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Dr Roger Laurence Blackman (Fig. 1) passed away on 17 March 2022, after more than 50 years dedicated to advances in aphid science. There can be very few scientists studying any aspect of aphids whose papers have not cited the works of Roger Blackman. To his name, we add that of Victor Eastop (1924–2012), for the two of them formed an inspirational, complementary and indefatigable pair at London’s Natural History Museum. Together they were responsible for, amongst many other seminal works, the three testaments of the aphidologists’ bible: Aphids on the World’s Crops, Aphids on the World’s Trees and Aphids on the World’s Herbaceous Plants and Shrubs, now brought together and regularly updated by Roger until very recently in the online version, Aphids on the World’s Plants (www.aphidsonworldsplants.info). Victor was an out-and-out taxonomist, absolutely amongst the best the world has known, whilst being very familiar with most aspects of aphidology. Roger’s contributions were broader as we shall see. more...

Manuscript Version 3 - accepted by the IEEE Journal of Photovoltaics. The final version is available at https://doi.org/10.1109/JPHOTOV.2023.3242117 Abstract: Bifacial photovoltaic modules are able to convert the solar radiation reaching their front and rear-sides, which means that more electricity can be produced using the same array area as monofacial modules with similar ratings. In some locations, the cost per power unit for such a technology has already become cost-competitive with conventional monofacial modules. The so-called effective irradiance and the bifacial gain are useful metrics, respectively, to assess the solar resource and the performance of bifacial arrays. To calculate the effective irradiance, studies previously published employ rear-side irradiance measurements, whereas to compute the bifacial gain, other works make use of monofacial modules with rating similar to those of the bifacial modules under analysis. In this paper, a straightforward method is presented, allowing to calculate the effective irradiance from the maximum power current, and to calculate the bifacial gain using a power scaling relation. The proposed method was experimentally tested using an outdoor platform with a dual-axis tracking system with bifacial modules. The effective irradiance calculated using the novel method presented nRMSE of 2.88 %, relative to the results obtained using the consolidated method. The bifacial gains obtained were 6.24 % and 6.69 %, respectively, using the proposed and traditional calculation methods. The procedure presented in this study might be useful for the quantification of the effective irradiance and the bifacial gain for PV installations which do not have extensive monitoring hardware. more...

Bifacial photovoltaic modules are able to convert the solar radiation reaching their front and rear-sides, which means that more electricity can be produced using the same array area as monofacial modules with similar ratings. In some locations, the cost per power for such a technology has become cost-competitive with onventional monofacial modules. The so-called effective irradiance and the bifacial gain are useful metrics, respectively, to assess the solar resource and the performance of bifacial arrays. To calculate the effective irradiance, studies previously published employ rear-side irradiance measurements. In turn, to compute the bifacial gain, other works make use of monofacial modules with rating similar to those of the bifacial modules under analysis. In this paper, a straightforward method is presented, allowing the calculation of the effective irradiance without the requirement of measuring the rear-side irradiance; and to calculate the bifacial gain without the need of a monofacial module. The proposed method was experimentally tested using an outdoor platform with a dual-axis tracking system with bifacial modules. The international standard IEC-60891 was taken as a reference for monofacial power calculations, showing coherent results when compared to the calculated front-side bifacial module performance. The method should be useful for the quantification of the effective irradiance and the bifacial gain for PV installations which do not make use of extensive monitoring hardware. more...

Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are some of the least understood insects, particularly in agriculture, even though they can cause high crop losses. Due to their small size and cryptic habits they are rarely noticed at the onset of an infestation. In Kenya, efforts have been initiated to understand these pests better. Scale insects from Kenya, found in samples between 13 and 107 years old, were studied in the insect collections of the Natural History Museum, London, U.K. and the Kenya Agriculture and Livestock Research Organisation, Nairobi, Kenya. The study identified 51 new country records of scale insects including one new continental record for Africa, Ferrisia dasylirii (Cockerell) (Pseudococcidae). Of the new records, 35 species (68.6%) are native to Africa and 16 (31.4%) have been introduced from elsewhere. Six of the 51 species (11.8%) are pests in Kenya today. Amongst the introduced species, at least one (Aonidiella comperei McKenzie) could cause plant quarantine issues in trade, and four (25.0%) are pests, more than four times the frequency of pests amongst the African species (5.7%). The remaining 45 species have been present in Kenya for at least 13 years and many have not been collected again since the original samples, suggesting that either they have not survived or they are rare because they are under good natural control. Most of the introduced species listed (75.0%) have not caused economic problems in Kenya to date, so it is thought unlikely that they will do so in the future. Key words: Scale insects, introduced species, native species more...

