Osservazioni sull’acarocenosi dell’agrumeto e tecniche di controllo di Acari fitofagi, di Phyllocnistis citrella e di Aspidiotus nerii.

Virgins in the wild: mating status affects the behavior of a parasitoid foraging in the field

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…

Indagini sulla presenza del feromone sessuale in Phyllonorycter delitella (Duponchel)

Phyllonorycter delitella (Duponchel) (Lepidoptera: Gracillariidae) è un fillominatore che è stato rinvenuto nel 2004 nelle aree boschive siciliane su Roverella (Quercus pubescens Willd.). Nel presente lavoro si riportano i risultati delle indagini condotte sul feromone sessuale di questo fitofago, sotto il profilo comportamentale, chimico e morfologico. Per analizzare le risposte comportamentali di maschi vergini di P. delitella verso gruppi di femmine conspecifiche in fase di richiamo sono stati condotti biosaggi in olfattometro a due vie. Le prove hanno evidenziato un’attrazione significativa degli individui osservati verso le femmine vergini. Partendo da questi risultati è stata effettua…

Olfactory response of two aphid parasitoids, Lysiphlebus testaceipes and Aphidius colemani, to aphid-infested plants from a distance

The role of volatile stimuli in the host-searching behaviour of the two parasitoid species Lysiphlebus testaceipes Cresson and Aphidius colemani Viereck (Hymenoptera: Braconidae) was studied in relation to the host Aphis gossypii Glover (Homoptera: Aphididae) on cucumber plants, Cucumis sativa L. (Cucurbitaceae). Experiments were carried out in the laboratory in a wind tunnel, exposing individual parasitoids to signals from three sources simultaneously: (1) a complex of cucumber plants, Cucumis sativa , and A. gossypii ; (2) uninfested cucumber plants; and (3) dummy cardboard plants. The flight response of the female parasitoids was considered oriented when they landed on plants and non-ori…

Investigationes on population dynamics and mortality of Phyllocnistis citrella in western Sicily (Italy)

Population dynamics and mortality of P. citrella, and its natural enemies with parasitism levels in two different citrus orchards, sprayed and unsprayed, were investigated. The effect of host density on percentage parasitism and mortality was calculated by regression analyses. In both sites, over the 3-years period from 2002 to 2004, P. citrella was detected during the summer months and it was not found during the first flush. Population levels were low, never exceeding 3.0/leaf. P. citrella began to increase from June in 2002-2003 and from July in 2004. The monthly percentage parasitism of P. citrella in sprayed orchard fluctuated from 0 to 19%, while in unsprayed from 0 to 30%. High morta…

Indagini sulle infestazioni di Aphis gossypii Glover su melone invernale (Cucumis melo Var. Helios) in aziende a conduzione biologica della Sicilia occidentale.

Investigations on the aphid infestation occurring on winter melon crops (Cucumis melo var. Helios) in organic farms of western Sicily The winter melon (Cucumis melo L.) is an important crop in Sicily. Previous studies carried out in western Sicily have shown that the aphid species Aphis gossipii is the key pest of winter melon crops.A. gossypii is a cosmopolitan species with very polyphagous habits; this phytophagous insect is capable of serious economic damage due to direct feeding of the sap plant and due to the honeydew secretion and the consequent presence of sooty mold and due to the possible transmission of viruses. The aim of this work was to investigate the levels of aphid infestati…

Oviposition deterrence and repellent activities of selected essential oils against Tuta absoluta Meyrick (Lepidoptera: Gelechiidae): laboratory and greenhouse investigations

AbstractTuta absoluta, an invasive pinworm characterized by high reproductive potential and adaptation to different agroecological conditions, cause serious damage to tomato crops. Chemical control with synthetic insecticides is widely used to control this pest, although pesticides exhibit side effects on non-target organisms and negatively impact the environment, with the occurrence of resistance to some active substances in the target pest. The use of essential oils (EOs) from aromatic or officinal plants could represent an environmentally safe control method, alternative to synthetic insecticide application. In this work we investigated the effect of EOs from Spanish oregano, laurel, bas…

Studio sul feromone sessuale di Lysiphlebus testaceipes Cresson

Valutazione del metodo “attract and kill” con eco-trap nel controllo della mosca delle olive Bactrocera oleae Gmelin.

