Search results for " Parasitoids"

Bactrocera oleae. Fattori naturali di controllo

2019

Bactrocera oleae. Natural control factors. Natural control factors (parasitoids and climatic factors) influencing the olive fruit fly, Bactrocera oleae, are analysed comparing two different areas of cultivated and wild olives, Sicily and the Western Cape of South Africa. Bactrocera oleae has a similar level of parasitization in both areas, much higher in wild olives than in cultivated ones. Climatic conditions are much more important than climatic factors, influencing the growth of olive fruit fly populations, producing a higher level of infestation in more humid and rainy productive seasons.

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

Plants respond to arthropod herbivory with the induction of volatiles called herbivore-induced plant volatiles (HIPVs). These volatiles appear to be important sources of information that attract parasitoids. Parasitic wasps foraging decisions are often affected by community characteristics such as community diversity and complexity. As part of a complex habitat, the presence of unsuitable hosts (non-host) may affect foraging behavior of parasitoids. In this chapter, we outline the importance of the presence of unsuitable herbivores on the behavioral responses of parasitoids. First we review the foraging behavior of parasitoid in tritrophic interaction. Then we focus on foraging behavior by …

Learning can be detrimental for a parasitic wasp

2021

Animals have evolved the capacity to learn, and the conventional view is that learning allows individuals to improve foraging decisions. The parasitoid Telenomus podisi has been shown to parasitize eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of its coevolved host, Podisus maculiventris, but the parasitoid cannot complete its development in the exotic species. We hypothesized that T. podisi learns to exploit cues from this non-coevolved species, thereby increasing unsuccessful parasitism rates. We conducted bioassays to compare the responses of naïve vs. experienced parasitoids on chemical footprints left by one of the two host species. Both naïve and experienced …

The effect of distance between parasitoid and host on the parasitism of Psyttalia concolor (Szépligeti) in organic olive orchards

2013

Bactrocera oleae (Rossi) is a major pest of olive fruits. Biological control of olive fruit fly mainly relies on the activity of the Braconid species Psyttalia concolor (Szépligeti), which parasitizes Bactrocera oleae at the larval stage. Parasitism tests have been carried out at the insect growing facility (insectariums) of the Mediterranean Agronomic Institute of Bari (C.I.H.E.A.M.). The critical point of the use of P. concolor as a biological control agent in organic olive crop is the assessment of its effectiveness against B. oleae. Its lower presence in fruits of cultivated olives rather than in small fruits of wild olives suggests an influence of the size of the fruit, and of the thic…

The biological control applied in Citrus orchards against harmful exotic pests in Sicily (Italy)

2018

The citrus groves are injured by infestations caused by indigenous species or old and new phytophagous introduced. Several problems have found in the biological control a optimal solution that allowed a considerable reduction in the use of chemical products. In fact, applications of programs using biological methods has been more successful on citrus than in any other cropping system. Sicily (Italy), due to its location in the Mediterranean Sea, represents an island particularly rich flora and fauna with a characteristic biodiversity different from those of other countries and regions of Italy. It produces about 60% of the national citrus production with more areas of organic citrus groves.…

Chemical Ecology of Insect Parasitoids

2013

Effetti collaterali di una miscela a base di azadiractina ed oli minerale paraffinico sui parassitoidi di Phyllocnistis citrella Stainton (Lep.: Grac…

2000

Plant responses induced by Halyomorpha halys (Het.: Pentatomidae)

2016

The Brown Marmorated Stink Bug Halyomorpha halys (Heteroptera: Pentatomidae), is a very polyphagous pest of fruit crops, horticultural crops and ornamentals. Native from eastern Asia, this invasive species was recorded for the first time in Modena in 2012 and is now spreading in Northern and Central Italy. With its establishment in the invaded areas, new interactions with native tri-trophic systems (plants - stink bugs - parasitoids) are expected. A plant attacked by an ovipositing stink bug may respond by the emission of induced plant synomones, which are exploited by egg parasitoids for host location (indirect defences). This mechanism had been studied for coevolved tritrophic systems at …

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…

Contenimento naturale di Bactrocera oleae (Rossi): clima o parassitoidi? Confronto tra Western Cape (Sud Africa) e Sicilia

2017

Bactrocera oleae (Rossi), mosca delle olive, è presente anche in Sud Africa, ma finora non si sono avute notizie di infestazioni economicamente rilevanti negli oliveti. L’accertata presenza di un maggior numero di braconidi parassitoidi della mosca delle olive rispetto alle aree mediterranee è stata ed è considerata da molti autori la principale causa di queste minori infestazioni, senza che però siano stati eseguiti in Sud Africa adeguati studi sulle infestazioni da B. oleae e sui fattori cli- matici delle aree interessate. Analizzando recenti dati sui livelli d’infestazione di B. oleae registrati su olivo coltivato e selvatico nel Western Cape e in Sicilia, appaiono simili in una norm…