The Psylloidea contains species that can transmit pathogens to plants, including important agricultural crops e.g. the proteobacterium 'Candidatus Liberibacter solanacearum' (CaLsol) to potatoes. To obtain a better understanding of British psyllid populations, a study was conducted over two years to determine their aerial incidence and diversity using an existing network of 12.2 m suction traps. In total, 42 species were detected in the traps. In 2015 in England, the most common species was the grouping of Cacopsylla melanoneura and C. affinis followed by Trioza remota (the latter being most prevalent in autumn). In contrast, in Scotland Cacopsylla species (melanoneura, affinis, pulchra and brunneipennis) accounted for 81% of the population in spring and summer. The yearly sampling in England in 2015 revealed that the aerial movement of the most common species differed in their phenology. The grouping of Cacopsylla melanoneura and C. affinis, as well as T. urticae were most common in summer whereas T. remota was most prevalent in late autumn. Three species new to Britain: Cacopsylla alaterni, Trioza anthrisci and Ctenarytaina spatulata were caught during sampling, in addition to Trioza apicalis which transmits CaLsol. Following our study, the British psyllid checklist was revised and is presented here. The potential of suction traps for monitoring and detecting more...

Asialeyrodes radiata Pushpa & Sundararaj is proposed here as a junior synonym of A. splendens Meganathan & David. An updated key to puparia of genus Icfrealeyrodes is provided.

Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are obligate plant parasites feeding on plant sap; some are damaging pests in agriculture, horticulture and forestry. Despite their economic importance, the scale insects found in continental Africa have not been extensively studied and the keys for identifying them are incomplete and scattered through the literature in several languages. The aim of this study is to improve our understanding of the African scale insect fauna. As a first step towards their identification, we provide a key to the 23 families currently known from continental Africa, based on slide-mounted adult females, covering Aclerdidae, Asterolecaniidae, Cerococcidae, Coccidae, Conchaspididae, Dactylopiidae, Diaspididae, Eriococcidae, Halimococcidae, Kermesidae, Kerriidae, Kuwaniidae, Lecanodiaspididae, Margarodidae, Matsucoccidae, Micrococcidae, Monophlebidae, Ortheziidae, Phoenicococcidae, Pseudococcidae, Putoidae, Rhizoecidae and Stictococcidae. more...

Smallholder farmers represent the majority of food producers around the world, yet they are often the most at risk of suffering yield gaps and not achieving their production potential. Ecological Intensification (EI) is a knowledge intensive approach to sustainable agricultural intensification which utilizes biodiversity‐based ecosystem services to support greater yield and reduce reliance on agrochemical inputs. Despite the potential benefit of EI based practices, uptake by smallholders is not as widespread as it could be. Here we test the hypothesis that application of EI on smallholder farms in Kenya is a viable approach that could be taken in order to enhance food security. Focusing on natural pest control and crop pollination, we used farmer surveys to explore the potential for EI in central Kenya. We identified to what extent farm typology and access to knowledge determine the incentives and barriers facing smallholder producers and how this influences optimal pathways for sharing knowledge and providing extension services. We found considerable potential for EI of smallholder farms in this region; most farmers grew insect pollinated crops and some farmers already employed EI practices, while others relied heavily on chemical pesticides. Based on physical, social, and economic factors, three farm typologies emerged including “semi‐commercial,” “market orientated,” and “subsistence.” These typologies influenced the appropriate EI practices available to farmers, as well as routes through which knowledge was shared, and the extent to which extension services were utilized. We propose that to support effective uptake of EI practices, smallholder farm heterogeneity should be acknowledged and characterized in order to target the needs and capabilities of farmers and identify appropriate knowledge sharing and support pathways. The approach we take here has the potential to be employed in other regions globally. more...

Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are a superfamily of small phloem-feeding insects. They rely on their primary endosymbionts "Candidatus Portiera aleyrodidarum" to produce essential amino acids not present in their diet. Portiera has been codiverging with whiteflies since their origin and therefore reflects its host’s evolutionary history. Like in most primary endosymbionts, the genome of Portiera stays stable across the Aleyrodidae superfamily after millions of years of codivergence. However, Portiera of the whitefly Bemisia tabaci has lost the ancestral genome order, reflecting a rare event in the endosymbiont evolution: the appearance of genome instability. To gain a better understanding of Portiera genome evolution, identify the time point in which genome instability appeared and contribute to the reconstruction of whitefly phylogeny, we developed a new phylogenetic framework. It targeted five Portiera genes and determined the presence of the DNA polymerase proofreading subunit (dnaQ) gene, previously associated with genome instability, and two alternative gene rearrangements. Our results indicated that Portiera gene sequences provide a robust tool for studying intergenera phylogenetic relationships in whiteflies. Using these new framework, we found that whitefly species from the Singhiella, Aleurolobus, and Bemisia genera form a monophyletic tribe, the Aleurolobini, and that their Portiera exhibit genome instability. This instability likely arose once in the common ancestor of the Aleurolobini tribe (at least 70 Ma), drawing a link between the appearance of genome instability in Portiera and the switch from multibacteriocyte to a single-bacteriocyte mode of inheritance in this tribe. more...

A new Eocene species of Psylloidea is described from Baltic amber. Eogyropsylla pankowskii Ashe-Jepson & Ouvrard sp. nov., along with E. magna and E. parva, is micro- computed tomography (CT) scann... more...

The accurate and rapid identification of insect pests is an important step in the prevention and control of outbreaks in areas that are otherwise pest free. The potato-tomato psyllid Bactericera cockerelli (Sulc, 1909) is the main vector of 'Candidatus Liberibacter solanacearum' on potato and tomato crops in North America and New Zealand; and is considered a threat for introduction in Europe and other pest-free regions. This study describes the design and validation of the first species-specific TaqMan probe-based real-time PCR assay, targeting the ITS2 gene region of B. cockerelli. The assay detected B. cockerelli genomic DNA from adults, immatures, and eggs, with 100% accuracy. This assay also detected DNA from cloned plasmids containing the ITS2 region of B. cockerelli with 100% accuracy. The assay showed 0% false positives when tested on genomic and cloned DNA from 73 other psyllid species collected from across Europe, New Zealand, Mexico and the USA. This included 8 other species in the Bactericera genus and the main vectors of 'Candidatus Liberibacter solanacearum' worldwide. The limit of detection for this assay at optimum conditions was 0.000001ng DNA (similar to 200 copies) of ITS2 DNA which equates to around a 1:10000 dilution of DNA from one single adult specimen. This assay is the first real-time PCR based method for accurate, robust, sensitive and specific identification of B. cockerelli from all life stages. It can be used as a surveillance and monitoring tool to further study this important crop pest and to aid the prevention of outbreaks, or to prevent their spread after establishment in new areas. more...

Psyllids (Hemiptera: Psylloidea) can transmit the phloem restricted bacterium &lsquo, Candidatus Liberibacter solanacearum&rsquo, (Lso). In Europe, Lso causes severe losses to carrot and represents a threat to the potato industry. A rising concern is Lso transmission from carrot to potato and within potato, and this has driven the need for monitoring populations of psyllid species which could serve as vectors on both crops. This would provide a fundamental understanding of the epidemiology of Lso. Different sampling methods were used to survey populations of psyllid species in commercial carrot and potato fields in central and eastern mainland Spain from 2015 to 2017. Two psyllid species, Bactericera trigonica and Bactericera nigricornis were found on carrot and potato crops. In carrot fields the most abundant species was B. trigonica (occurring from crop emergence to harvest), whereas in potato crops the most abundant psyllid species was B. nigricornis. Depending on field location, the maximum psyllid populations occurred between June and October. Since B. nigricornis was found on both carrot and potato and is the only psyllid species able to feed and reproduce on both these crops in Europe, there is the potential risk of Lso transmission from carrot to potato. more...

