A New Australian Species of Ctenarytaina Ferris and Klyver (Hemiptera: Psyllidae: Spondyliaspidinae) established in Three Other Countries

The species described in this paper, Ctenarytaina spatulata sp.n., is widely distributed in Australia. Since 1990 it has also been recorded in New Zealand, the U.S.A. (California) and Uruguay.     

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.     

Life table of Tamarixia radiata (Hymenoptera: Eulophidae) on Diaphorina citri (Hemiptera: Psyllidae) at different temperatures

Tamarixia radiata (Waterston, 1922) is the main parasitoid of Diaphorina citri (Kuwayama, 1907), and has been used in classical biological control programs in several countries. The current study investigated the biology and determined the fertility life table of T. radiata in different temperatures, to obtain information to support the establishment of a biological control program for D. citri in Brazil. Fifth-instar nymphs of D. citri were offered to females of T. radiata for parasitism, for 24 h. Then, the parasitoid was removed and the nymphs were placed in incubators at 15, 20, 25, 30, or 35 +/- 1 degrees C, 70 +/- 10% RH, and a 14-h photophase. The percentages of parasitism and emergence, the sex ratio, and the preimaginal period of T. radiata were determined. The fertility life table was developed from the biological data. The highest parasitism rate (77.24%) was obtained at a temperature of 26.3 degrees C, and the lowest parasitism rates occurred at 15 and 35 degrees C (23.1 and 40.2%, respectively). The highest percentages of emergence of the parasitoid occurred at 25, 30, and 35 degrees C (86.7, 88.3, and 78.8%, respectively), with the calculated peak at 30.8 degrees C (89.90%). The duration of the preimaginal developmental period for both females and males of T. radiata was inversely proportional to temperature in the thermal range of 15-35 degrees C. The development of T. radiata occurred at all temperatures studied, and the highest viability of the preimaginal period occurred at 25 degrees C. The highest values of net reproductive rate and finite growth ratio (lambda) were observed at 25 degrees C, so that in each generation the population of T. radiata increased 126.79 times, higher than the values obtained at the other temperatures.     

Sampling of Cacopsylla pyri (Hemiptera: Psyllidae) and Pilophorus gallicus (Hemiptera: Miridae) in pear orchards

The psyllid Cacopsylla pyri L. (Hemiptera: Psyllidae), is one of the principal pests of pear (Pyrus spp.) orchards and, along with its natural enemies, needs to be carefully monitored for correct integrate pest management and biological pest control decision making. We compare sampling techniques and develop sampling methods for C. pyri and Pilophorus gallicus Remane (Heteroptera: Miridae). Four pear orchards were sampled periodically from 2007 to 2010 in southern Spain by beating branches into funnels or 45-cm-diameter nets and taking shoot samples. Different sampling techniques were compared, and several sampling methods were assayed for adults and nymphs of C. pyri and P. gallicus. Psylla adult and P. gallicus counts in the nets and funnels were similar and closely correlated. Counts of C. pyri adults in the funnels and nets were higher than on shoots, but all measures were closely correlated. The number of nymphs on shoots and leaves was correlated, as were the counts on leaves within shoots. A guide for choosing the sampling unit in cost/precision terms is given. C. pyri nymphs and adults showed an aggregated distribution, whereas P. gallicus had a less-crowded spatial distribution. Enumerative sequential sampling was evaluated for both insects by using the different sampling techniques by resampling experimental data. The negative binomial distribution fitted the experimental data gathered using the different sampling techniques for C. pyri adults and P. gallicus. The use of binomial sampling is discussed for the two insects and the costs involved are compared with those implied in the sequential enumerative method.     