Il lavoro è stato svolto in quattro aziende a conduzione biologica della Sicilia occidentale avvalendosi delle risorse finanziarie istituite dal MiPAF, con il “Fondo per lo sviluppo dell’agricoltura biologica e di qualità” ed in ambito regionale dall’attuazione da parte del Servizio IV dell’Assessorato Regionale Agricoltura e Foreste del “Progetto di Sviluppo dell’Agricoltura biologica in Sicilia” sottoprogetto “Gestione fitosanitaria dell’agrosistema olivo”. Vengono riportati i dati inerenti l’efficacia del metodo “attract and kill” nei confronti delle infestazioni della mosca delle olive. In ciascuna delle quattro aziende, tre situate in zone collinari (indicate con A, B e C) e una a live…

Effetto del "mating status" sul foraggiamento di Lysiphlebus testaceipes Cresson

Indagini sulla presenza di Prays oleae in oliveti a conduzione biologica della Sicilia occidentale

Investigations on presence of Prays oleae in organic olive orchards of western Sicily. This paper reports a study on the population dynamics of the olive moth, Prays oleae (Bern) (Lep., Plutellidae) in four organic olive orchards in western Sicily (Italy), from 2007 to 2010. The influence of the phytophagous on the fruit drop was detected. Also, the efficacy of treatments with Bacillus thuringiensis var. kurstaki on damage reduction was evaluated. Flight trend was monitored using delta-wing traps (3/ha) containing the sexual pheromone ((Z)-7-tetradecenal), placed in each olive orchard. Traps were hung in the inner zone of the canopy to a height of 1.50 m, and checked weekly from May to 2-3 …

Ruolo dei parassitoidi oofagi nel controllo naturale dei fitofagi del nocciolo responsabili del “cimiciato delle nocciole” nel Parco dei Nebrodi (ME).

Role of oophagous parasitoids in the natural control of hazelnut bugs inducing the “cimiciato seeds” in Nebrodi Park (ME) Oophagous parasitoids of bugs collected on hazelnut cultivations and seasonal parasitism on eggs of Gonocerus acutengulatus (Goeze) were studied from 2004 to 2006 in the Nebrodi Park (ME). Samples of bug eggs were collected in three altitude areas, 300-590, 600-890 and 900-1100 m above sea level, and examined in laboratory. Parasitoid adults obtained from all eggs were identified. Parasitization levels, detected on G. acuteangulatus in all areas showed a similar trend with the most value on August. Significant regression between the total number of eggs and the number of…

I batteri associati al nettare fiorale influiscono sulle longevità degli insetti parassitoidi

I parassitoidi adulti frequentemente visitano le piante in fioritura, ricercando nettare fiorale per coprire i loro bisogni energetici e nutrizionali. In letteratura, infatti, i benefici del nettare sulla fitness dei parassitoidi sono ampiamente documentati. Sebbene il nettare fiorale costituisca un substrato ideale per la crescita di comunità microbiche che possono alterarne le caratteristiche organolettiche, l'effetto della fermentazione batterica del nettare sui parassitoidi non è stato ancora sufficientemente esplorato. In questo lavoro è stata studiata la longevità dei parassitoidi adulti utilizzando nettare sintetico fermentato da diversi ceppi batterici appartenenti ai phyla Firmicut…

Population dynamic of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) and parasitism levels in western Sicily (Italy).

Dinamica di popolazione di Aphis gossypii possibile vettore del Virus della Tristeza in un agrumeto della Sicilia occidentale

Tra le specie di afidi che attaccano gli agrumi in Sicilia, Aphis spiraecola Patch, Toxoptera aurantii (B.d.F) e Aphis gossypii Glover rivestono importanza economica, essendo presenti dalla primavera all’autunno con livelli di infestazione molto alti. Oltre ai danni legati all’attività trofica, tutte e tre le specie primarie, sono in grado di trasmettere il virus della Tristeza (CTV); in bibliografia l’efficienza è considerata alta nel caso di A. gossypii e poco rilevante nel caso delle altre due specie. La trasmissibilità del CTV, oltre che dalla specie vettrice, dipende da diversi fattori quali, le specie di Citrus donatrici o recettrici, la virulenza dell'isolato del virus, il comportame…

Evolution of Phyllocnistis citrella Stainton (Lepidoptera, Gracillaridae) and its parasitoids in the last five years in citrus orchards of the western Sicily (Italy)

Indagine su Henosepilachna elaterii (Rossi) (=Epilachna chrysomelina (F.)) e Raphidopalpa foveicollis (Lucas) in meloneti biologici della Sicilia occidentale.