Psyllids (Hemiptera: Psylloidea) can transmit the phloem restricted bacterium ‘Candidatus Liberibacter solanacearum’ (Lso). In Europe, Lso causes severe losses to carrot and represents a threat to the potato industry. A rising concern of Lso transmission from carrot to potato and within potato has driven the need for monitoring populations of psyllid species that could serve as vectors on both crops, which would provide a fundamental understanding of the epidemiology of this pathogen. Different sampling methods were used to survey populations of psyllid species in commercial carrot and potato fields in Central and Eastern mainland Spain from 2015 to 2017. Two psyllid species, Bactericera trigonica and Bactericera nigricornis were found to be mainly associated with carrot and potato crops. In carrot fields the most abundant species was B. trigonica occurring from crop emergence to harvest, whereas in potato crops the most abundant psyllid species was B. nigricornis. The maximum psyllid population occurred between June and October its timing depending on the field location. Since B. nigricornis was found on both carrot and potato and is the only psyllid species able to feed and breed on both these crops in Europe, there is the potential risk of Lso transmission from carrot to potato more...

International audience; The utilization of multi-junction solar cells with high efficiency is still not widespread for terrestrial power applications. These solar cells, composed by several material layers, reach high efficiencies but its cost is expensive, more of 100 higher than classical silicon solar cells. Thus, one solution consists to use reduced sizing solar cells associated with optics mounted on solar tracker to concentrate the solar beam. Numerous meteoro-logical parameters such as beam solar irradiance, ambient temperature and air mass and especially spectral characteristics of sun radiation are involved in the conversion process and are generally used as inputs in power models. Several models from literature, different by their form and by the number and type of input variables, are presented; based on this state-of-art, some similar models are selected and tested on two experimental CPV systems located on two different sites, Ajaccio and Le Bourget du Lac. Then, an operational model of electrical power using inputs easily measured and available for a solar CPV plant operator is developed. It could be used as a decision-aided tool for investors in providing an estimation of the energy production capacity of the CPV systems on the future implantation site. This established model based on data measured on the CPV system in Ajaccio estimates the produced power with a root mean square error of about 5% on the two sites using only a reduced number of inputs. more...

Cassava is a valued calorific source to millions of Africans who eat it daily and a vital staple for their food security. One of the key constraints to this crop is whiteflies which are both a vector of viral diseases and a direct pest. Although the African cassava whitefly is known to cause physical damage on cassava with considerable tuberous yield loss, a recent whitefly outbreak caused unusually severe damage, which prompted the current reported investigation. Molecular identification of whitefly adults sampled from the affected cassava field revealed the presence of a new whitefly species, Paraleyrodes bondari. This communication is the first report of the occurrence of P. bondari on cassava in Uganda. Keywords: East Africa, Invasive, Manihot, New pest, Food security more...

International audience; This is the first substrate-borne communication record of the troglobitic planthopper Typhlobrixia namorokensis in the caves of the Ambovonomby network, Namoroka Tsingy, Madagascar. A supplementary morphological description of the male genitalia is provided and, for the first time, female genitalia of T. namorokensis are characterized. Molecular data were obtained for T. namorokensis; molecular analysis also reveals the presence of another (yet unidentified) cavernicolous cixiid in the Antsifotra caves network. The evolutionary origin of T. namorokensis is discussed. Its adaptation to caves and its behaviour allows its identification as a true troglobiont. Its vibrational signal structure is compared to the calls of other cave-dwelling cixiids. more...

Specimens of the psyllid, Trioza anthrisci (Triozidae) collected from the United Kingdom and Sweden were positive for the phloem-limited proteobacterium 'Candidatus Liberibacter solanacearum' (Lso). Lso has only been reported in seed in… more...

The genus-group name Chermes Linnaeus 1758 has been suppressed, but an accounting of the various nominal species described in combination with it has not been presented until now. Nominal species of Chermes are found in 13 families of three major lineages of Sternorrhyncha (Aphidomorpha, Coccoidea, Psylloidea). Eleven available names remain unplaceable (incertae sedis nomina dubia) and to date do not appear in the various Sternorrhyncha catalogues. In order to clarify their status, we here present an annotated list of the 137 nominal species-group names originally described in combination with Chermes. We provide the original bibliographic citation and an assessment of the current status of each name. more...