The Effect of Flower Maturity and Harvest Timing on Floral Extract fromBoronia megastigma(Nees)

Development of floral organs during maturation of flower budsinto fully open boronia flowers is described. The petals andfunctional anthers attain their maximum size prior to the non-functionalanthers and the stigma. Organoleptic properties of the floralextract change with successive stages of bud development. Theconcentrations of extract and volatiles in the extract (% byf. wt) increase as buds mature, the extract concentration beinghighest in large buds and open flowers and the concentrationof volatile compounds being highest in open flowers. The rateof flower and extract development was measured. Yields of flowermaterial and floral extract per plant, and the concentrationof total volatiles including ß-ionone reach maximumlevels when 70% of flowers have reached anthesis. All measuredfactors decline after this point, except extract concentration(% of f. and d. wt) which is maintained up to 83% open flowers. Boronia megastigma(Nees); brown boronia; Rutaceae; flower development; floral extract; solvent extraction; ß-ionone; essential oils     

Comparative seed morphology of Boronia and related genera (Boroniinae: Rutaceae) and its systematic implications

Comparative seed morphology of Boronia Sm., Boronella Baill., Neobyrnesia J. A. Armstr. and Zieria Sm., 31 taxa in total, in Rutaceae is studied. The seeds are ventrally ellipsoid to ovoid (0.93–4.42 × 0.50–2.31 × 0.95–2.70 mm). Colour is brown to black. An elaiosome which is related to myrmechocory was observed in Boronella, Boronia, Neobyrnesia and Zieria. Six testa surface pattern types are identified: Type I (Boronia sect. Boronia) – smooth, and cells not barely discernable; Type II (Boronella) – smooth and cells more or less rectangular and often cells elongated; Type III (Boronia sects. Boronia, Cyanothamnus, Imbricatae and Valvatae, Neobyrnesia) – colliculate with four subtypes by presence, absence of ridges or ridge characters; Type IV (Boronia sect. Alatae) – digit form; Type V (Boronia sect. Algidae) – alveolate; Type VI (Zieria) – ridged, the interridge area formed by both cells that form the ridges and cells that do not form the ridges. Seed morphology, especially testa surface patterns, was partially congruent with the current classification of Boronia, with most sections having apomorphies, and provided additional support for the placement of Boronella near Boronia sect. Boronia. Hilum (surrounded by labiose margin or not) and elaiosome shape also offer useful diagnostic characters for Boronia at infrageneric levels. Neobyrnesia and Zieria both had unique testa surface patterns. The seed morphological data contribute to our understanding of systematic relationship in the subtribe Boroniinae.     

Occurrence of Ctenarytaina eucalypti (Maskell) (Hemiptera: Psyllidae) and its natural enemy Psyllaephagus pilosus Noyes (Hymenoptera: Encyrtidae) in Eucalyptus globulus in the state of Rio Grande do Sul, Brazil

Eucalyptus are hosts of several psyllid species. Among them, Ctenarytaina eucalypti (Maskell) is considered the most harmful to Eucalyptus globulus plantations. In Brazil, this pest has been observed in the state of Parana, and in 2005, it was found causing damage to plantations of E. globulus in Arroio Grande and Piratini cities, RS. The monophagous endoparasitoid Psyllaephagus pilosus Noyes was also observed parasitizing nymphs of C. eucalypti. This parasitoid has been shown to be highly efficient in controlling this psyllid species, making unnecessary the use of any other control method.     

Morphogenesis of galls induced by Baccharopelma dracunculifoliae (Hemiptera: Psyllidae) on Baccharis dracunculifolia (Asteraceae) leaves.