Investigations on Henosepilachna elaterii (Rossi) and Raphidopalpa foveicollis (Lucas) in an organic cultivation of winter melon in western Sicily. A study on H. elaterii and R. Foveicollis, serious pests of winter melon, was conducted in two organic melon fields of the western Sicily. Dynamics of population and infestation levels were investigated. In addition, the possible influence of mulching on R. Foveicollis infestation has been taken into account. Our results showed that H. elaterii occurred only in one field from the beginning of June and it infested 60% of the plants in the mid-July, then the pest population density dropped to about 10%. R. foveicollis occurred in both locations fr…

Effects of essential oils of Origanum vulgare L. (Fam. Labiatee), Pelargonium odoratissimum L. (Fam. Geraniaceae) and Syzygium aromaticum L. (Fam. Mirtaceae) on mortality of Aphis gossypii Glover (Homoptera: Aphidiidae) in laboratory

The cotton aphid, Aphis gossypii Glover (Homoptera: Aphidiidae), is a cosmopolitan and highly polyphagous species causing serious economic damage to numerous plants including Cucurbitaceae. The use of synthetic insecticides represent the main method of control of this aphid, often resulting in resistance to all the major insecticide group. The use of natural products, such as essential oils (EOs), has increased in recent years because they have advantages in reduction of this resistance. Within this research area, we have implement and evaluate the applications of EOs that aim at reinforcing knowledge on the control of this aphid. We investigated the topical application of the EOs of Origan…

Female-released sex pheromones mediating courtship behavior in Lysiphlebus testaceipes males.

Ethological aspects and chemical communication at close-range between the sexes of Lysiphlebus testaceipes Cresson (Hymenoptera: Braconidae) have been investigated through behavioral bioassays and chemical analysis. The attractiveness toward males of whole-body extracts of females and males in hexane and acetone was evaluated, adopting male fanning behavior as a key behavioral component. Also, the activity of polar and nonpolar fraction of female-body extract in hexane obtained using solid-phase extraction technique was investigated. In order to identify cuticular compounds, male and female whole-body extracts with hexane and acetone were analyzed by gas chromatography-mass spectrometry. Th…

Responses of Aphytis chilensis to the synthetic sex pheromone of the Oleander scale

Evidence of Seasonal Variation in Body Color in Adults of the Parasitoid Cirrospilus pictus (Hymenoptera: Eulophidae) in Sicily, Italy

As part of the studies on the morphological color variation of insects, a case study on the seasonal body color variation of Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae: Eulophinae) parasitoid of leafminers is reported. Observations were made from January 2000 to December 2003 in north-western Sicily (Italy), in relation to sex, body regions of adults and seasonal periods. Wasps parasitizing Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) were collected from organic citrus orchards (Citrus limon L., var. “Femminello zagara bianca” and “Femminello comune”). Adults were grouped in classes: yellow males, black males, yellow females, yellow–black females and black females. …

Influenza delle infrastrutture ecologiche poste ai margini del vigneto su Empoasca vitis (Goethe) (Homoptera: Cicadellidae) e il suo parassitoide Anagrus atomus L. (Hymenoptera: Mymaridae)

È ormai opinione diffusa che la diversità vegetale all’interno degli agrosistemi favorisca il mantenimento dell’entomofauna utile ai fini di un contenimento naturale di fitofagi. In quest’ambito, il presente lavoro ha riguardato uno studio, sulle popolazioni di Empoasca vitis e del suo parassitoide Anagrus atomus in un’azienda viticola sita nel comprensorio di Salemi (TP) (446 m s.l.m.) a conduzione biologica prendendo in considerazione due appezzamenti, uno con ai margini siepi di rovo, rosa canina e rosmarino e l’altro in assenza di siepi. Nel periodo vegeto-produttivo della vite (marzo-ottobre 2012), si è valutata l’influenza della specie vegetale e della variazione della distanza delle …

The parasitoid complex of Prays oleae (Bern.) in organic olive orchard.

