Search results for " Entomologia"

Effect of dual biotic stress on plant volatile synomones used by egg parasitoids

2014

Studies on semiochemical communication have demonstrated that broad bean plant, Vicia faba, emits volatile synomones induced by feeding and oviposition activities of the southern green stink bug, Nezara viridula, which recruit the egg parasitoid Trissolcus basalis. However plants growing in agro-ecosystems can be attacked by several herbivore species that could affect both above and belowground plant tissues with possible consequences for parasitoid recruitment. For example, broad bean plants can also be attacked by the leaf weevil, Sitona lineatus, and simultaneous attacks by the southern green stink bug and the leaf weevil can occur in agro- ecosystems. The purpose of this work was to inv…

A sex pheromone triggers courtship behaviour in the egg parasitoid Trissolcus brochymenae

2010

Climate change impact on extrinsic and intrinsic competition between egg parasitoids

2012

Climate changing is a real phenomenon and the last decade was the warmest decade ever. The impact of climate change on animal communities is complex, affecting species interactions in all trophic levels, in different ways and in different bio-geographic zones. Here we will discuss about the possible effects of climate changes in shaping the competition between egg parasitoid species to consume the same hosts. Egg parasitoids are important biological control agents due to their ability to kill the pest before the crop-feeding stages emerge. Competitive effects can be divided in “extrinsic competition”, the indirect interactions between adult females searching for hosts, and “intrinsic compet…

Primi risultati sull'efficacia dell'olio minerale e dello spinosad nella lotta a Cydia funebrana in un susineto biologico siciliano

2011

Cydia funebrana (Treitschke) è considerato il fitofago chiave del susineto, soprattutto sulle cultivar cino-giapponesi a maturazione tardiva e nell’agricoltura biologica, a causa della mancanza di prodotti citotropici e ovicidi. Nel 2010 sono state effettuate prove per il contenimento del tortricide per valutare l’efficacia dello Spinosad e dell’olio minerale come prodotto anti-ovideponente. Le prove sono state svolte in un susineto biologico di San Giuseppe Jato (Palermo), di oltre 5 ha, su piante delle cultivar Angeleno, Friar e Stanley. Per ciascuna di esse sono state individuate tre parcelle di 50 piante, marcando al loro interno 10 piante su cui effettuare i rilevamenti; due parcelle s…

Il controllo biologico ed integrato

2005

A taxonomic revision of western Eupholidoptera bush crickets (Orthoptera: Tettigoniidae): testing the discrimination power of DNA barcode.

2014

The genus Eupholidoptera includes 46 Mediterranean species distributed from Turkey to Greece, Italy and southern France. In the eastern part of its range, Eupholidoptera has been considered to consist of several distinct species, while in the Balkans and Italian peninsula only E. chabrieri has been recognized. However, the status of some Italian populations, confined to particular geographic areas, remains uncertain. To investigate the delimitation of the Italian taxa of Eupholidoptera, we performed both morphological and molecular analyses. Morphological analysis was carried out by considering diagnostic characters usually used to distinguish different taxa, such as the shape of titillator…

Ground-level predation on artificial caterpillars indicates no enemy-free time for lepidopteran larvae

2017

Lepidoptera is one of the most diverse orders of insects, their larvae are very abundant in many habitats, and frequent prey of various predators. To decrease predation risk, caterpillars developed several means of defence, among them timing their activity to avoid predators (seeking enemy-free time). Although the enemy-free time hypothesis is often invoked to explain caterpillar behaviour, empirical evidence for it is scarce. We tested whether such enemy-free time exists in a temperate forest by comparing predation pressure on artificial caterpillars during day and night on the ground in forest fragments in Denmark. We found a high predation rate, 23.9% d(-1), and higher predation rate at …

Response to Kruse-Plass et al. (2017) regarding the risk to non-target lepidopteran larvae exposed to pollen from one or more of three Bt maize event…

2017

We respond to the paper of Kruse-Plass et al. (Environ Sci Eur 29:12, 2017), published in this journal, regarding the risk to non-target lepidopteran larvae exposed to pollen from one or more of three Bt maize events (MON810, Bt11 and 1507). We emphasise that what is important for environmental risk assessment is not the number of pollen grains per se, but the degree of exposure of a NT lepidopteran larva to Bt protein contained in maize pollen. The main text of this response deals with general issues which Kruse-Plass et al. have failed to understand; more detailed refutations of each of their claims are given in Additional file 1. Valid environmental risk assessment requires direct measur…

Essential oils composition of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae – Periplocoideae)

2012

The essential oil of roots, branches, leaves, flowers and fruits of Periploca laevigata Aiton subsp. angustifolia (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analysed. The analyses allowed the identification and quantification of 86 volatile compounds. Branches showed the higher diversity with 57 compounds followed by fruits with 33, roots with 23, flowers with 16 and leaves with six compounds, respectively. In the matrices examined three constituents, heneicosane, docosane and tricosane are in common, although with different percentages. At least the most abundant compounds found in the matrices have been reported to have several biologica…

Dimethyl disulfide and dimethyl trisulfide: so similar yet so different in evoking biological responses in saprophilous flies

2014

Dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) are used by saprophilous insects to locate breeding sites (decaying organic matter), and by brood-site deceptive flowers to attract such insects. However, little is known about the relative importance of these two compounds in eliciting electrophysiological and behavioral responses in the insects. Here, we compared the relative attractiveness of DMDS and DMTS to saprophilous flies in field choice experiments and tested whether potential differences in field responses can be explained by differences in electrophysiological antennal responses to these compounds. Field experiments revealed that the attractiveness of a mixture of these co…