The commonest insect gall on Baccharis dracunculifolia (Asteraceae) leaves is induced by Baccharopelma dracunculifoliae (Hemiptera, Psyllidae). The gall-inducing insect attacks young leaves in both the unfolded and the fully expanded stages. Four developmental phases were observed in this type of gall: 1) A folding phase, during which the leaf lamina folded upward alongside the midrib and the edges of the upper portion of the leaf approached each other, forming a longitudinal slit. A single chamber was formed on the adaxial surface of the leaf; 2) A swelling phase, in which the folded leaf tissues thickened and the edges of the leaf drew closer together, narrowing the slit. In this phase the gall matured, turning succulent, fusiform and pale green. The single nymphal chamber was lined with white wax and was able to house from one to several nymphs; 3) A dehiscence phase, characterized by the opening of the slit to release inducers; and 4) A senescence phase, when the gall turned dark and dry. The dermal system of the mature gall was composed of a single-layered epidermis. The mesophyll was swollen, and the swelling was due mainly to hyperplasia of the parenchyma. The vascular tissues along the midrib vein were conspicuous and the perivascular fibers resembled parenchymal cells. The hypertrophied secretory cavities contained low lipophylic content. This gall does not form nutritive tissue, but salivary sheaths left by the inducers were observed near the parenchyma, vascular bundles and secretory cavities. This study complements our current knowledge of gall biology and sheds further light on the plasticity of plant tissues stimulated by biotic factors.     

Preliminary resistance screening on abamectin in pear psylla (Hemiptera: Psyllidae) in northern Italy

In northern Italy (Emilia-Romagna region), integrated pest management has been used for several years against pear psylla, Cacopsylla pyri L. (Hemiptera: Psyllidae), a relevant pest of pear (Pyrus spp.) trees. After the outlawing of amitraz in 2005, the most common active ingredient involved is abamectin, a mixture of avermectin B1a and avermectin B1b. After the development of C. pyri resistance to azinphos methyl in southern France, we evaluated, by topical application, the different sensitivities to abamectin on C. pyri populations collected in orchards from Emilia-Romagna, where different field strategies were used, with alternative success in terms of pest management. The LC50 values ranged between 1.61 and 28.37 mg/liter, and they revealed variations more related to collection time than to field strategies. The failure of abamectin treatments against C. pyri in some Emilia-Romagna locations is probably unrelated to resistance development, but rather it is related to incorrect pest defense management, which could interfere with pest parasitoids and predators.     

Dispersion patterns and sampling plans for Diaphorina citri (Hemiptera: Psyllidae) in citrus

The abundance and spatial dispersion of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) were studied in 34 grapefruit (Citrus paradisi Macfad.) and six sweet orange [Citrus sinensis (L.) Osbeck] orchards from March to August 2006 when the pest is more abundant in southern Texas. Although flush shoot infestation levels did not vary with host plant species, densities of D. citri eggs, nymphs, and adults were significantly higher on sweet orange than on grapefruit. D. citri immatures also were found in significantly higher numbers in the southeastern quadrant of trees than other parts of the canopy. The spatial distribution of D. citri nymphs and adults was analyzed using Iowa's patchiness regression and Taylor's power law. Taylor's power law fitted the data better than Iowa's model. Based on both regression models, the field dispersion patterns of D. citri nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. For the average density of each life stage obtained during our surveys, the minimum number of flush shoots per tree needed to estimate D. citri densities varied from eight for eggs to four flush shoots for adults. Projections indicated that a sampling plan consisting of 10 trees and eight flush shoots per tree would provide density estimates of the three developmental stages of D. citri acceptable enough for population studies and management decisions. A presence-absence sampling plan with a fixed precision level was developed and can be used to provide a quick estimation of D. citri populations in citrus orchards.     

Volatiles in Different Floral Organs, and Effect of Floral Characteristics on Yield of Extract fromBoronia megastigma(Nees)