Ecological infrastructures in a vineyard of West Sicily

Adulticidal activity of essential oils of Mentha piperita L., Cupressus sempervirens L., and Eucalyptus globulus Labill. against the tomato leafminer Tuta absoluta Meyrick (Lepidoptera: Gelechiidae)

The tomato miner Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) is a Neotropical species, which cause serious damages to tomato both in open fields and under greenhouses. Chemical control using synthetic insecticides was the primary method of control of this pest, but it has showed negative implications due to high costs, and risks for human health and environment. Therefore safer alternatives are required to control of tomato leafminer as the use of natural insecticides. In this work we investigated the insecticidal activity of essential oils (EOs) of peppermint, Mentha piperita L., cypress, Cupressus sempervirens L., and eucalyptus, Eucalyptus globulus Labill., used for the first time a…

Investigations on Tuta absoluta (Lepidoptera: Gelechiidae): larval infestation on the tomato cultivated in open field and evaluation of five essential oils against larvae in laboratory

Abstract The tomato miner Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) is a Neotropical species, which cause serious damages to tomato in spread areas. It appeared in 2008 in Italy, where it seriously threatened tomato production both in greenhouse and open field cultivations. In this work a study on infestation by this leafminer on leaves was conducted in an organic cultivation of tomato (Lycopersicon esculentum Mill.) "Pizzutello" variety in Sicily (Italy), and the insecticidal activity of 5 essential oils (EOs) on T. absoluta was evaluated in laboratory. EOs of basil, cypress, laurel, peppermint and Spanish oregano were used against 3rd- and 4th-instar larvae to assess contact effect…

Le infrastrutture ecologiche come elemento funzionale nella gestione della biodiversità degli agrosistemi, con particolare riferimento al vigneto

Molti studiosi, già da diverso tempo, hanno messo in risalto l’importanza della diversità vegetale negli agroecosistemi sull’aumento della presenza di artropodi utili che contribuiscono al contenimento delle specie dannose. In quest’ambito una strategia di difesa per mantenere alto il livello di biodiversità riguarda l’uso delle cosiddette “infrastrutture ecologiche” o “aree di compensazione ecologica”, cioè siepi o fasce di vegetazione adiacenti al campo coltivato o al suo che forniscono ospiti alternativi e siti rifugio per predatori e parassitoidi di insetti dannosi, aumentando in tal modo l’abbondanza dei nemici naturali e la colonizzazione delle colture confinanti. Alcuni lavori di cam…

Mytilococcus gloverii (Packard) (Homoptera: Diaspididae) parasitism by Encarsia herndoni Girault (Hymenoptera: Aphelinidae) twenty years after its introduction into western Sicily

Studies on Reticulitermes lucifugus Rossi (Isoptera: Rhinotermitidae): a review of associated hindgut flagellates and investigations on protist species of the Sicilian subspecies, R. lucifugus “Sicily”

The present study was conducted on protist species from R. lucifugus “Sicily” subspecies in a field site of Palermo (Sicily, Italy) on June 2015. Since protist species associated with R. lucifugus in Europe are still confused and recent revisions are lacking, this work aims at achieving greater clarity on these symbiosis trough a review of the literature in light of new phylogenetic studies on this termite species. The purpose of this work was also to highlight and quantify protists associated with the Sicilian subspecies, R. l. “Sicily”. Results pointed out the real protist community attributable to R. lucifugus from the literature and showed 13 protist species detected in the subspecies R…

Dinamica di popolazione dei fitofagi causa del "cimiciato delle nocciole" nel Parco dei Nebrodi (ME) con particolare attenzione a Gonocerus acuteangulatus (Goeze)(Hemiptera: Coreidae)

Sex pheromone of Lysiphlebus testaceipes (Hymenoptera Braconidae)

Prove di lotta contro Aspidiotus nerii Bouchè (Homoptera: Diaspididae) in un limoneto biologico della Sicilia occidentale.

