Search results for "volatile"

Impact of an invasive pest in local semiochemical networks

During the host location process, egg parasitoids rely on a series of chemical stimuli from the host/plant complex. In particular, in tritrophic systems consisting of plants, herbivorous stink bugs and their egg parasitoids, previous studies demonstrated that wasps are attracted by oviposition-induced plant volatiles (OIPVs). These compounds act as indirect plant defence mechanism allowing plants to recruit egg parasitoids, which are in general the most important natural enemies of stink bugs. Moreover, when wasps land on a plant, they can exploit chemical footprints left by male and female stink bugs walking on the leaves as indirect host-related cues, since chemicals lead them in an area …

Integrating natural enemies and semiochemicals in cultural control for an effective IPM

2012

Since their discovery, many semiochemicals (behavior modifying chemicals) have been identified and synthetized, and a number of techniques have been developed to use them in integrated pest management (IPM) programs against insect pests. In particular, the uses of semiochemicals in IPM to monitor insect pest populations and to interfere with their behavior preventing agricultural damage are widely adopted by the growers. In the same time, evidences that semiochemicals can also modify the behavior of insect natural enemies inspired researchers to explore the possibility to use semiochemicals to conserve and/or enhance the efficacy of natural enemies in cropping systems. However the use of se…

The Plant as a Habitat for Entomophagous Insects

2016

Populations of herbivorous insects are naturally consumed by other predacious or predatory insect species. These entomophagous insects are thus plant-dwelling organisms that use the plant for several vital functions and are affected by plant traits at the evolutionary, organism and population levels. Many entomophagous species are used for the biological control of insect pests worldwide. The aim of this chapter is to provide an exhaustive review of mechanisms underlying the interactions between plants and entomophagous insects, including those governing life history traits at the individual level, as well as those acting on population and community structure and dynamics. We detail how pro…

Single sensillum responses in Trissolcus basalis females to companion plant volatiles

2016

In food resources location and selection, parasitoid females spend considerable time examining the substrate with their antennae, where chemosensory, mechanosensory and thermo-hygroreceptive sensilla exist. Olfaction and perception of plant volatiles play a basic role in recognition of nutritional resources. For Trissolcus basalis, an egg parasitoid of the green stink bug Nezara viridula, previous electroantennography and behavioural experiments tested the parasitoid’s response to extracted headspace volatiles and a synthetic blend of buckwheat volatiles indicated that T. basalis females have sensitive and selective olfactory responses some major buckwheat, Fagopyrum esculentum, flower vola…

Semiochemical exploitation by two egg parasitoids,Trissolcus basalis and Trissolcus brochymenae (Hymenoptera: Scelionidae)

Chemo-orientation in egg parasitoids, a self-controlled movement in time and space, is led by volatile or substrate-borne chemicals distribution in the environment for purposes of locating host, food, mates and other resources. The perception of these chemical stimuli can be either from a distance by exploiting long-range infochemicals in the case of volatile chemoreception and/or upon contact with the cues when wasps are relatively close to the host in the case of contact chemo-reception by perceiving short-range infochemicals. In the present thesis, two different examples of chemo-orientation were treated. The first is an olfactory chemo-reception concerning Trissolcus basalis (Wollaston)…

Modifications over time of volatile compounds in coriander (Coriandrum sativum L.)

2007

Coriander (Coriandrum sativum L.) is an annual strongly-smelling herb belonging to the family Apiaceae, which is cultivated all over the world for its aromatic fruits (“seeds”) and, in many Asiatic and South American countries, for its green leaves. The aromatic features of leaves and fruits are sharply different, and the strong smell coming from leaves (many times referred to as a “bug” scent) is not always pleasant to many consumers from western countries. In our work, one Coriander small-seeded biotype has been grown in plastic covered greenhouses, and at given time intervals samples of leaves, flowers and fruits have been analyzed by means of HS-SPME and GC-MS to study the evolution ove…

Variations in the volatile compounds of a Fennel (Foeniculum vulgare Mill.) variety grown in a semi-arid Mediterranean environment

2005

Fennel is an industrial source of anethole but, recently, further interest has came from the suggested possibility of many industrial uses of this plant. The volatile substances from the seeds of fennel grown in Sparacia (Cammarata - AG - Sicily; 37° 38' N; 13° 46' E) have been investigated and compared on a statistical base with previously reported data. The variety grown in Sparacia fall into the "high fenchone" chemovariety. The substances alpha-toluene, alpha-terpinene, beta-phellandrene + limonene and camphene appear the components most sensitive to environment and grow condition modifications. Fennel is an industrial source of anethole but, recently, further interest has come from the…

Characterization of Phenolic and Volatile Compounds of Sicilian Virgin Olive Oils Produced from Native Cultivars

2009

Compositions and Sensory Characterization of Olive Oils from CentralWestern Sicily

In Sicily, olive has been cultivated since ancient times and its germplasm is characterized by a wide genetic diversity that could be related to its domestication and spread in ancient times, and to some reproductive biological peculiarities as self-incompatibility. In this research, EVOO of Sicilian heritage such as Nocellara del Belice, Biancolilla, Biancolilla centinara and Passulunara, was been investigated. The assessment regards main chemical-physical parameters and sensory profles, based on the olfactory and gustatory characteristics. Samples were obtained from Bona Furtuna farm (Corleone, C-W Sicily), equipped with a continuous two and half phases cold extraction system. Results sho…

Influence of Citrus Essential Oils on the Microbiological, Physicochemical and Antioxidant Properties of Primosale Cheese

2022

The aim of this study was to produce a fresh ovine pressed cheese within Pecorino “Primosale” typology with the addition of citrus essential oils (EOs). For this purpose, ewe’s pasteurized milk was added with EOs from the peel of lemons, oranges and tangerines. Seven cheese productions were performed at the pilot plant scale level, including one control production (CP) without the addition of EOs and six experimental productions obtained by the addition of two EO concentrations (100 and 200 µL/L) to milk. The acidification process was obtained by means of the starter cultures Lactococcus lactis CAG4 and PON36. All cheeses showed levels of lactic acid bacteria (LAB) a…