1,721,066 research outputs found
Leucopis (Leucopomyia) alticeps Czerny (Diptera: Chamaemyiidae): nota preliminare sull'influenza dei fattori abiotici influenzanti lo sviluppo della specie
No full textAlcune note sull'allevamento di Opius concolor Szépl. (Hymenoptera Braconidae) e su recenti tentativi d'introduzione della specie in Toscana e Liguria.
No full textPrimo ritrovamento in Italia di Agathis fuscipennis (ZETTERSTEDT, 1838) (HYMENOPTERA: BRACONIDAE) su Tuta absoluta (Meyirick, 1917) (Lepidoptera: Gelechidae)
No full textIl Gelechide Tuta absoluta è un minatore fogliare legato a numerose Solanacee spontanee e coltivate, ma in grado di vivere anche a spese di alcune Leguminose. Originario del Sudamerica, dove è una delle specie più dannose per le colture di pomodoro, ha ormai da qualche anno colonizzato diverse regioni del continente europeo, dove si sta diffondendo in modo sempre più preoccupante, senza che ad oggi si siano individuati metodi di controllo efficaci. In questo contesto, assume particolare importanza la valutazione di tutti i fattori naturali di regolazione in grado di limitarne le popolazioni. Tra questi, fondamentale risulta l’individuazione di parassitoidi e/o predatori autoctoni capaci di evolversi a spese delle popolazioni di Tuta. Nel corso di un biennio di osservazioni condotte a Capezzano Pianore, in serre di pomodoro infestate dal Gelechide e nelle aree immediatamente prospicienti tali coltivazioni, Agathis fuscipennis, un Imenottero Braconide della sottofamiglia Agathidiini, è risultato essere il maggiore parassitoide endofago di T. absoluta. Gli esemplari sono emersi da larve prelevate su piante spontanee di Solanum nigrum. Nel periodo settembre-ottobre del 2009 e 2010 sono state isolate circa 1000 foglie con mine; da esse sono sfarfallati 304 adulti del Braconide su un totale di 1501 larve di Tuta, equivalenti ad una percentuale di parassitizzazione del 20. Il dato evidenzia un importante ruolo di questo entomofago, la cui larva è in grado di evolversi a spese di numerosi Lepidotteri, tra cui anche svariate specie appartenenti alla famiglia dei Gelechidi. Il suo vasto range di ospiti può dare una spiegazione del suo adattamento alla nuova specie di fitofag
Bioactivity of Essential Oils from Mediterranean Plants: Insecticidal Properties on Sitophilus zeamais and Effects on Seed Germination
No full textThe essential oils extracted from plants are potentially an interesting alternative to the chemical control of insect pests of stored grains. Goal of the study was the evaluation of bioactivity of essential oils extracted from four Mediterranean plants, Laurus nobilis, Citrus bergamia, Foeniculum vulgare and Lavandula hybrida. These compounds were assayed for their insecticidal effects on adult Sitophilus zeamais and their effect on the germination of corn and durum wheat seeds. Maize-weevil adults were bioassayed with both contact and fumigant protocols. Fennel and lavandin showed the highest insecticidal properties in contact and topical bioassays but bay laurel and lavandin were most active in inhalation bioassays. At the tested doses, all essential oils significantly inhibited seed germination compared to controls. According to the obtained results, some of the essential oils tested showed interesting insecticidal properties and their performances could be evaluated at a more refined step of evaluation
Insecticide resistance in Italian populations of Tribolium flour beetles
Full text linkAs a consequence of the widespread use of chemical insecticides in the control of insect pests in grain warehouses and in the food industry, insecticide resistance in grain insect pests has greatly increased all over the world. The goal of this work was to investigate insecticide resistance levels in Italian populations of Tribolium castaneum (Herbst) and Tribolium confusum du Val collected in grain and food storage facilities of 18 different localities. Six contact insecticides were tested on seven populations of the red flour beetle and on eleven populations of the confused flour beetle. Topical application bioassays were carried out on adults. Dose-mortality lines were estimated to determine the resistance ratios for each insecticide and population. A Principal Components Analysis (PCA) was performed on a data matrix describing the pattern of occurrence of the RR values of each insecticide across the set of data provided by 18 different sites. In both species, the slopes of LD-lines range within a rather narrow interval with respect to susceptible strains, while the highest RR value can be observed in a population of the confused flour beetle from Molise assayed with deltamethrin. The distribution of the experimental points in the PCA graph suggests that T. castaneum populations were generally more susceptible to malathion, diazinon and pirethrins than the T. confusum populations. RR values obtained in bioassays suggest that insecticide resistance is not a widespread problem in Italian strains of T. castaneum and T. confusum, but there are populations in which the phenomenon exists. An extended monitoring activity could, therefore, be crucially important in adopting proper control measures for pest management
