26 research outputs found

    Taxonomic identification and biological traits of Platystethynium triclavatum (Donev & Huber, 2002), comb. n. (Hymenoptera, Mymaridae), a newly recorded egg parasitoid of the Italian endemic pest Barbitistes vicetinus (Orthoptera, Tettigoniidae)

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    The little known fairyfly (Hymenoptera, Mymaridae), Platystethynium (Platystethynium) triclavatum (Donev & Huber, 2002), comb. n. from Pseudocleruchus Donev & Huber, 2002, is newly recorded as an egg parasitoid of Barbitistes vicetinus Galvagni & Fontana, 1993 (Orthoptera, Tettigoniidae). This bush-cricket is endemic to northeastern Italy (mainly Euganean Hills of Veneto Region), where it has recently become an economically significant agricultural and forest pest. Data on discovery, distribution, and some remarkable biological traits of this gregarious egg parasitoid are presented. Its identification and availability of many well-preserved fresh specimens have made possible to re-define Pseudocleruchus Donev & Huber, 2002 syn. n., with type and the only described species Pseudocleruchus triclavatus Donev & Huber, 2002, as a synonym of Platystethynium Ogloblin, 1946 and its nominate subgenus, P. (Platystethynium), and also to describe the brachypterous male of P. (Platystethynium) triclavatum. It is the first known male for the entire genus. Enlarged mandibles of the megacephalous males are used to chew holes in the hard chorion of the host egg, allowing fully winged females, whose mandibles are strongly reduced and do not cross over, to emerge after mating with the males inside it. Up to 136 individual parasitoids (about 77 on average) can hatch from a single egg of B. vicetinus, with their sex ratio being strongly female biased (80–97% females per egg)

    A unique midgut-associated bacterial community hosted by the cave beetle \u3cem\u3eCansiliella servadeii\u3c/em\u3e (Coleoptera: Leptodirini) reveals parallel phylogenetic divergences from universal gut-specific ancestors

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    Background Cansiliella servadeii (Coleoptera) is an endemic troglobite living in deep carbonate caves in North-Eastern Italy. The beetle constantly moves and browses in its preferred habitat (consisting in flowing water and moonmilk, a soft speleothem colonized by microorganisms) self-preens to convey material from elytra, legs, and antennae towards the mouth. We investigated its inner and outer microbiota using microscopy and DNA-based approaches. Results Abundant microbial cell masses were observed on the external appendages. Cansiliella’s midgut is fully colonized by live microbes and culture-independent analyses yielded nearly 30 different 16S phylotypes that have no overlap with the community composition of the moonmilk. Many of the lineages, dominated by Gram positive groups, share very low similarity to database sequences. However for most cases, notwithstanding their very limited relatedness with existing records, phylotypes could be assigned to bacterial clades that had been retrieved from insect or other animals’ digestive traits. Conclusions Results suggest a history of remote separation from a common ancestor that harboured a set of gut-specific bacteria whose functions are supposedly critical for host physiology. The phylogenetic and coevolutionary implications of the parallel occurrences of these prokaryotic guilds appear to apply throughout a broad spectrum of animal diversity. Their persistence and conservation underlies a possibly critical role of precise bacterial assemblages in animal-bacteria interactions

    cave hygropetric beetles and their feeding behaviour a comparative study of cansiliella servadeii and hadesia asamo coleoptera leiodidae cholevinae leptodirini

