Search results for "Kairomone"
showing 10 items of 30 documents
Behavioral and Chemical Investigations of Contact Kairomones Released by the Mud Dauber Wasp Trypoxylon politum, a Host of the Parasitoid Melittobia …
2011
Contact kairomones from the host mud dauber wasp Trypoxylon politum Say (Hymenoptera: Crabronidae) that mediate behavioral responses of its ectoparasitoid Melittobia digitata Dahms (Hymenoptera: Eulophidae) were investigated. Chemical residues from host by-products, the cocoon, and the meconium, induced arrestment behavior of macropterous female parasitoids, while those from the host stage attacked, i.e., the prepupa, did not. Melittobia digitata response to polar and apolar extracts of host by-products indicated kairomone(s) solubility mainly in hexane. GC and GC/MS analysis of cocoon and meconium apolar extracts revealed a mixture of linear carboxylic acids from C(6) to C(18), and both ex…
Chemical ecology of Bagrada hilaris (Burmeister) (Heteroptera: Pentatomidae): intraspecific and interspecific chemical cues
2020
The chemical ecology of Heteroptera insects is determined by a wide array of chemical signals (semiochemicals) that drive their behavior at intra- and inter-specific level. Intraspecific semiochemicals are called pheromones, interspecific chemicals are named allelochemicals. In the case of stink bugs, sex-pheromones and aggregation pheromone are produced by adult males. Furthermore, phytophagous stink bugs exploit chemical cues emitted from plants to find a suitable food and oviposition source. The semiochemicals involved in this process are named kairomones and are generally formed by specific blend or key odorants emitted from host plant. The chemical ecology of the phytophagous Pentatomi…
The behavioral responses of the egg parasitoid Ooencyrtus telenomicida to semiochemicals from first and second trophic level
2009
In this study the responses of females of the egg parasitoid Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae) to volatile and contact chemicals from its host Nezara viridula (L.) (Heteroptera: Pentatomidae) and from host plant Solanum lycopersicum L. were investigated in a Y-tube olfactometer and in open arena. Our results in the Y-tube olfactometer tests showed that: (1) female wasps were attracted to volatiles from adult host virgin male and to volatiles from a host mated female, showing a clear preference for the volatiles emitted from the former; volatiles from host virgin females did not attract O. telenomicida females; (2) only volatiles produced by host-damaged plant com…
Plant surface mediates interaction between true bug chemical footprints and scelionid egg parasitoids
2009
Chemical footprints left behind by true bugs act as contact kairomones inducing an arrestment response in scelionid egg parasitoids. Once in contact with contaminated substrates, female wasps display a characteristic arrestment posture followed by an increase of the host searching time. Previous studies were conducted on artificial substrates as filter papers, so that little is known about the effects of natural substrates on behavioural response by wasps. In field, the substrate where these interactions occur, i.e. the surface of plants, is covered by wax layers that can have a role in trophic interactions between insects. In this study, we investigated the influence of plant surfaces on a…
Behavioral responses of the parasitoid Melittobia digitata to volatiles emitted by its natural and laboratory hosts
2010
Responses of macropterous females of the ectoparasitoid Melittobia digitata Dahms (Hymenoptera: Eulophidae) to direct and indirect cues emitted by its natural hosts as well as laboratory hosts were investigated using a Y-tube olfactometer. To locate the nest ofmud dauber wasps, Trypoxylon politum Say (Hymenoptera: Crabronidae), and one of their inquilines, Anthrax spec., parasitoids exploit volatiles from the freshly built nest mud and the empty cocoon constructed by the wasps, as well as their meconium. However, the parasitoids did not respond to odors emitted by older nest mud or by the host stages that are attacked (T. politum prepupae and Anthrax spec. larvae). Melittobia digitata was n…
Endogenous and exogenous factors affecting host chemical footprint exploitation by a hymenopterous egg parasitoid
2014
During the host location process, parasitoids encounter and explore a great variety of volatile and contact semiochemicals from the host-plant complex. In the system Nezara viridula and its egg parasitoid Trissolcus basalis, when wasps land on a plant, they can taste chemical footprints left by walking adult hosts. These cues represent a set of indirect host-related contact kairomones that induce arrestment and motivated searching behavior, as they drive wasps in an area where there is a high probability of finding hosts but are not able to “promise” the presence of the suitable host stage. Patch time allocation is strongly modified by experience gained during foraging on host traces. In fa…
Essential oils composition of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae – Periplocoideae)
2012
The essential oil of roots, branches, leaves, flowers and fruits of Periploca laevigata Aiton subsp. angustifolia (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analysed. The analyses allowed the identification and quantification of 86 volatile compounds. Branches showed the higher diversity with 57 compounds followed by fruits with 33, roots with 23, flowers with 16 and leaves with six compounds, respectively. In the matrices examined three constituents, heneicosane, docosane and tricosane are in common, although with different percentages. At least the most abundant compounds found in the matrices have been reported to have several biologica…
Essential oils composition of two Sicilian cultivars of Opuntia ficus-indica (L.) Mill. (Cactaceae) fruits (prickly pear).
2013
The essential oils composition of the skin, pulp and seeds from fruits of two Sicilian cultivars of Opuntia ficus-indica (cv. Sanguigna and cv. Surfarina) has been obtained by hydrodistillation and the possible antioxidant, antimicrobial and semiochemical roles have been investigated comparing the data with those reported in the literature. The presence of antioxidants and antimicrobials found in this study increases the spectrum of compounds that have beneficial properties in O. ficus-indica. In addition, several compounds identified in this study have been reported to influence the behaviour of Ceratitis capitata, a phytophagous pest which causes severe damages to several crops including …
Spider cues stimulate feeding, weight gain and survival of crickets
2014
1. To avoid predation, prey often change their behaviour upon encountering cues of predator presence. Such behavioural changes should enhance individual survival, but are likely to be energy-demanding. This should deplete energy reserves of the prey, unless it increases food intake. 2. These hypotheses were studied by conducting two microcosm experiments. In the first, crickets were kept on plants previously occupied by a spider or on control plants. After 3 days leaf consumption and weight gain of the crickets were quantified. In the second experiment, crickets were kept in the presence or absence of spider cues for 3 days. Spiders were then added and predation of the crickets was recorded…
Sub-lethal effects of deltamethrin on walking behaviour and response to host kairomone of the egg parasitoid Trissolcus basalis.
2002
The lethal doses of the pyrethroid deltamethrin were estimated for the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae), and the sub-lethal effects of an LD25 on female walking behaviour were evaluated. Linear speed of treated parasitoids was reduced compared with that of untreated ones for a period of up to 24 h. The sub-lethal effects of deltamethrin on parasitoid response to patches contaminated by a contact kairomone from its host, Nezara viridula L (Heteroptera: Pentatomidae), was also evaluated. Both treated and untreated parasitoids responded to host-contaminated patches by increasing residence time and decreasing linear speed. However, treated females showed …