Cacopsylla bidens (Sulc, 1907), feeding on pear trees, is recorded for the first time in Egypt. A short taxonomic presentation of the species is given, as well as some elements of biology.

The triozid Bactericera tremblayi, or onion psyllid, is recorded for the first time from France, and is associated for the first time with important damage on leek crops in several regions of the country. We compare the morphology of this species with the two other species of the B. nigricornis-group, in order to avoid misidentifications, and illustrate the different stages of B. tremblayi. The published distribution of the three species is summarised and updated based on collection data, and the presence of B. tremblayi and B. trigonica in Jordan and Spain (Canary Islands) respectively, is also recorded for the first time. more...

The Nearctic species Prokelisia marginata (Van Duzee, 1897) is recorded for the first time in France, along the English Channel. It was found on Spartina anglica C. E. Hubb. (Poaceae), which is not its original host but a well established cord-grass on that coast. An account is given on the actual known distribution of P. marginata throughout Europe., Prokelisia marginata (Van Duzee, 1897) débarque en France sur les plages normandes (Hemiptera, Fulgoromorpha, Delphacidae). L'espèce néarctique Prokelisia marginata (Van Duzee, 1897) a été observée pour la première fois en France, sur la côte normande. On la trouve sur Spartina anglica C. E. Hubb., Poaceae abondante sur ce littoral, mais qui n'est pas sa plante hôte originelle. La progression de P. marginata en Europe et sa distribution actuelle sont discutées., Ouvrard David, Soulier-Perkins Adeline. Prokelisia marginata (Van Duzee, 1897) lands on the French coast of Normandy (Hemiptera, Fulgoromorpha, Delphacidae). In: Bulletin de la Société entomologique de France, volume 117 (4),2012. pp. 441-444. more...

Liadopsylla apedetica sp.n. Ouvrard, Burckhardt & Azar and L. hesperiasp.n. Ouvrard & Burckhardt are described from Lebanon and New Jersey amber, respectively, constituting the first descriptions of Psylloidea preserved in Cretaceous amber. Liadopsylla hesperia is the first representative of Liadopsyllidae found in the New World. Liadopsylla apedetica is remarkably well preserved, showing conical, mobile metacoxae. This suggests that Liadopsyllidae did not jump the way extant psyllids do. It is proposed that enlarged metacoxae fused with the complex metathoracic furcae constitute a synapomorphy of extant Psylloidea. This trait was first observed in fossils from the Eocene. As such, the inability to jump in a few extant members of Psylloidea is a secondary loss that probably occurred several times independently. The families Liadopsyllidae and Malmopsyllidae are also redefined; within Liadopsyllidae, the genus Mesopsylla is synonymized with Liadopsylla. The origin and palaeobiogeography of the Liadopsyllidae are briefly discussed. more...

This work is an assessment of the biogeographical, taxonomic, biological and phylogenetic knowledge of the poorly defined family Eriococcidae. The study of its geographical diversity shows the richness of the Palearctic fauna on which the present analysis focuses. The numerous systems dealing with the taxonomy of Eriococcidae are detailed, and the specific taxonomical status of the genus Eriococcus, which contains 155 out of the 175 known Palearctic species is reevaluated. The phylogeny of the palaearctic members of the scale insect family Eriococcidae is reconstructed, using 9 genera and 52 species. Three more scale insect species belonging to 3 families were used as outgroups. The cladistic analysis of 130 morphological characters of the adults resulted in 10 most parsimonious trees, placing Eriococcus buxi as the sister-group of all other sampled Eriococcidae. The genera Acanthococcus, Rhizococcus, Greenisca and Anophococcus appear as para- or polyphyletic, but the weakness of most of the clad... more...