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    Several Leptodirini beetles (Leiodidae) are known to dwell in hygropetric habitats where films of water run down the cave walls, but observations of their behaviour are lacking. The ultra- specialised hygropetricolous beetles belonging to the genera Cansiliella and Hadesia are biogeographically and phylogenetically unrelated leptodirines. As the species of the former genus are known to be associated with the moonmilk deposits our study aimed to obtain data on their foraging behaviour, as well as to compare the feeding strategies of both genera. In situ monitoring of C. servadeii from the cave Grotta della Foos (Italy) and H. asamo from Bravenik Cave (Bosnia and Herzegovina), was complemented by video recordings to ensure accurate results. Mouthparts and tarsi of both species were examined using scanning electron microscopy and compared with H. weiratheri from Montenegro to evaluate potential morphological adaptations to the hygropetricolous ecological niches. The three species had significantly different mouthpart morphologies, likely due to differences in semi-aquatic feeding strategies and overall ecology. A series of new observations on site movement and feeding behaviour are presented, compared and discussed. Key words: Coleoptera, ecology, behaviour, moonmilk, cave hygropetric. Primerjava jamskih higropetricnih hroscev in njihovegaprehranjevanja; Cansiliella servadeii in Hadesia asamo (Coleoptera, Leiodidae, Cholevinae, Leptodirini) Stevilni hrosci iz poddružine Leptodirinae (Leiodidae) so prilagojeni na življenje v posebnem habitatu »jamskem higropetriku «, t.j. tankem sloju tekoce vode, ki tece po sigi. Zaenkrat je njihovo vedenje se precejsnja neznanka. Visoko specializirani higropetricni vrsti Cansiliella servadeii in Hadesia asamo sta geografsko loceni in filogenetsko nesorodni. Ker je prva ocitno vezana na depozite mehke sige (t.i. jamsko mleko), smo želeli raziskati iskanje hrane pri tej vrsti ter primerjati strategijo hranjenja obeh vrst. Da bi povecali zanesljivost rezultatov, smo poleg in situ opazovanja C. servadeii iz jame Grotta della Foos (Italija) in H. asamo iz jame Bravenik (Bosna in Hercegovina), njuno vedenje tudi posneli. Z vrsticnim elektronskim mikroskopom smo raziskali obustne okoncine in stopalca obeh vrst in jih primerjali s H. weiratheri iz Crne gore, da bi preverili potencialne morfoloske prilagoditve na specificno ekolosko niso. Bistvene razlike v zgradbi ustnega aparata so najverjetneje posledica razlik v strategiji hranjenja, kot tudi razlicne splosne ekologije omenjenih vrst. V prispevku predstavljamo, primerjamo in razpravljamo o novih opažanjih povezanih z gibanjem in prehranjevanjem higropetricnih hroscev. Kljucne besede: Coleoptera, ekologija, vedenje, jamsko mleko, jamski higropetrik

    Cognitive vulnerability in mental disorders

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    ABSTRACT: Introduction: Modes of cognitive vulnerability were evaluated in outpatients of psychological services centers with diagnoses of mental disorders. Objective: To establish components of cognitive vulnerability in different mental disorders. Method: The participants were 490 users of psychological services centers from twelve universities in Colombia. To identify the presence or absence of mental disorders, they completed the MINI International Neuropsychiatric Interview.The Young Schemes Questionnaire, the Core Beliefs Questionnaire for Personality Disorders, the Inventory of Automatic Thoughts, and the Coping Strategies Questionnaire were also applied. To establish distinctive characteristics among actual major depression, generalized anxiety disorder, panic disorder, social anxiety, and non-alcoholic substance abuse, a logistic regression analysis was conducted. Results: The results showed cognitive distinctive vulnerability profiles, according to the disorder. Conclusion: The hypothesis of cognitive specificity for the different mental disorders is confirmed.RESUMEN: Introducción: Se evaluaron los modos de vulnerabilidad cognitiva en usuarios de consulta externa en psicología, diagnosticados con trastornos mentales. Objetivo: Establecer componentes de vulnerabilidad cognitiva en diferentes trastornos mentales. Método: Participaron 490 usuarios de servicios psicológicos de doce universidades de Colombia. Se aplicó la Entrevista Neuropsiquiátrica Internacional para identificar la presencia o no de trastornos mentales; igualmente, se aplicaron el Cuestionario de Esquemas de Young, el Cuestionario de Creencias Centrales de Trastornos de la Personalidad, el Inventario de Pensamientos Automáticos y el Cuestionario de Estrategias de Afrontamiento. Se realizaron análisis de regresión logística para establecer características distintivas en los trastornos de depresión mayor actual, ansiedad generalizada, angustia, ansiedad social y abuso de sustancias no alcohólicas. Resultados: Se reportaron perfiles cognitivos de vulnerabilidad diferenciados de acuerdo con el trastorno. Conclusión: Se confirma la hipótesis de especificidad cognitiva para los diferentes trastornos mentales

    Phylogenetic studies of tephritid flies (Diptera, Tephritidae) and their symbiotic bacteria

