Search results for "BIOLOGICAL CONTROL"

Nectar-Inhabiting Bacteria Affect Olfactory Responses of an Insect Parasitoid by Altering Nectar Odors

2022

AbstractFloral nectar is ubiquitously colonized by a variety of microorganisms among which yeasts and bacteria are the most common. Microorganisms inhabiting floral nectar can alter several nectar traits, including nectar odor by producing microbial volatile organic compounds (mVOCs). Evidence showing that mVOCs can affect the foraging behavior of insect pollinators is increasing in the literature, whereas the role of mVOCs in altering the foraging behavior of third-trophic level organisms such as insect parasitoids is largely overlooked. Parasitoids are frequent visitors of flowers and are well known to feed on nectar. In this study, we isolated bacteria inhabiting floral nectar of buckwhe…

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…

Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus ferrugineus

2012

BACKGROUND:The control ofRhynchophorusferrugineus (Olivier), themainpalmpest in theMediterraneanBasin, is problematic because of its biology and the current restrictions inmany European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS: The overall percentage of infected insects found in Canary palms was 7%. In laboratory bioa…

The role of chemical cues in the host finding behaviour of Trissolcus basalis from a Conservation Biological Control perspective

In assessing successful biological control programs by parasitoids, the knowledge of important traits, such as the host finding capability, i.e. the ability to find host and food resources, play the key role. Moreover, parasitoids in their natural environment parasitoids deal with a variable mixtures of natural cues. Some chemical cues are used by the wasps to locate their hosts, some ones drive wasps to feeding resources. The parasitoid response to these cues can fluctuate according to biotic factors and abiotic condition. This dissertation focus in details on the role of two important tools, such as selective flowering plants as food resources to add within a crop area and the traces left…

Egg parasitoids of stink bugs: Research status and potential for biological control

2012

Egg parasitoids are among the most important natural enemies associated with herbivorous stink bugs, and they show remarkable potential as biological control agents. On the other side, some egg parasitoid species also attack predaceous bugs, thus affecting the efficacy of these important entomophagous insects. Most studied stink bug egg parasitoids belong to Platygastridae (=Scelionidae) and Encyrtidae, the main research topics concerning behavior, chemical ecology, behavioural ecology and field efficacy. Some species have been used for biological control programs. However, some constraints may prevent egg parasitoids from becoming effective agents in inundative biocontrol projects, the mos…

FIRST RECORD IN TUNISIA OF CLOSTEROCERUS CHAMAELEON (GIRAULT) PARASITOID OF THE EUCALYPTUS GALLWASP OPHELIMUS MASKELLI (ASHMEAD) (Hymenoptera Eulophi…

2010

Closterocerus chamaeleon (Girault) (Hymenoptera Eulophidae), parasitoid of the Eucalyptus gall wasp Ophelimus maskelli (Ashmead) (Hymenoptera Eulophidae) has been recorded for the first time in Tunisia in July 2007. This record suggests that 14 months after its release in Sicily, in May 2006, it has spread over Sicily Channel.

Effect of Bacillus thuringiensis as vegetative form on hemocytes of Rhynchophorous ferrugineus (Coleoptera Curculionidae) larvae

2010

The bacterium Bacillus thuringiensis (Bt) is a pathogen of many insect species and is actively used in biocontrol. The vegetative form as been reported to be involved in insect septicemia process. Bt during the vegetative stage of growth, is known to secern a new family of insecticidal proteins. Moreover recently evidence has been provided, that B. thuringiensis can establish itself in replicative and vegetative form on the leaf surface. Little is known on the interaction of pathogens with the defense responses of phytophagous insects. Insect circulating hemocytes are primarily responsible for the immune defense against parasites and pathogens. We use as model Rhynchophorous ferrugineus Oli…

Fungi related to larvae of red palm weevil Rhynchophorous ferrugineus (Coleoptera: Curculionidae)

2010

As a first step to developing effective biocontrol strategies, we analyzed the pathogens and mainly the entomopathogenic fungal species, present into dead larvae of Rhynchophorous ferrugineus; a quarantine pest recently introduced and acclimated in Sicily (Italy). From 2008 to 2010, we estimated the natural larval mortality (> second instar) of R. ferrugineus collected from infested palm Phoenix canariensis; that was variable from 10 to 35%, according to the different seasons Among the different pathogens recorded the fungi seems have an important role, than in order to distinguish saprophytic or opportunistic species from potential pathogens (including the non cultivable ones) we applied d…

Pesticides: Chemical and Biological.

2013

There is a requirement by World Health Organization (WHO), Food and Agriculture Organization (FAO) and other International Organizations to develop environmentally sustainable systems for controlling pests that are less reliant on chemical pesticides as the primary management tool. However biological control alone cannot at the moment solve all pest problems and must be considered instrument to be used in combination with other methods. Compatibility of chemical pesticides (CP) and biological pesticides (BP) is one of the key for the implementation of Integrated Pest Management (IPM) programs. Testing the compatibility of CP and BP is necessary if these two agents are to be applied together…

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…