Acizzia uncatoides (Psyllidae) and Furcaspis biformis (Diaspididae) new for Reunion island (Hemiptera). Two new Hemiptera are newly recorded from Reunion Island : Acizzia uncatoides (Ferris & Klyver, 1932) (Psyllidae) on Acacia heterophylla (Lam.) Willd. (Fabaceae) and Furcaspis biformis (Cockerell, 1893) (Diaspididae) on Agave sp. (Asparagaceae)., Deux Hémiptères nouveaux pour l’île de la Réunion sont signalés, Acizzia uncatoides (Ferris & Klyver, 1932) (Psyllidae) sur Acacia heterophylla (Lam.) Willd. (Fabaceae) et Furcaspis biformis (Cockerell, 1893) (Diaspididae) sur Agave sp. (Asparagaceae)., Ouvrard David, Streito Jean-Claude, Clain Clarisse, Fontaine Romuald, Germain Jean-François. Acizzia uncatoides (Psyllidae) et Furcaspis biformis (Diaspididae) nouveaux pour l’île de la Réunion (Hemiptera). In: Bulletin de la Société entomologique de France, volume 121 (3),2016. pp. 283-284. more...

The wing articulation sclerites, as well as wing base environment, of phylogenetically distant Psylloidea taxa were examined by optical and electron microscopy in order to estimate the phylogenetic significance of observed morphological patterns. The basiradial bridge is strongly developed and links the fused humeral plate, basisubcostale, basiradiale and second axillary sclerite to the fused veins R + M + Cu. The proximal median plate has a vertical orientation, which may have a role in moving the wing forward and backward. The weak sclerotization posteriad of the second axillary sclerite and anteriad to the third axillary sclerite facilitates the backward movement of the wing. The horizontal hinge (= basal hinge), the vertical hinge and the torsional hinge are the most important fold- and flexion-lines for the mobility of the wing, whereas humeral folds and the anterior axillary fold-line play a minor role. The basalare presents two horns or processes that are autapomorphic traits for the superfamily Psylloidea. The monophyly of Psylloidea is also supported by the absence of the subalare, of the median notal wing process and of the anterior arm of the third axillary sclerite (lacking articulation with second axillary sclerite). Major interspecific variations are observed in tegula, first axillary sclerite and basalare shape and size. The second distal median plate is absent in Homotoma ficus (Homotomidae) and Glycaspis brimblecombei (Spondyliaspidinae), whereas it is present in Calophya schini (Calophyidae) and Psylla buxi (Psyllinae/Arytaininae); the presence of this sclerite could be a synapomorphy linking Calophyidae and the “psyllid assemblage”. more...

To estimate the potential contribution of ethological and ecological parameters to the mechanisms of species formation and species isolation in the Palearctic cicada genus Tibicina, we constructed a molecular phylogenetic hypothesis of extant Tibicina species. Seven mitochondrial genes and a fragment of a nuclear gene were sequenced (3046 bp). Mitochondrial genes included 547 informative sites but the nuclear gene was too conserved to be included in the analysis. The tree was characterized by a basal polytomy indicating that Tibicina species arose rapidly. Such rapid radiation might explain the low divergence in the acoustic communication observed between species. Parameters describing habitat selection and acoustic communication were mapped onto the tree. A shift in habitat selection accompanied by acoustic changes might have contributed to one speciation event. The stochastic distribution of the same acoustic characters on the other branches of the tree implies, however, that the subtle acoustic differences between species could be the result of previous speciation events and independent evolutionary histories, rather than having contributed themselves in the speciation and isolation processes. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 611–626. more...

A total of 68 psyllid species are listed from the Mercantour National Park in Southeast France, where a targeted collecting campaign was conducted between 2009 and 2012, as part of the project "ATBI+M" Mercantour. The insects were collected using Malaise traps, flight intercept traps and sweep nets to sample in the vegetation. Additional information on distribution, biology and host-plants is provided for each species. Seven species are recorded for the first time from France: Craspedolepta artemisiae (Foerster, 1848), Craspedolepta nebulosa (Zetterstedt, 1828), Cacopsylla propinqua (Schaefer, 1949), Cyamophila prohaskai (Priesner, 1927), Eryngiofaga cf. refuga (Loginova, 1966), Bactericera parastriola Conci, Ossiannilsson & Tamanini, 1988 and Trioza flixiana Burckhardt & Lauterer, 2002. Trioza (Trioza) rapisardai Conci & Tamanini, 1984 is a new subjective synonym of Trioza brachyceraea Hodkinson & White, 1979, which was previously known only from the male holotype. The abundance, distribution and introduction status of some species are discussed. more...

