Search results for " Entomologia"
showing 10 items of 590 documents
Virgins in the wild: mating status affects the behavior of a parasitoid foraging in the field
2008
In haplodiploid organisms, virgin females can produce offspring, albeit only sons. They may therefore face a trade-off between either: (1) searching for hosts and producing sons immediately; or (2) searching for mates and perhaps producing both sons and daughters later in life. Although this trade-off raises a theoretical interest, it has not been approached experimentally. The objective of this article is thus to document the effect of mating status on the foraging behavior of a haplodiploid parasitoid. For this, we recorded the behavior of virgin and mated female Lysiphlebus testaceipes (Hymenoptera: Braconidae) after being released, in the field, on a colony of their aphid hosts. Half of…
A new voice from Sardinia: Uromenus annae (Targioni-Tozzetti, 1881 (Insecta: Orthoptera: Tettigoniidae: Bradyporinae: Ephippigerini)
2019
Recent findings of the Sardinian endemic Bushcricket Uromenus annae (Targioni Tozzetti, 1881) allowed the authors to retrace the nomenclatorial history of the species. The rearing of living specimens resulted in the recording of the male song, previously unknown. Since the Neotype previously established by Fontana & Buzzetti (2001) is lost, a new Neotype is here designated. Affinities with other congeneric species are discussed.
Evaluating resistance to Bt Toxin Cry1Ab by F-2 Screen in European populations of Ostrinia nubilalis (Lepidoptera: Crambidae)
2010
The large-scale cultivation of transgenic crops producing Bacillus thuringiensis (Bt) toxins have already lead to the evolution of Bt resistance in some pest populations targeted by these crops. We used the F2 screening method for further estimating the frequency of resistance alleles of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), to Bt maize, Zea mays L., producing the Cry1Ab toxin. In France, Germany, and Italy, 784, 455, and 80 lines of European corn borer were screened for resistance to Mon810 maize, respectively. In Slovakia, 26 lines were screened for resistance to the Cry1Ab toxin. The cost of F2 screen performed in the four countries varied from U.…
Investigation of long-range female sex pheromone of the European tarnished plant bug, Lygus rugulipennis: chemical, electrophysiological, and field s…
2004
The European tarnished plant bug, Lygus rugulipennis, is an important pest of agricultural and horticultural crops throughout Europe. Adult male L. rugulipennis were previously shown to be attracted to traps baited with live virgin females, which suggests the females produce a sex pheromone. Volatiles produced by virgin female L. rugulipennis were shown to contain three components, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal which elicited electroantennographic (EAG) responses from males in analyses by linked gas chromatography–electroantennography (GC-EAG). They were produced in 1.5:1:0.08 ratio, respectively, by single females. Collections from 1, 2, or 4 virgin female…
Revision of the genus Prionotropis Fieber, 1853 (Orthoptera: Pamphagidae: Thrinchinae)
2015
The genus Prionotropis Fieber, 1853 is revised. It is distributed in scattered areas of the Mediterranean region from Turkey in the East to Spain in the West. Overall, seven species are listed, namely P. maculinervis (Stål, 1878) (Turkey; P. urfensis Ramme, 1933 is here considered its synonym), P. willemsorum n. sp. (Greece, Epirus; previously considered P. appula), P. appula (O.G. Costa, 1836) (South Italy), P. hystrix (Germar, 1817) (Bosnia and Herzegovina, Slovenia, Croatia, North-East Italy; P. hystrix sontiaca is here synonymized), P. rhodanica Uvarov, 1923 resurrected status (France, Crau, Rhone delta; here considered a valid species), P. azami Uvarov, 1923 n. status (France, Var regi…
Biological and life table parameters of Typhlodromus laurentii and Iphiseius degenerans (Acari, Phytoseiidae) fed on Panonychus citri and pollen of O…
2015
Typhlodromus laurentii and Iphiseius degenerans are two generalist phytoseiid mites, broadly spread in the Mediterranean area, especially in citrus orchards. In the present work we report results on various biological and life table parameters of the two phytoseiids, fed on pollen of Oxalis pes-caprae and various stages of the tetranychid Panonychus citri. Iphiseius degenerans had the shortest post embryonic development (6.53 days), the highest oviposition rate (1.83 eggs/female/day) and the shortest mean time between eggs laid (0.55 day) on Oxalis pollen, whereas the two food types did not influence these parameters in T. laurentii. However, Oxalis pollen showed a positive effect on the su…
Host sex discrimination by an egg parasitoid on Brassica leaves.
2011
Egg parasitoids are able to find their hosts by exploiting their chemical footprints as host location cues. In nature, the apolar epicuticular wax layer of plants that consists of several classes of hydrocarbons serves as the substrate that retains these contact kairomones. However, experiments on chemical footprints generally have used filter paper as substrate to study insect behavior. Here, we explored the ability of Trissolcus basalis (Scelionidae) females to discriminate between footprint cues left by male and female Nezara viridula (Pentatomidae) on leaves of their host plant Brassica oleracea (broccoli). Furthermore, we analyzed the chemical composition of the outermost wax layer of …
The Egg Parasitoid Trissolcus basalis uses n-nonadecane, a Cuticular Hydrocarbon from its Stink Bug Host Nezara viridula, to Discriminate Between Fem…
2007
Contact kairomones from adult southern green stink bugs, Nezara viridula (L.) (Heteroptera: Pentatomidae) that elicit foraging behavior of the egg parasitoid Trissolcus basalis (Wollaston) were investigated in laboratory experiments. Chemical residues from tarsi and scutella of N. viridula induced foraging by gravid female T. basalis. Residues from body parts of female N. viridula elicited stronger responses than those from the corresponding body parts of males. Deproteinized tarsi still elicited searching responses from wasps, indicating that the kairomone was not proteinaceous. Hexane extracts of host cuticular lipids induced searching responses from T. basalis, with a strong preference f…
Il contributo del letame alla nematofauna
2023
Gli effetti benefici del letame sul suolo e sulla resa delle colture sono stati ampiamente dimostrati grazie al suo alto contenuto di sostanza organica. Inoltre, il letame può aumentare l'attività biologica e la diversità degli organismi del suolo, il che a sua volta può portare a ridurre al minimo i danni alle colture da agenti patogeni presenti nel suolo. Inoltre numerose sono le segnalazioni sul successo dell'applicazione del letame al fine di ridurre i nematodi delle lesioni radicali in diversi sistemi colturali. Tuttavia, al meglio delle nostre conoscenze ci sono pochi studi sulla caratterizzazione delle comunità di nematodi su letame maturo. E' stato quindi intrapreso uno studio per v…
Does the immune answer to Bacillus thuringiensis infection is the same in larvae, females and males of Rhynchophorus ferrugineus?
2021
Bacillus thuringiensis (Bt) è considerato un potenziale batterio entomopatogeno per la lotta al Rhynchophorus ferrugineus, coleottero da quarantena infestante le palme. In questo lavoro si considerano gli effetti dell’infezione di Bt in larve, maschi e femmine del punteruolo rosso. La patogenicità è stata valutata stimando la LD50 (Lethal Median Dose) e la LT50 (Lethal Median Time), il numero totale di emociti ed il tipo di emociti (Differential Haemocytes counts) ed inoltre l’espressione delle proteine Heat Shock Protein 70 (HSP70) negli emociti e nel cerebro. La mortalità di entrambi i sessi e delle larve aumentava all’aumentare della dose e del tempo di esposizione. Tuttavia le larve han…