THE PRESENT PEST STATUS OF EUCALYPTUS SAP-SUCKERS AND GALL WASPS IN CAMPANIA (ITALY)

Sap-suckers and gall wasps may be a severe phytosanitary problem for several Eucalyptus species, particularly for the red gum E. camaldulensis, the most widely cultivated Australian native tree species worldwide. This paper reviewed the harmfulness of some of these invasive pests established in Campania, and provides new information about their pest status

Aleurocanthus spiniferus, an alien invasive threat to Europe. AssociatEd bacterial community and natural enemies

Aleurocanthus spiniferus also known as orange spiny whitefly (OSW), is a pest native to tropical Asia that in the last century has spread throughout Asia, reaching Africa, Australia, and Pacific islands. In 2008 the first European OSW population was recorded in Apulia region (South East Italy) and allowed EPPO to add the species as a quarantine threat to Europe now in the A2 list. In the following years OSW spread and invaded new territories of Italy, Croatia and Montenegro. Although OSW polyphagy is already well-known, new associations with autochthonous and allochthonous plants have been reported showing its host-shifting ability. To counteract an upcoming pan-Mediterranean invasion updated bio-ethological information of the pest and the role of possible natural enemies are essential to implement a correct IPM strategy. Field samplings have been aimed at the identification of natural enemies and the evaluation of their efficacy. Furthermore, through insect small-RNA sequencing and by Denaturing Gradient Gel Electrophoresis (DGGE) technique coupled with 16S-rRNA gene sequencing, the primary symbiotic bacteria of OSW have been identified. Sampling on natural enemies highlighted the presence of predatory species belonging to the Coccinellidae family. Besides to the almost ineffective populations of Oenopia conglobata and Clithostetus arcuatus, new findings detected scattered Delphastus sp. populations along the western coast of Italy. Both adult and larvae of this ladybird species preyed OSW developmental stages. The evaluation of the role of Delphastus sp. as biocontrol agent is underway. The first study on OSW microbiota allowed to find symbiotic bacteria commonly associated with the genus Aleurocanthus: Portiera sp., Serratia sp., Wolbachia sp., Rickettsia sp. and, although sporadically, other species. Further studies will target the functional role of these symbionts to develop an effective IPM tailored for Countries at risk

An integrative revision of the subgenus Liophloeodes (Coleoptera: Curculionidae: Entiminae: Polydrusini) : taxonomic, systematic, biogeographic and evolutionary insights

The subgenus Liophloeus Weise, 1894 of Liophloeus Germar, 1817 (Coleoptera: Curculionidae: Entiminae: Polydrusini) consists of five morphologically similar species traditionally diagnosed based on the shape of the aedeagus. However, traits of the genital apparatus exhibit substantial and overlapping inter- and intraspecific variation. All five species have the same ecological requirements and occur in central and eastern Europe, mostly in montane areas. The focus of this work was to verify the taxonomic status and validity of Liophloeodes species using a combination of molecular and morphometric techniques. Specimens were collected from the entire distribution range and initially assigned to a species according to the aedeagal shape. Genetic diversity and phylogeny of the subgenus were studied using three molecular markers (two ribosomal, 28S-D2 and ITS2, and one mitochondrial, COI). Moreover, several morphological characters were used for multivariate morphometric analyses. Finally, presence and prevalence of bacterial endosymbionts among species were investigated. Phylogenies based on ribosomal markers suggest that traditional species are correctly delimited, whereas COI phylogeny suggests hybridization and introgression occurring between Liophloeodes species. Morphometric analyses confirmed low interspecific diversity. Two major bacterial endosymbionts, Rickettsia and Wolbachia, were detected in many populations. We argue that Liophloeodes consists of young lineages whose evolution and diversification was possibly mediated by cyclic climate change events

The Aleurocanthus spiniferus (OSW) in Europe: a becoming invasive threat to citrus also.