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    Tephritidae, commonly known as “fruit flies” is a large and complex family. Most, particularly the frugivorous species, are notorious pests. These include Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), Bactrocera oleae (Rossi) (olive fly), Rhagoletis cerasi (L.) (cherry fly), Rhagoletis completa (Cresson) (walnut husk fly) and other exotic species. Other species, however, live on the flower heads of Asteraceae. Since the beginning of the last century, some authors (Petri 1909, Stammer, 1929) report the presence of symbiotic bacteria in flies belonging to the subfamily Tephritinae. Recently the olive fly symbiont has been described and designated as ‘Candidatus Erwinia dacicola’ by (Capuzzo et al., 2005). The present work aims to study the relationships between species of the family Tephritidae and their symbiotic bacteria. It is based upon three main studies, the first of which has already been published. 1.- The first study is the continuation of Alessia Piscedda PhD. thesis and deals with the identity of symbiotic bacteria, in 25 flies belonging to the subfamily Tephritinae (Diptera: Tephritidae), which were collected mainly in northern Italy. In order to detect and identify symbiotic bacteria, the first tract of the midgut of flies emerging from previously sterilized pupae, was plated on different microbiological media, LIVE/DAD BacLight staining was performed and biomolecular techniques were used. According to Stammer, (1929) the presence of non culturable symbiotic bacteria has been detected in species of genera Tephritis, Campiglossa, Trupanea, Acanthiophilus, Sphenella, and Oxyna. Symbiotic bacteria have also been found in other genera (Capitites, Dioxyna, Noeeta), which were not studied by Stammer. Sequencing 1000 bp of the small subunit rDNA gene from these symbiotic bacteria has indicated that they belong to the family Enterobacteriaceae and a novel candidate organism has been proposed for the symbiotic bacteria of the genus Tephritis, under the designation ‘Candidatus Stammerula tephritidis’. These analyses have been extended to other tribes of the subfamily Tephritinae (Xyphosiini, Myopitini e Terellini), using the same techniques reported above, but non symbiotic bacteria have been detected in these tribes, as suggested by Stammer (1929). 2.- The second study of the present work analyzes the phylogenetic relationships between tephritid flies of the subfamily Tephritinae. Two regions of the mitochondrial DNA, 16S rDNA e COI-tRNALeu-COII, were examined. The phylogenetic trees obtained from a Bayesian Inference and a Maximum-Likelihood analysis have suggested, as a rule, the presence of five monophyletic clusters corresponding to the fives tribes of this subfamily: Tephritini, Myopitini, Xyphosiini, Noeetini e Terellini. The phylogenetic tree obtained from the analysis of the COI-tRNALeu-COII showed more highly resolved trees and the internal nodes more highly supported than the phylogeny inferred from the 16S data set, and defined the relationships among the tribes better. Cophylogenetic analysis has been carried out, and the presence of congruence between hosts and symbionts, even if imperfect, has been suggested. The reconstructions obtained showed two principal events. The most important and probably earliest event corresponds with the acquisition of symbiotic bacteria by the common ancestor of the tribe. The presence of non-strict congruence is probably due to other events such as losses, duplications and hostswitchings. Indeed, these bacteria are extracellular symbionts and some opportunities for host-switching occur during the biological cycle of the fly. In the larval stadium, for instance, bacteria are located in the intestinal caeca (Petri 1909; Stammer, 1929), without the protection of the peritrophic membrane and are thus, in contact with free living bacteria present in the intestinal lumen. The contemporaneous presence of different species in the same host plant could also be an opportunity for host-switching. Considering all of these aspects, the presence of congruence, even if not strict, results particularly interesting and a physiological compatibility between host and symbiont seems to appear. 3.- In the third part of my PhD. thesis, the phylogenetic analysis of insects has been extended to Paleartic species belonging to other subfamilies (Trypetinae e Dacinae). It has been based on the analysis of two regions of the mitochondrial DNA: 16S e COI-tRNALeu-COII. The availability of sequences of the 16S rDNA of several species in GenBank, has allowed extending this data set. These phylogenetic analysis still in progress, confirms the traditional classification based on a morphological approach but suggests also interesting relationships among the tribes. I have also attempted to associate the phylogeny obtained with morphological symbiotic arrangements and biological characteristics. Interestingly, it was pointed out that all the species of the subfamily Tephritinae that overwinter as adults, present symbiotic bacteria in the first tract of the midgut. The presence of these bacteria seems to be essential for the overwintering adults. Indeed, while the diet of larval stages includes relatively rich substrates such as flower tissue and seeds, glyciphagous adults have access to less resources. Thus the presence of bacteria could be more critical for their survival than that in the earlier stages.I tefritidi costituiscono un’importante famiglia di ditteri fitofagi molti dei quali rivestono un notevole interesse economico in quanto dannosi alle colture agrarie. Le specie di maggior importanza sono quelle che si riproducono a carico del frutto tra cui Ceratitis capitata (Wiedemann) (mosca mediterranea della frutta), Bactrocera oleae (Rossi) (olivo), Rhagoletis cerasi (L.) (ciliegia), Rhagoletis completa (Cresson) (noce) e altre specie esotiche. Altre specie invece, come quelle appartenenti alla sottofamiglia Tephritinae vivono soprattutto a carico dei capolini fiorali delle Composite (Asteraceae). Nella famiglia dei tefritidi sono presenti simbiosi batteriche note per alcune specie da quasi un secolo (Petri, 1909; Stammer, 1929). Recentemente, grazie alle tecniche biomolecolari, è stata identificata e sequenziata la specie batterica simbionte della mosca dell’olivo. Per tale simbionte, che è risultato appartenere alle Enterobacteriaceae è stato proposto il nome “Candidatus Erwinia dacicola”. Il presente lavoro ha come obiettivo l’approfondimento delle conoscenze sulle relazioni tra i ditteri tefritidi e i loro batteri simbionti e si articola in tre parti la prima delle quali è già stata oggetto di una pubblicazione. 