne on field-collected cadavers. Infected psyllids had an abundance of septate hyphal bodies in their hemolymph and exhibited behavioral symptoms of disease. In vitro cultures of the pathogen were slow-growing and produced synnemata similar to those found on mycosed D. citri. In laboratory bioassays, high levels of mortality were observed in D. citri that were exposed to the conidia-bearing synnemata produced in vivo and in vitro.