The community composition of ladybirds (Coccinellidae) occurring in three vineyards in Tuscany (Italy)
No full textThe ladybird communities were investigated in three differently managed vineyards of the province of Pisa (Tuscany, Italy), two of which were organic. A total of 4,057 specimens were captured in 2012 and 866 in 2013, all belonging to the subfamilies of Scymninae, Coccinellinae, Coccidulinae and Chilocorinae. The ladybird community was analysed on the base of the simple species composition as well as of the trophic guild to whom they belonged. Scymninae and Coccinellinae were the most represented subfamilies. Aphidophagous components of the community were the highest everywhere, followed by the species feeding on coccids, fungi and mites. The analysis based on the community functional biodiversity was better in discriminating different vineyards then the one based on species diversity. The two organic vineyards showed a higher potentiality to host a high number of species and a complex community structure. Coccid predators were predominant in the conventional vineyard
Asobara tabida (Nees, 1834) (Hymenoptera Braconidae): prima segnalazione per l’Italia di questa specie a diffusione mondiale
No full textGli esemplari sono stati raccolti per la prima volta in Nord Italia, nella Provincia di trento, utilizzando trappole di plastica a caduta, provviste di fori multipli sulle pareti laterali, innescate con aceto di mele come attrattivo (Cini et al. 2012). Le trappole sono state collocate entro la superficie di un appezzamento per la coltivazione ad uso commerciale di mirtillo, Vaccinium corymbosum L., per valutare la densità di popolazione di Drosophila suzukii Matsumura (Diptera: Drosophilidae). A. tabida è un endoparassitoide, koinobionte, solitario, infeudato a molte specie del genere Drosophila spp. di cui la più nota è D. melanogaster (Vet et al. 1984). Questa
specie, estremamente invasiva, è originaria del sud-est asiatico e negli ultimi anni si è diffusa anche nei territori più occidentali. Nonostante la presenza di questo Braconide sia ampiamente documentata in molte regioni europee, nessun dato, ad oggi, era riportato riguardante la sua presenza in Italia (van Achteberg, 2004; Stoch, 2003-2004). La presenza di A. tabida in Italia, in simpatria con quella di D. suzukii potrebbe indicare un suo ruolo come agente di controllo biologico nei confronti di D. suzukii, che è diventata rapidamente un fitofago di estrema rilevanza economica
in numerosi agroecosistemi frutticoli europei (Cini et al. 2012). Una tale considerazione è supportata da ritrovamenti
di adulti A. tabida sfarfallati in Giappone da pupe di D. suzukii (Mitsui et al. 2007). Recenti esperimenti in condizioni di laboratorio non confermano però questa evidenza (Chabert et al. 2012
Leptoconops (Holoconops) kerteszi (Diptera Ceratopogonidae) in the coastal area of Grosseto: eco-ethological aspects
No full textMulti-year observations on the life-cycle of Leptoconops (Holoconops) kerteszi Kieffer (Diptera Ceratopogonidae) were carried
out in the coastal areas of Grosseto (Italy). In the studied environment, most of the populations complete two generations within a
year. Overwintering is assured by the larvae. Using a simple and functional sampling technique of preimaginal stages, we obtained
a general overview of L. (H.) kerteszi breeding sites. L. (H.) kerteszi is generally found in coastal swampy areas, where the
species colonizes a sandy shore that is devoid of vegetation and remains constantly damp as saltwater ascends by capillarity. Larvae
living in the first centimeter of the shallow sandy layer. Such sites occur in interdunal sandy areas bordering the ponds closest
to the seashore and also in tongues of sand along the edges of the ponds beyond the dunes, a little further inland
The genus Paragus Latreille (Diptera Syrphidae), a useful bioindicator in the vineyards.
No full textWe studied for two consecutive years the community structure of the Syrphid populations in three vineyards, observing the suitability of this family in discriminating the different sites. We also focused our attention on the community structure of the species belonging to the genus Paragus Latreille, which is the dominant taxon in the Hoverflies’ population. The community structure of the Paragus species complex was able to discriminate the different environmental situations, while all the Syrphid species complex did not it. Many species of Syrphids show a high flight ability, which allow them to cover vast areas, rapidly colonizing or recolonizing stressed habitats from surrounding, as well as from long distances and this probably explain the homogeneity among the population occurring in the three different vineyards. As far as we know, the species of the genus Paragus are associated to aphid populations living on roots and on wood plants, so that they are more strictly linked to structural vegetal components of the habitat
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