The orange spiny whitefly (OSW), Aleurocanthus spiniferus, is a worldwide known citrus pest native to tropical Asia. Since the beginning of the 20th century, OSW spread throughout Asia, the Pacific, central and Southern Africa and from 2008 it was intercepted many times in EPPO area (Italy, Croatia and Montenegro). OSW polyphagy is well known, being able to infest more than 90 host plants belonging to unrelated botanical families, although Citrus spp. are considered the primary hosts. Accurate samplings highlighted OSW new host associations extending the range of plant families potentially exploitable and confirming the existence of host-shift phenomena. Analyses of the mitochondrial COI gene revealed that OSW Apulian population belongs solely to one of the two haplogroups present in China. Furthermore, the study of microbiota allowed us to identify the principal endosymbiotic bacteria in OSW. So far, field samplings confirmed the presence of predators belonging to Coccinellidae family able to prey on different evelopmental stages of A. spiniferus. These findings could be considered as an opportunity for biological control of OSW. Results laid solid foundations in the knowledge of European OSW populations now invading Italy and neighbouring countries to counteract a pan-Mediterranean invasion of this harmful whitefly. Further studies are essential for the assessment of an effective IPM strategy tailored either for organic or intensive agricultural context

THE PRESENT PEST STATUS OF EUCALYPTUSSAP-SUCKERS AND GALL WASPS IN CAMPANIA (ITALY)

ap-suckers and gall wasps may be a severe phytosanitary problem for several Eucalyptusspecies, particularlyfor the red gum E. camaldulensis, the most widely cultivated Australian native tree species worldwide. This paperreviewed the harmfulness of some of these invasive pests established in Campania, and provides new information abouttheir pest statu

Genetic diversity of the invasive gall wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia endosymbiont, and associated sex-ratio differences

The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localised in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed. Nugne

Rapid Detection of Pityophthorus juglandis (Blackman) (Coleoptera, Curculionidae) with the Loop-Mediated Isothermal Amplification (LAMP) Method

The walnut twig beetle Pityophthorus juglandis is a phloem-boring bark beetle responsible, in association with the ascomycete Geosmithia morbida, for the Thousand Cankers Disease (TCD) of walnut trees. The recent finding of TCD in Europe prompted the development of effective diagnostic protocols for the early detection of members of this insect/fungus complex. Here we report the development of a highly efficient, low-cost, and rapid method for detecting the beetle, or even just its biological traces, from environmental samples: the loop-mediated isothermal amplification (LAMP) assay. The method, designed on the 28S ribosomal RNA gene, showed high specificity and sensitivity, with no cross reactivity to other bark beetles and wood-boring insects. The test was successful even with very small amounts of the target insect’s nucleic acid, with limit values of 0.64 pg/µL and 3.2 pg/µL for WTB adults and frass, respectively. A comparison of the method (both in real time and visual) with conventional PCR did not display significant differences in terms of LoD. This LAMP protocol will enable quick, low-cost, and early detection of P. juglandis in areas with new infestations and for phytosanitary inspections at vulnerable sites (e.g., seaports, airports, loading stations, storage facilities, and wood processing companies)

Caratterizzazione morfo-bio-molecolare di Anagrus Haliday (Hymenoptera: Mymaridae) parassitoidi di uova di cicaline