1. In continuazione della tesi di dottorato della dottoressa Alessia Piscedda, l’identità dei batteri simbionti è stata studiata in 25 specie della sottofamiglia Tephritinae (Diptera: Tephritidae) provenienti da diverse zone del nordest d’Italia e da paesi limitrofi. Per queste specie si è provveduto alla coltivazione del contenuto del mesointestino di mosche provenienti da pupe preventivamente sterilizzate, all’osservazione di preparati microscopici di questo stesso tratto dell’intestino con LIVE/DAD BacLight e all’utilizzo di tecniche biomolecolari. In accordo con quanto riportato da Stammer (1929) le indagini hanno consentito di accertare la presenza di batteri simbionti non coltivabili in numerose specie dei generi: Tephritis, Campiglossa., Trupanea, Acanthiophilus, Sphenella, e Oxyna. Simbiosi batteriche sono state rinvenute anche in alcuni generi non considerati da Stammer (Capitites, Dioxyna, Noeeta). I batteri, di cui è stato sequenziato un frammento del 16S rDNA di oltre 1000 bp, risultano specifici per ogni specie di insetto ospite e, come il simbionte della mosca dell’olivo (Bactrocera oleae), appartengono tutti alla famiglia delle Enterobacteriaceae. I batteri simbionti riscontrati nelle specie del genere Tephritis per la loro affinità filogenetica sono stati designati come “Candidatus Stammerula tephritidis”. L’estensione dell’indagine ad altre tribù paleartiche della sottofamiglia Tephritinae (Xyphosiini, Myopitini e Terellini) con le medesime tecniche, sia tradizionali che biomolecolari, non ha evidenziato la presenza di batteri simbionti come suggerito da Stammer (1929). 2. Nella seconda parte del lavoro sono state studiate le relazioni filogenetiche tra i tefritidi, appartenenti alla sottofamiglia Tephritinae, analizzando due regioni del DNA mitocondriale, 16S rDNA e COI-LeutRNA-COII. Gli alberi filogenetici risultati da una analisi bayesiana e di maximum-likelihood hanno evidenziato la presenza di 5 cluster monofilettici e di regola altamente supportati corrispondenti alle 5 tribù della sottofamiglia Tephritinae: Tephritini, Myopitini, Xyphosiini, Noeetini e Terellini. La ricostruzione filogenetica ottenuta dal COI-tRNALeu-COII data set è risultata più risolta e supportata nei nodi interni rispetto a quella del 16S rDNA, contribuendo maggiormente a definire i rapporti di parentela tra le tribù. La disponibilità di una filogenesi dei batteri simbionti e dei loro insetti ospiti ha consentito inoltre lo studio della congruenza filogenetica. I diversi test di cofilogenesi addottati hanno evidenziato la presenza di una congruenza, seppur imperfetta, tra ospiti e simbionti. Dalle ricostruzioni si riconoscono due principali eventi di acquisizione il più importante e antico dei quali è quello avvenuto a carico dell’antenato comune della Tribù Tephritini. La causa di una non perfetta congruenza è da imputare all’esistenza di perdite, riacquisizioni e trasferimenti orizzontali. È importante ricordare che, essendo tali simbionti extracellulari, il ciclo biologico di questi insetti potenzialmente offre parecchie occasioni per trasferimenti orizzontali accidentali. Essendo nello stadio larvale i simbionti presenti nei cechi gastrici, parzialmente a contatto con il bolo alimentare, risulterebbero vulnerabili e sostituibili da altri batteri. Anche la frequentazione, da parte di specie diverse, delle stesse piante ospiti potrebbe essere occasione per trasferimenti orizzontali e sostituzioni. A fronte di queste molteplici possibilità la congruenza filogenetica riscontrata, seppure imperfetta, risulta a maggior ragione particolarmente interessante e va probabilmente spiegata con il coinvolgimento di altri fattori quali l’esistenza di una compatibilità fisiologica tra l’insetto ospite ed il battere. 3. Nella terza parte del lavoro l’analisi filogenetica degli insetti è stata ampliata a specie paleartiche appartenenti ad altre sottofamiglie (Trypetinae e Dacinae) sempre basandosi su due regione del DNA mitocondriale (16S e COI-LeutRNA-COII). La disponibilità in GenBank di sequenze del 16S di altre specie appartenenti a diverse regioni zoogeografiche ha consentito di allargare almeno per questo gene il data set. L’elaborazione dei dati, ancora parzialmente in corso, conferma in generale la tradizionale classificazione condotta su base morfologica ma offre anche spunti di discussione per eventuali riarrangiamenti di alcuni taxa. É stato realizzato anche un tentativo di affiancare alla ricostruzione filogenetica, oltre agli aspetti legati al ciclo biologico della specie, anche le diverse caratteristiche morfologiche degli organi adibiti ad ospitare i batteri simbionti nell’adulto. Risulta interessante notare come, tutte le specie paleartiche analizzate che svernano come adulti, ospitano batteri simbionti. Al contrario (tranne in un caso), tutte le specie che non svernano come adulto, sono risultate prive di batteri simbionti. Tali acquisizioni lasciano supporre che la presenza dei simbionti a livello del mesointestino, più che una opportunità per integrare la dieta larvale probabilmente già relativamente ricca, possano rappresentare, per quelle specie che hanno scelto di svernare allo stadio di adulto, una componente indispensabile

