Search results for "parasitoids"

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…

Sexual communication in the egg parasitoid Trissolcus brochymenae

2009

The males of the egg parasitoid Trissolcus brochymenae (Hymenoptera Scelionidae) exploit a short range pheromone for recognition of the other gender. To evaluate the role of this pheromone, the behavior of virgin males has been studied in closed arena when exposed to the following cues: 1) virgin females (alive, dead "washed" with solvents, dead" unwashed"); 2) dissected and re-assembled virgin females (females dissected into head, mesosoma, and gaster, then reassembled using two solvent "washed" parts and an "unwashed” part, or "unwashed" legs assembled with entire" washed" body); 3) "washed" females treated with acetone extracts (of virgin females and of legs). Males antennate and mount v…

Evaluating the quality of the Mexican fruit-fly, Anastrepha ludens, as host for the parasitoid Melittobia digitata

2013

We investigated the presence of Melittobia digitata (Hymenoptera: Eulophidae) and its associations with its natural hosts in Veracruz, Mexico. The parasitoid was confirmed to be present and found to attack prepupae of Trypoxylon and Sceliphron (Hymenoptera: Crabronidae and Sphecidae, respectively) mud daubers as well as pupae of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae). Since A. ludens is a very important pest of citrus and mango in Mexico and Central America, we evaluated, in laboratory experiments, the quality of A. ludens as host of M. digitata comparing the development of the parasitoid in another unrelated fly species (Sarcophaga [Neobellieria] bullata) (Diptera: …

The response of Trissolcus basalis to footprint contact kairomones from Nezara viridula females is mediated by leaf epicuticular waxes.

2009

Chemical footprints left behind by true bugs are perceived as contact kairomones by scelionid egg parasitoids. Female wasps encountering a contaminated artificial substrate display a characteristic arrestment posture, holding the body motionless and antennating the surface. In the system Nezara viridula (L.) and its egg parasitoid Trissolcus basalis (Wollaston), previous studies have shown that the kairomone mediating such behavior is part of N. viridula's cuticular hydrocarbons (CHC) and furthermore that the wasp's ability to discriminate host male and female footprints is mainly based on the presence/absence of nonadecane (nC(19)). In this study, the effect of epicuticular waxes of leaves…