Search results for " Entomologia"

Leaf epicuticular waxes effects egg parasitoid’s response to host adult footprint contact kairomone

2009

Chemical footprints left behind by true bugs are perceived as a contact kairomones by scelionid egg parasitoids. In the system Nezara viridula and its egg parasitoid Trissolcus basalis, previous studies have shown that the kairomone mediating such behavior is part of N. viridula’s cuticular hydrocarbons. In this study, the effect of epicuticular waxes of leaves of broad bean, Vicia faba, on wasp response to footprints of N. viridula females are investigated. Plants with intact waxes layer were used (1) without host chemical contamination, or (2) contaminated by host female footprints. Mechanically de-waxed plants were tested (3) without host chemical contamination, or (4) de-waxed a few min…

Plant surface mediates interaction between true bug chemical footprints and scelionid egg parasitoids

2009

Chemical footprints left behind by true bugs act as contact kairomones inducing an arrestment response in scelionid egg parasitoids. Once in contact with contaminated substrates, female wasps display a characteristic arrestment posture followed by an increase of the host searching time. Previous studies were conducted on artificial substrates as filter papers, so that little is known about the effects of natural substrates on behavioural response by wasps. In field, the substrate where these interactions occur, i.e. the surface of plants, is covered by wax layers that can have a role in trophic interactions between insects. In this study, we investigated the influence of plant surfaces on a…

I semiochimici utilizzati nella localizzazione dell’ospite da parte del parassitoide oofago Ooencyrtus telenomicida

2009

Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae) è un parassitoide oofago di Nezara viridula (L.) (Heteroptera: Pentatomidae) di origine paleartica frequentemente diffuso in Sicilia. Scopo del presente lavoro è stato quello di investigare il processo di localizzazione dell’ospite nel sistema tritrofico Solanum lycopersicum L. – N. viridula – O. telenomicida. In particolare sono stati condotti esperimenti in olfattometro a Y, per valutare il ruolo attrattivo dei composti volatili emessi sia dalle piante, sia dagli adulti della cimice verde, e in arena aperta, per biosaggiare. la risposta delle femmine del parassitoide alle tracce lasciate sul substrato dagli adulti di N. viridul…

Night surveys and smell, a mixed method to detect colonies of storm petrel Hydrobates pelagicus

2012

Storm-petrels usually breed in sites difficult to access, making it hard to estimate the number of individuals in a colony or even the presence of a colony. After several years of study in the main colony and diurnal surveys to other caves of the island, we planned an extensive night survey for identifying previously unknown colonies. In the breeding season of 2011 we found 5 new colonies of storm petrels (Hydrobates pelagicus) at Marettimo island, increasing the estimation of the population on this island to approximately 3000 breeding pairs. We propose the use of mixed methods to locate new colonies, as they can be found by the characteristic smell of storm petrels, but under windy condit…

Quanta infestazione di mosca possiamo tollerare?

2022

In questo articolo sono riportati i sorprendenti risultati dei pochi recenti articoli scientifici che indicano la soglia di tolleranza della mosca delle olive per l'ottenimento di olio. In caso di raccolte precoci e medie, con estrazione entro le 24 ore, si possono ottenere oli extravergini d'altà qualità anche con 43-44% di fori d'uscita di Bactrocera oleae This article reports the surprising results of the few recent scientific papers that indicate the tolerance threshold of olive fly for obtaining oil. In case of early and medium harvests, with extraction within 24 hours, high quality extra virgin olive oils can be obtained even with 43-44% exit holes of Bactrocera oleae

Il controllo degli insetti fitofagi nell'olivicoltura biologica.

2016

Puntuali strategie di controllo, campionamenti personalizzati e maggiore consapevolezza entomologica, insita nell’approccio del coltivatore biologico, consentono ottimi risultati quali-quantitativi ed economici nella difesa fitosanitaria in olivicoltura “organica” e in qualsiasi area olivicola italiana. Le minori spese fitosanitarie rispetto all’olivicoltura convenzionale inducono un sempre maggior numero di produttori alla conversione verso il bio. Gli autori illustrano le metodologie ammesse e consigliabili in regime di agricoltura biologica, per il controllo dei principali insetti fitofagi del olivo nel Mediterraneo, con particolare riferimento alla mosca delle oilve, Bactrocera oleae, e…

Studio del controllo di Bactrocera oleae, di funghi agenti filloptosi e carpoptosi anticipata nell’olivicoltura da mensa e da olio in Sicilia.

2010

Abstract STUDY ON THE CONTROL OF BACTROCERA OLEAE AND FUNGI INDUCING EARLY LEAF AND FRUIT DROP IN OLIVE GROWING FOR TABLE OLIVES AND OIL PRODUCTION IN SICILY. Susceptibility of olive cultivars to olive fruit fly, damage thresholds, sampling methods, effectiveness of products deterring olive fruit fly oviposition, foliar chlorosis and withering of branches have been investigated. Riassunto Tra le cultivar saggiate (16 siciliane e 6 estere) esiste un ampio gradiente nella suscettibilità agli attacchi di B. oleae, andando dalle più suscettibili Nocellara del Belice, Giarraffa, Cerasuola alle meno preferite; tra queste ultime vi sono cultivar con caratteristiche peculiari diversificate: Nocella…

ORTHOPTERA RACCOLTI IN TUNISIA NEL XIX SECOLO E CONSERVATI NEL MUSEO CIVICO DI STORIA NATURALE “G. DORIA” DI GENOVA.

1998

From non-target risk assessment to Bt resistance management: the example of Bt Brassica sp. and Pieridae

2011

Insecticidal toxins produced by Bacillus thuringiensis (Bt) have been widely used in plant protection in two different ways: 1) by spraying bacterial Bt formulations, 2) by expressing their gene encoding in planta. In the second strategy, only the transgenic plants themselves are protected but insect- resistant plants could spread into natural habitats and/or the gene could be fixed in alternative hosts. It is necessary to estimate the magnitude of the possible effects on naturally occurring herbivorous insects but also on the target species, especially when they have several alternative hosts, as in the case of Pieridae. They are present both in agriculture where they could be considered p…

Role of VOCs from Brassica oleracea in host location processes of Bagrada hilaris: electrophysiological and behavioral studies

2017

The Painted bug, Bagrada hilaris Burmeister is an herbivorous insect native of Asia and Africa, invasive in Southern Europe and North America where it causes major damage on various vegetable crops mainly belonging to Brassicaceae family. Young plants at cotyledon stage of B. oleracea are particularly attractant and susceptible to B. hilaris feeding activity. To elucidate the main volatile organic compounds (VOCs) involved in the attraction of B. hilaris individuals toward the host plant B. oleracea, laboratory experiments were carried out using vertical Y-shaped olfactometer and electroantennographic techniques (EAG). Both adults and late nymphal instars were used in these experiments. Olf…