    Host instar influence on offspring sex ratio and female preference of Neodryinus typhlocybae (Ashmead) (Hymenoptera, Dryinidae) parasitoid of Metcalfa pruinosa (Say) (Homoptera, Flatidae)

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    The parasitoid wasp Neodryinus typhlocybae (Ashmead) was introduced to Europe for the biological control of nearctic planthopper Metcalfa pruinosa (Say), which causes severe damage to both crops and ornamental species in the absence of specialized natural enemies. We performed a series of experiments to evaluate the host instar preference and the effects on parasitoid offspring sex. Results showed that parasitism occurs mostly on 3rd, 4th and 5th host instars. Male parasitoid offspring were reared exclusively from 3rd instars. Both male and female offspring originated from the 4th instar, but the sex ratio remained male-biased. A greater proportion of female offspring originated from the 5th instar. Virgin mothers produced exclusively male progeny. When female wasps were exposed to an equal proportion of 3rd, 4th and 5th host instars, parasitism occurred predominantly on the 5th instar, while the least parasitized was the 3rd instar. The age of female wasps did not influence the preference for host instars or the offspring sex ratio. However, females previous experienced with small host instars resulted in a greater production of female offspring on the 5th instar, compared to females which had never encountered small instars. We discuss the relevance of these findings, which could provide new insights for the optimization of the mass rearing of this parasitoid wasp
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