Search results for "SCELIONIDAE"
showing 10 items of 27 documents
Effect of host kairomones and oviposition experience on the arrestment behavior of an egg parasitoid
2006
SUMMARY Chemical residues left by walking adults of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae) induce arrestment behavior in the egg parasitoid Trissolcus basalis (Wollaston)(Hymenoptera: Scelionidae) leading to prolonged periods of walking on contaminated areas and to systematic return to the stimulus after encountering the treatment borders. In this study, we quantified how the hierarchical value of residues from host adults and oviposition experience can influence the arrestment behavior of T. basalis females. Our results showed that:(1) female wasps perceived host residues at different hierarchical levels depending on the host gender, with a clear pre…
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…
Host specificity in the egg parasitoid Telenomus busseolae is mediated by sex pheromone compounds
2007
Several studies showed that egg parasitoids are able to detect host sex pheromones produced by adult hosts as a host cue. In this way female wasps are directed toward an area where host mating is in progress and where an oviposition has probably taken place or is soon to occur. Telenomus busseolae Gahan (Hymenoptera: Scelionidae) is a solitary egg parasitoid of various noctuids (Lepidoptera, Noctuidae) belonging to the genera Sesamia. In field observations, it has been demonstrated that T. busseolae reacts to the pheromone emitted by females of the corn stalk borer, Sesamia nonagrioides (Lefebvre) and the pink stem borer, Sesamia calamistis (Hampson). It is known that the sex pheromone prod…
World revision of the genus Encyrtoscelio Dodd (Hymenoptera: Scelionidae)
1995
The genus Encyrtoscelio Dodd is revised. E. apterus (Szelényi), E. mirissimus Dodd, E. turneri Waterston are redescribed, and six new species are described: E. cydni Caleca, E. japonicus Caleca, E. mediterraneus Caleca, E. miroides Caleca, E. spuratus Caleca and E. undecim Caleca. A key to separate females is presented, and is based on the number of antennomeres and claval sensillar formula, mandibular spurs and teeth, palpal formula and clypeus, and some cephalic characters. Morphological adaptations of the head and mandibles are discussed in relation to host habitat and oviposition site. Information on host associations, habitat preference, seasonal and daily occurrence of some species a…
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 …
Intraguild interactions between two egg parasitoids exploring host patches
2010
Intraguild interactions between two egg parasitoids, Trissolcus basalis (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Hymenoptera: Encyrtidae), exploring egg masses of the Southern Green Stink Bug (SGSB) Nezara viridula (Heteroptera: Pentatomidae), were investigated in laboratory conditions by single, simultaneous and sequential host attack experiments. Mortality of N. viridula eggs was higher in simultaneous and sequential releases compared to single species releases. In simultaneous host exploitations, T. basalis females displayed an aggressive behavior against O. telenomicida females. The outcome of multiparasitism showed that interspecific larval competition was dominated by O…
The ovipositing female of Ooencyrtus telenomicida relies on physiological mechanisms to mediate intrinsic competition with Trissolcus basalis
2012
Ongoing studies by our group showed that the outcome of the intrinsic competition between two solitary egg parasitoids, Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae), is dominated by O. telenomicida. In this article we investigated the role played by the ovipositing O. telenomicida female in the suppression of a T. basalis competitor. Laboratory experiments were conducted by allowing an O. telenomicida female to puncture the eggs of Nezara viridula (L.) (Heteroptera: Pentatomidae) with her ovipositor (= no oviposition) or to parasitize them. The results show that O. telenomicida relies on some physiological mechan…
Kairomonal effect of walking traces from Euschistus heros (Heteroptera: Pentatomidae) on two strains of Telenomus podisi (Hymenoptera: Scelionidae)
2003
. The semiochemical cues used by geographically isolated strains of the parasitoid, Telenomus podisi (Ashmed), to find eggs of the stink bug Euschistus heros were investigated. Two strains of Te. podisi, maintained on eggs of a South American host (E. heros) were studied. One parasitoid strain originated from specimens collected near Brasilia, Brazil (SA strain), and a second strain originated from specimens collected at Beltsville, Maryland (NA strain). Cold tolerance tests of adults from the NA and SA Te. podisi strains, analyses of the cuticular hydrocarbons between the two strains, and crossing experiments between strains each indicated consistent differences between the NA and SA stra…
Source of the host marking pheromone in the egg parasitoid Trissolcus basalis (Hymenoptera: Scelionidae).
2001
After oviposition, Trissolcus basalis females always mark the host's surface, depositing host marking substances for herself and to warn other ovipositing females. The perception of these host marking substances, probably through the antennae, can induce the female to leave and seek healthy hosts. Parasitoid females exposed to conspecific parasitized egg masses left the host egg masses significantly more often than when exposed to non-parasitized egg masses. More egg mass leaving behavior also was observed when the egg masses were treated with Dufour's gland secretion but not when treated with secretion from the common oviducts. The common oviduct has a secretory epithelium that produces el…