The relative amounts of volatile compounds in the extract andheadspace from each floral organ were assessed in order to identifythe main organs for accumulation and emission. The mass of flowers/organs,the number/density of oil glands and yield of volatiles wereexamined for their relationship with extract yield, in clonaland non-clonal plants. Boronia flowers were divided into componentorgans and the solvent extractable product and headspace aboveeach organ type was quantified. The petals comprised 50% ofthe weight of the flowers, and the stigma 20%; however, thestigma contributed 70% of the total volatile compounds to extractfrom the whole flower. Proportionately more ß-iononeand dodecyl acetate were emitted from the stigma and anthersthan were contained in the extract, compared with other volatiles.The sexual organs are morphologically equipped for emissionof volatiles to attract pollinators. Between non-clonal plants, there was a lower coefficient ofvariation for extract yield than for values relating to extractcomposition, indicating that the former is more heritable thanthe latter. Variation between clonal plants was reduced comparedwith variation between non-clonal plants. The environment modifiesyield and quality of extract in clonal plants, indicating thatboth have relatively low heritability. No significant relationshipsbetween any floral characteristics and extract yield were found.Biosynthetic potential to accumulate extract is therefore ofprime importance, and the effect of environment on this potentialshould be the subject of future work. Boronia megastigma; brown boronia; Rutaceae; essential oils; flower; stigma; oil gland; ß-ionone     

Phytochemical and chemotaxonomic study on Dictamnus angustifolius G. Don ex Sweet (Rutaceae)

A phytochemical investigation of Dictamnus angustifolius led to the isolation of 14 compounds, including six furoquinoline alkaloids (1–6), two sesquiterpenoids (7, 8) and six flavonoids (9–14). The structures of these compounds were identified by spectroscopic methods and a comparison of their data with those reported in the literature. This is the first report of three furoquinoline alkaloids 1–3 and six flavonoids 9–14 from the genus Dictamnus and the first isolation of compounds 4–8 from D. angustifolius. The chemotaxonomic significance of furoquinoline alkaloids and sesquiterpenoids has also been summarized.     

Temperature-Dependent Fecundity and Life Table of the Fennel Aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae)

Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a cosmopolitan species and the main pest of fennel in northeastern Brazil. Understanding the relationship between temperature variations and the population growth rates of H. foeniculi is essential to predict the population dynamics of this aphid in the fennel crop. The aim of this study was to measure the effect of constant temperature on the adult prereproductive period and the life table fertility parameters (infinitesimal increase ratio (r_m), gross reproduction rate (GRR), net reproduction rate (R₀), finite increase ratio (λ), generation time (GT), the time required for the population to double in the number of individuals (DT), and the reproduction value (RV_x)) of the fennel pest H. foeniculi. The values of lx (survival of nymphs at age x) increased as the temperature rose from 15 to 28°C and fell at 30°C, whereas mx (number of nymphs produced by each nymph of age x) increased from 15 to 25°C and fell at 28 and 30°C. The net reproduction rates (R₀) of populations of H. foeniculi increased with temperature and ranged from 1.9 at 15°C to 12.23 at 28°C for each generation. The highest population increase occurred with the apterous aphids at 28°C. The rate of population increase per unit time (r_m) (day) ranged from 0.0033 (15°C) to 0.1995 (28°C). The highest values of r_m were recorded at temperatures of 28°C and 30°C. The r_m values were a good fit to the models tested, with R² > 0.91 and R² _adj > 0.88. The models tested (Davidson, Sharpe and DeMichele modified by Schoolfield et al., Logan et al., Lamb, and Briere et al.) were very good fits for the r_m values observed, with R² > 0.91 and R² _adj > 0.88. The only exception was the Davidson model. Of the parameters studied, the reproductive capacity was higher in the apterous aphids, with the unique exception of daily fecundity at 28°C, which was higher in the alate aphids of H. foeniculi. Parameters relating to the age-specific fertility table for H. foeniculi were heavily influenced by temperature, with the highest biotic potential and population growth capacity found at 34°C. Therefore, the results obtained in this study could be of practical significance for predicting outbreaks of fennel aphids and improving the management of this aphid in fennel crops.     

