Search results for "Pheromones"
showing 10 items of 106 documents
Chemistry of pheromonal and defensive secretions in the nymphs and the adults ofDysdercus cingulatus Fabr. (Heteroptera, Pyrrhocoridae)
1991
59 ref.; International audience; The exocrine secretions from the nymphs and the adults of both sexes in D. cingulatus were chemically investigated. Seven compounds were identified in the anterior glands, and eleven in the median dorsoabdominal glands of nymphs and adults of both sexes. Fifty-five compounds were identified in the defensive glands (34 in posterior dorsoabdominal glands ofnymphs and 21 in metathoracic glands of adults), and six in the sternal glandular epithelium of the males. The biological function of the glandular secretions and of their identified compounds were investigated and are discussed.
Learning can be detrimental for a parasitic wasp
2021
Animals have evolved the capacity to learn, and the conventional view is that learning allows individuals to improve foraging decisions. The parasitoid Telenomus podisi has been shown to parasitize eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of its coevolved host, Podisus maculiventris, but the parasitoid cannot complete its development in the exotic species. We hypothesized that T. podisi learns to exploit cues from this non-coevolved species, thereby increasing unsuccessful parasitism rates. We conducted bioassays to compare the responses of naïve vs. experienced parasitoids on chemical footprints left by one of the two host species. Both naïve and experienced …
Kel1 is a phosphorylation-regulated noise suppressor of the pheromone signaling pathway.
2021
Abstract Mechanisms have evolved that allow cells to detect signals and generate an appropriate response. The accuracy of these responses relies on the ability of cells to discriminate between signal and noise. How cells filter noise in signaling pathways is not well understood. We have analyzed noise suppression in the yeast pheromone signaling pathway. By combining synthetic genetic array screening, mass spectrometry and single-cell time-resolved microscopy, we discovered that the poorly characterized protein Kel1 serves as a major noise suppressor of the pathway. At the molecular level, Kel1 suppresses spontaneous activation of the pheromone response by inhibiting membrane recruitment of…
Response of the Saccharomyces cerevisiae Mpk1 Mitogen-Activated Protein Kinase Pathway to Increases in Internal Turgor Pressure Caused by Loss of Ppz…
2004
ABSTRACT The Mpk1 pathway of Saccharomyces cerevisiae is a key determinant of cell wall integrity. A genetic link between the Mpk1 kinase and the Ppz phosphatases has been reported, but the nature of this connection was unclear. Recently, the Ppz phosphatases were shown to be regulators of K + and pH homeostasis. Here, we demonstrate that Ppz-deficient strains display increased steady-state K + levels and sensitivity to increased KCl concentrations. Given these observations and the fact that K + is the major determinant of intracellular turgor pressure, we reasoned that the connection between PPZ1 and - 2 and MPK1 was due to the combination of increased internal turgor pressure in Ppz-defic…
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…
Sexual communication in the egg parasitoid Trissolcus brochymenae
2009
The males of the egg parasitoid Trissolcus brochymenae (Hymenoptera Scelionidae) exploit a short range pheromone for recognition of the other gender. To evaluate the role of this pheromone, the behavior of virgin males has been studied in closed arena when exposed to the following cues: 1) virgin females (alive, dead "washed" with solvents, dead" unwashed"); 2) dissected and re-assembled virgin females (females dissected into head, mesosoma, and gaster, then reassembled using two solvent "washed" parts and an "unwashed” part, or "unwashed" legs assembled with entire" washed" body); 3) "washed" females treated with acetone extracts (of virgin females and of legs). Males antennate and mount v…
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 oil composition of the fruits of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae – Periplocoideae)
2011
The essential oil of the fruits of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae) from Lampedusa Island was obtained by hydrodistillation and its composition was analysed. The analyses allowed the identification and quantification of 64 volatile compounds belonging to different classes. The most abundant compounds were nonacosane, heptacosane, hentriacontane and δ-cadinene. Among the volatile compounds identified in the fruits of P. laevigata subsp. angustifolia, 31 are present in other taxa of Apocynaceae, 19 have antimicrobial activity and four are pheromones for the butterfly Danaus chrysippus. The possible ecological role of the volatile compounds found i…
Attracted or repelled?--a matter of two neurons, one pheromone binding protein, and a chiral center.
1998
Abstract Two species of scarab beetles, the Osaka beetle (Anomala osakana) and the Japanese beetle (Popillia japonica), utilize the opposite enantiomers of japonilure, (Z)-5-(1-decenyl)oxacyclopentan-2-one, as their sex pheromones. Each species produces only one of the enantiomers that functions as its own sex pheromone and as a very strong behavioral antagonist for the other species. Using an integrated approach we tested whether the discrimination of these two opposite signals is due to selective filtering by pheromone binding proteins or whether it originates in the specificity of ligand–receptor interactions. We found that the antennae of each of these two scarab species contain only 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 …