Taxonomic checklist of the world’s whiteflies (Insecta: Hemiptera: Aleyrodidae)

The Neotropical genus Panisopelma (Psyllidae: Aphalaroidinae) is revised and its internal phylogeny analysed. The constituent species, including five new ones, are described and illustrated. Keys are provided for the adults and the last instar larvae. Eight species are associated with creosote bushes (Larrea, Zygophyllaceae): five with L. nitida and three with L. divaricata. There is evidence that another three species, the larvae of which are unknown, also develop on L. divaricata. Seven species are restricted to Argentina, one to Bolivia and three to Chile. The cladistic analysis based on male, female and larval morphological characters yielded a single most-parsimonious tree. The species associated with L. nitida form a monophyletic clade, those on L. divaricata, by contrast, are paraphyletic. One clade with three species is restricted to Argentina, but three clades each contain a species from Argentina and Chile. Although a close association exists between Panisopelma and Larrea, there is no evidence for cospeciation, but rather an initial shift from an unknown host to L. divaricata and a second shift from L. divaricata to L. nitida. In three species pairs of Panisopelma, the distribution patterns suggest geographical vicariance between Argentina and Chile. more...

A secondary structure model for 18S rRNA of peloridiids, relict insects with a present-day circumantarctic distribution, is constructed using comparative sequence analysis, thermodynamic folding, a consensus method using 18S rRNA models of other taxa, and support of helices based on compensatory substitutions. Results show that probable in vivo configuration of 18S rRNA is not predictable using current free-energy models to fold the entire molecule concurrently. This suggests that refinements in free-energy minimization algorithms are needed. Molecular phylogenetic datasets were created using 18S rRNA nucleotide alignments produced by CLUSTAL and rigorous interpretation of homologous position based on certain secondary substructures. Phylogenetic analysis of a hemipteran data matrix of 18S rDNA sequences placed peloridiids sister to Heteroptera. Resolution of affiliations between the three main euhemipteran lineages was unresolved. The peloridiid 18S RNA model presented here provides the most accurate template to date for aligning homologous nucleotides of hemipteran taxa. Using folded 18S rRNA to infer homology of character as morpho-molecular structures or nucleotides and scoring particular sites or substructures is discussed. more...

African members of the pantropical genus Diclidophlebia Crawford (Paurocephalinae) are revised. Sixteen species are recognised including three known species, seven new species and six species that are not formally described owing to insufficient material. Adult and last larval instars are diagnosed and illustrated and keys are provided for identification. Five species are associated with Sterculiaceae (Malvales) and one each with Tiliaceae (Malvales), Irvingiaceae/Simaroubaceae (Rutales), Chrysobalanaceae (Rosales) and Euphorbiaceae (Euphorbiales). Host plants of other species are unknown. Possibly monophyletic groups include four species restricted to the Guineo-Congolian region and five species in the Sudano-Zambezian region. Additional keywords: Afrotropical, Chrysobalanaceae, commercial timber, Diclidophlebia, Euphorbiaceae, Hemiptera, host-plant relationships, Irvingiaceae, new taxa, pest species, Simaroubaceae, Sterculiaceae, Tiliaceae. more...

A revised classification for the world jumping plant-lice (Hemiptera: Psylloidea) is presented comprising all published family and genus-group names. The new classification consists of eight families: Aphalaridae, Carsidaridae, Calophyidae, Homotomidae, Liviidae, Phacopteronidae, Psyllidae and Triozidae. The Aphalaridae, Liviidae and Psyllidae are redefined, 20 family-group names as well as 28 genus-group names are synonymised, and one replacement name is proposed [Sureaca nomen nov., for Acaerus Loginova, 1976]. Forty two new species combinations are proposed resulting from new genus-group synonymies and a replacement name. One subfamily and three genera are considered taxa incertae sedis, and one genus a nomen dubium. Finally eight unavailable names are listed ( one family-group and seven genus-group names). more...