Analisi del comportamento delle femmine vergini e accoppiate di Lysiphlebus testaceipes Cresson (Hymenoptera; Braconidae) in relazione alla dimensione delle colonie afidiche

Strategie di controllo di Bactrocera oleae (Rossi) con metodi alternativi agli interventi convenzionali in oliveti biologici della Sicilia occidentale

This work reports studies on the population dynamics and safe control strategies of Bactrocera oleae in four unsprayed olive groves of western Sicily from 2007 to 2010. The main management tools for B. oleae evaluated were the“Attract and Kill” lures (Ecotrap Vioryl), the use of sardines (traditional practice) and Nu-lure (innovative) and the spinosad (innovative) which is a selective insect control product produced by the fermentation of a naturally occurring soil bacterium, Saccharopolyspora spinosa. Flies trend were carried out by pheromone traps and the level of infestation counting the number of fruits with pest eggs, larvae and pupae and hole hatching. Results showed that in all olive…

Effetti di oli essenziali estratti da piante mediterranee su Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae)

Studio sui livelli di infestazione e sulla dinamica di popolazione di Bactrocera oleae Gmelin (Diptera: Tephritidae) in oliveti biologici siciliani

Il presente lavoro riporta uno studio pluriennale, dal 2000 al 2003, sulla evoluzione dell’infestazione e la dinamica della popolazione della mosca delle olive, Bactrocera (=Dacus) oleae (Diptera: Tephritidae), in agrosistema oliveto non soggetto a trattamenti chimici, allo scopo di individuare il momento di intervento e il metodo più idoneo da utilizzare per la lotta contro il fitofago. In particolare la ricerca è stata condotta in due oliveti a conduzione biologica siti in diverse località della Sicilia occidentale e ha riguardato l’andamento dell’infestazione totale (percentuale di olive con segni di attacco) e attiva (percentuali di olive contenenti uova, larve o pupe vive), le curve di…

The role of cuticular hydrocarbons of Lysiphlebus testaceipes Cresson (Hymenoptera, Braconidae) in the sex recognition behaviour

Indagine su Raphidopalpa foveicollis (Lucas) nella coltura del melone biologico della Sicilia occidentale.

Investigations on Raphidopalpa foveicollis (Lucas) in an organic cultivation of winter melon in western Sicily Red pumpkin beetle (Raphidopalpa foveicollis), is a Chrysomelidae beetle that lives on various species of cucurbits with greater preference for Cucumis sp. Both larval and adult stages are injurious to the crops. The former feeds on roots and stems of the plants, while the latter feeds on foliage, petals and fruits. In Sicily, this insect has occurred in the past as a secondary pest on the winter melon, but sometimes it reaches levels of infestation to arouse considerable concern among farmers. In order to implement economic methods of pest control a study on organic cultivation of…

Evolution of Phyllocnistis citrella Stainton (Lepidoptera, Gracillariidae) and its parasitoids in the last five years in citrus orchards of western Sicily (Italy)

Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is native to India, China, and other Southeast Asian countries that has spread rapidly since 1993 to all citrus-growing areas of the world. In Italy, the pest was first discovered during the autumn of 1994, in some citrus groves of Sardinia and, subsequently, in Sicily in the summer of 1995 showing a very rapid range expansion in other citrus-growing regions of Italy. Currently, damage to mature trees under typical Mediterranean conditions is considered only aesthetical, but P. citrella causes economic problems on young trees, nurseries, and overgraftings. Since the first occurrence of the citrus leafminer in Sicily, several ind…

Studio sul complesso parassitario di Prays oleae (Bernard) e sui livelli di parassitizzazione in un oliveto biologico della Sicilia occidentale.

Study on the parasitoid complex of Prays oleae (Bernard) and parasitism levels in an organic olive orchard in western Sicily (Italy). Prays oleae is a serious pest of the olive tree in the Mediterranean basin. This phytophagous infests fruits (carpophagous generation) and leaves (phyllophagous generation). In cases of high population densities crop losses, caused mainly by fruit drop, may be heavy. The aim of this work was to investigate on 1) parasitoid species living on P. oleae, 2) their incidence parasitoid complex, 3) parasitism levels and 4)the influence on the fruit fall. Observations were conducted in an organic olive grove near Contessa Entellina (PA) (Sicily, Italy) (37.43.44 N; 1…

Indagine sulle specie afidiche e loro nemici naturali in un’area del Parco d’Orleans di Palermo