Population ecology and phenology of Diaphorina citri (Hemiptera: Psyllidae) in two Florida citrus groves

Studies were conducted to assess population densities and phenology of the psyllid Diaphorina citri Kuwayama at two citrus groves in east-central Florida. One grove contained young, irrigated grapefruit trees and the other contained mature, nonirrigated orange trees. The two groves were sampled weekly for eggs, nymphs, and adults on flush shoots; for adults on mature leaves; and for adults captured on yellow sticky card traps. Because infestations of immature D. citri develop strictly on young flush, the abundance of flush was assessed weekly. Overall means of 26.5, 16.8, and 0.27 eggs, nymphs, and adults per flush shoot, respectively, were observed in the young grapefruit trees. In the grove of mature orange trees, overall means of 16.0, 12.7, and 0.31 eggs, nymphs, and adults per flush shoot were observed, respectively. Flush abundance was an inconsistent indicator of the mean density of D. citri per flush shoot. Mean density per shoot by itself was an inconsistent indicator of overall population levels of D. citri at each study site because few shoots were sometimes present when mean densities per shoot were high. May, June, and July were periods of time when immature D. citri were consistently present and most abundant at each study site, but the study indicated large infestations could occur at any time of the year depending on environmental factors and flush availability. Yellow sticky traps were effective for both male and female D. citri and useful for gauging adult population trends.     

Infestation of Glycaspis brimblecombei (Hemiptera: Psyllidae) on three Eucalyptus species in selected ecological zones in Malawi

The study determined variations in incidence, severity and damage of Glycaspis brimblecombei among Eucalyptus species and ecological zones, and the interaction between Eucalyptus species and ecological zones. Additionally, the study determined variation in pest abundance between the upper, middle and lower parts of the tree crown. The study was conducted in six districts located in four ecological zones in Malawi. Eucalyptus stands established in 2014–2016 or coppices from trees cut in that period were sampled for G. brimblecombei infestation. A significant interaction was found between Eucalyptus species and ecological zones on G. brimblecombei infestation. Significant differences were observed between ecological zones in G. brimblecombei infestation with lowest incidence, severity and damage being found in the cooler ecological zone M. Eucalyptus camaldulensis and Eucalyptus tereticornis showed high susceptibility to G. brimblecombei compared to Eucalyptus grandis. There were no significant differences in abundance between the upper, middle and lower tree crown parts of each Eucalyptus species. Control efforts for this psyllid should focus on breeding and planting of resistant Eucalyptus varieties in specifically recommended sites. The uniform distribution of the pest on different tree crown parts implies that use of contact insecticides on a large scale would be tedious and expensive.     

Life history and life tables of Bactericera cockerelli (Hemiptera: Psyllidae) on potato under laboratory and field conditions in the lower Rio Grande Valley of Texas

Effective management of potato 'Zebra Chip' (ZC) disease caused by Cadidatus Liberibacter psyllaurous (syn. solanacearum) depends on the management of its insect vector insect, potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae). To elucidate the age-specific population dynamics of B. cockerelli, the life-table parameters were determined on potato, Solanum tuberosum L., under both laboratory and field conditions in the Lower Rio Grande Valley (LRGV) of Texas. Generally, survival, fecundity, and longevity of B. cockerelli were significantly greater under laboratory than under field conditions. The mortality under laboratory conditions was mainly due to natural intrinsic mortality. However, under field conditions, most (83.2%) B. cockerelli were missing, and of those that were not, they developed slower, and had shorter preoviposition period, shorter oviposition period, shorter longevity, lower fecundity, and higher mortality than those under laboratory conditions. As a result, most of the life-table parameters of B. cockerelli, including the intrinsic rate of increase, finite rate of increase, and net reproductive rate, were significantly lower in the field under the environmental conditions of the LRGV of Texas than in the laboratory. The information could help increase our understanding of the epidemiology of the ZC diseases associated with the pathogens transmitted by this insect pest.     