Negli ultimi anni si è assistito allo sviluppo ed all’applicazione dei metodi molecolari per la discriminazione specifica che ha permesso di caratterizzare molte specie di imenotteri laddove studi tassonomici classici avevano fallito. I dati molecolari, in particolare se integrati con dati di tipo morfologico, biologico ed ecologico, possono risultare decisivi nella discriminazione a livello specifico. A consolidare lo studio biosistematico, spesso a tali dati si accosta lo studio degli endosimbionti. Il genere Anagrus Haliday (Hymenoptera: Mymaridae) comprende ooparassitoidi di cicaline e altri omotteri, alcuni dei quali impiegati in programmi di controllo biologico in diversi agroecosistemi. Lo studio e la classificazione tradizionale, basata sui caratteri morfologici, delle specie di Anagrus appartenenti al gruppo atomus sono molto difficoltosi a causa della convergenza dei caratteri e la frequente riduzione o perdita di elementi discriminanti. Pertanto la revisione delle specie afferenti a tale genere è tuttora in atto su scala mondiale. Il presente lavoro dimostra l’efficacia dell’approccio integrato nella discriminazione delle specie del gruppo atomus. Sono stati indagati i rapporti intercorrenti tra 3 popolazioni di Anagrus del gruppo atomus appartenenti a differenti sistemi pianta - cicalina ospite - parassitoide : 1.Salvia sp. - Eupterix decemnotata - A. atomus; 2.Mentha sp. – E. zelleri – A. ustulatus e 3.Quercus ilex – Lindbergina aurovittata - A. ustulatus. L’approccio molecolare ha previsto l’individuazione di marcatori specifici tramite la tecnica dell’Intersimple Sequence Repeat (ISSR-PCR) e l’analisi di tratti di DNA ribosomale (28S-D2 e ITS2) e mitocondriale (COI). Dal sequenziamento di tali regioni e l’implementazione in programmi di filogenetica, la popolazione parassitoide di L. aurovittata è stata discriminata rispetto alle altre due popolazioni, risultate invece monofiletiche. Tali risultati sono stati confermati anche dall’analisi ISSR. Tramite la tecnica della DGGE e l’MLST System, si è proceduti all’identificazione e alla caratterizzazione di colonie batteriche endosimbionti associati alle specie di Anagrus indagate. Tali analisi hanno messo in evidenza la presenza dell’endosimbionte Wolbachia appartenente al supergruppo B nella popolazione del mimaride infeudata alla Lindbergina. Pertanto la presenza di soli individui femminili fa ipotizzare una probabile manipolazione della riproduzione ad opera di Wolbachia. dall’analisi morfometrica effettuata, il rapporto lunghezza ovopositore/lunghezza protibia, permette di distinguere la popolazione di Anagrus proveniente da Q. ilex rispetto alle altre due, le quali hanno mostrato una forte sovrapposizione nei caratteri morfologici considerati. Contrariamente a quanto emerso dagli studi morfo-molecolari, i crossing test, effettuati sulle popolazioni provenienti da Mentha e Salvia, ne hanno confermato l’isolamento riproduttivo in quanto non si sono verificati accoppiamenti incrociati tra individui di sesso opposto provenienti dai suddetti sistemi. Infine, i campionamenti e monitoraggi effettuati in lecceta, hanno evidenziato che la popolazione di Anagrus parassitoide di Lindbergina presenta una biologia particolare. Infatti durante il periodo estivo autunnale, quando la cicalina non è presente sulla pianta ospite, il parassitoide arresta il suo sviluppo allo stadio larvale intermedio, ritardando lo sfarfallamento degli adulti all’inizio dell’inverno in concomitanza con il ritorno dell’ospite. Quindi, sulla base dei dati morfometrici, biologici e molecolari, A. ustulatus vincolato alla cicalina L. aurovittata su Q. ilex è da ritenere una specie distinta dall’A. ustulatus sensu Chiappini (1989)

Arithmetical and set-theoretical determinacy: skeptical arguments on reference in mathematics

The work addresses the question ‘how do we fix the meaning of mathematical terms?’ by considering the cases of arithmetic and set theory. The point of departure is the basic consideration that we seem to be talking about numbers and sets as if they were sharp and definite concepts. By just looking at our best means to capture these notions, namely the mathematical theories of PA and ZFC, we encounter the disquieting phenomenon of nonstandard models. The same mathematical machinery that allows the construction of these models and the fact that set-theoretic semantics is itself set-theoretic historically gave rise to further skeptical doubts about the determinacy of reference in mathematics. The best-known way to secure determinacy for arithmetic is through second-order logic, but I argue that for our interests it does not fair better off than set theory. For set theory itself, on the other hand, there is no immediate solution to the problem. I survey the main proposals in the literature and conclude that none of them achieves what it sets out to do. Once radical skepticism is ruled out by epistemic considerations about the use of mathematical languages, I conclude that a moderate degree of indeterminacy is to be accepted in both arithmetic and set theory and that the request for absolute determinacy is to be abandoned as the last remnant of foundationalism

Chromosomes of Eupristina verticillata Waterston, 1921 and an overview of known karyotypes of chalcid wasps of the family Agaonidae (Hymenoptera)

The karyotype of Eupristina verticillata Waterston, 1921 (Agaonidae) from Italy was studied for the first time using chromosome morphometrics. The present study showed that this species has n = 6 and 2n = 12, with five larger metacentrics and a smaller acrocentric chromosome in the haploid set. A brief overview of known karyotypes of chalcid wasps of the Agaonidae is given; certain features of karyotype evolution of this family are discussed