蜡蝉总科(昆虫纲:半翅目)系统分类研究进展

蜡蝉总科隶属于半翅目头喙亚目,大致可分为18～21个科。中国记载16科。蜡蝉总科的科级系统发育关系一直存在着广泛争议,至今尚无一个为大多数学者所接受的分类系统。因此,研究蜡蝉总科的系统发育具有重要的理论价值。本文从种及种下阶元的分类鉴定、种上阶元的系统发育、生物地理学等方面对蜡蝉总科的分类研究进行综述。     

Inhibition of trehalase affects the trehalose and chitin metabolism pathways in Diaphorina citri (Hemiptera: Psyllidae)

The Asian citrus psyllid, Diaphorina citri is the principal vector of huanglongbing, which transmits Candidatus Liberibacter asiaticus. Trehalase is a key enzyme involved in trehalose hydrolysis and plays an important role in insect growth and development. The specific functions of this enzyme in D. citri have not been determined. In this study, three trehalase genes (DcTre1-1, DcTre1-2, and DcTre2) were identified based on the D. citri genome database. Bioinformatic analysis showed that DcTre1-1 and DcTre1-2 are related to soluble trehalase, whereas DcTre2 is associated with membrane-bound trehalase. Spatiotemporal expression analysis indicated that DcTre1-1 and DcTre1-2 had the highest expression levels in the head and wing, respectively, and DcTre2 had high expression levels in the fat body. Furthermore, DcTre1-1 and DcTre1-2 expression levels were induced by 20-hydroxyecdysone and juvenile hormone Ⅲ, but DcTre2 was unaffected. The expression levels of DcTre1-1, DcTre1-2, and DcTre2 were significantly upregulated, which resulted in high mortality after treatment with validamycin. Trehalase activities and glucose contents were downregulated, but the trehalose content increased after treatment with validamycin. In addition, the expression levels of chitin metabolism-related genes significantly decreased at 24 and 48 h after treatment with validamycin. Furthermore, silencing of DcTre1-1, DcTre1-2, and DcTre2 reduced the expression levels of chitin metabolism-related genes and led to a malformed phenotype of D. citri. These results indicate that D. citri trehalase plays an essential role in regulating chitin metabolism and provides a new target for control of D. citri.     

亚洲柑橘木虱与柑橘黄龙病菌互作的研究进展

亚洲柑橘木虱Diaphorina citri Kuwayama作为柑橘产业重要病害柑橘黄龙病的主要传播媒介,已经成为重点防治对象。该害虫与黄龙病之间的互作一直是相关研究的热点,本文就近年来该领域的研究进展做了一个总结,从亚洲柑橘木虱的获菌与传病机制、病原菌与柑橘木虱之间的互作以及病原菌感染寄主植物后对木虱的影响等方面进行了综述。期望为深入开展黄龙病相关研究、寻找防控新途径提供依据。     

Life Table Parameters of Three Mirid Bug (Adelphocoris) Species (Hemiptera: Miridae) under Contrasted Relative Humidity Regimes

The genus Adelphocoris (Hemiptera: Miridae) is a group of important insect pests of Bt cotton in China. The three dominant species are A. lineolatus, A. suturalis, and A. fasciaticollis, and these species have different population dynamics. The causal factors for the differences in population dynamics have not been determined; one hypothesis is that humidity may be important for the growth of Adelphocoris populations. In the laboratory, the demographic parameters of the three Adelphocoris species were compared when the mirid bugs were subjected to various levels of relative humidity (40, 50, 60, 70 and 80% RH). Middle to high levels of RH (60, 70 and 80%) were associated with higher egg and nymph survival rates and increased adult longevity and female fecundity. Lower humidity levels (40 and 50% RH) had negative effects on the survival of nymphs, adult longevity and fecundity. The intrinsic rate of increase (r_m), the net reproductive rate (R₀) and the finite rate of increase (λ) for each Adelphocoris species increased with increasing RH. Significant positive relationships were found between RH and the life table parameters, r_m, R₀ and λ for the three Adelphocoris species. These results will help to better understand the phenology of the three Adelphocoris species, and the information can be used in population growth models to optimize pest forecasting and management strategies for these key pests.