Search results for "Systematics"
showing 10 items of 6702 documents
New distributional data on <em>Haemogregarina stepanowi</em> (Apicomplexa) and <em>Placobdella costata</em> (Hirudinea) paras…
2021
The host-parasite system “Emys trinacris – Placobdella costata – Haemogregarina stepanowi” is known for Sicily, but scarce information is available to date about the distribution of the two parasites on the island. Therefore, an extensive sampling effort through visual census and collection and analysis of blood smears of the endemic Sicilian pond turtle E. trinacris was carried out in 46 water bodies scattered throughout mainland Sicily. Our findings revealed that the distribution of both parasites is limited to the Nebrodi area, where the infection of H. stepanowi has shown a high incidence on the local turtle populations. Our data suggest no correlation between the current distribution o…
The effect of host mycorrhizal status on host plant-parasitic plant interactions
2001
Two pot experiments were conducted to examine three-level interactions between host plants, mycorrhizal fungi and parasitic plants. In a greenhouse experiment, Poa annua plants were grown in the presence or absence of an AM fungus (either Glomus lamellosum V43a or G. mosseae BEG29) and in the presence or absence of a root hemiparasitic plant (Odontites vulgaris). In a laboratory experiment, mycorrhizal infection (Glomus claroideum BEG31) of Trifolium pratense host plants (mycorrhizal versus non-mycorrhizal) was combined with hemiparasite infection (Rhinanthus serotinus) of the host (parasitized versus non-parasitized). Infection with the two species of Glomus had no significant effect on th…
Arthropod-induced neoplastic formations on trees change photosynthetic pigment levels and oxidative enzyme activities
2005
Abstract In order to test the hypothesis that arthropod-induced neoplastic formations on trees affect biochemical characteristics of both the newly formed galls and host plant tissues, biochemical characteristics with a possible adaptive role were determined in nine gall-former–host tree combinations. Photosynthetic pigments, extractable protein content, and oxidative enzyme activities were determined in gall tissues, leaf tissues of galled leaves, and leaves on ungalled tree branches. Neoplastic tissues were characterized by a low content of photosynthetic pigments, decreased chlorophyll a/b ratio, lower extractable protein content, and decreased activities of peroxidase and polyphenol oxi…
Responses of Metaphycus sp. nr. flavus to semiochemicals released from a scale host, Coccus hesperidum
2004
Metaphycus sp. nr. flavus (Encyrtidae: Hymenoptera) is a parasitoid species collected from the Mediterranean region which lays its eggs in the immature stages of several economically important soft scale insects (Hemiptera: Coccidae), including brown soft scale, Coccus hesperidum L. (= host insect). Preliminary tests suggested that the parasitoid is most successful in producing offspring when it oviposits in the younger stages of brown soft scale. In Y-olfactometer bioassays measuring wasp choices and residence times, naïve parasitoids were significantly more attracted to yucca leaves infested with 26, 27, or 28 d-old scale than to uninfested leaves, whereas leaves with older (29-30 d-old) …
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…
Staphylococcus prevails in the skin microbiota of long-term immunodeficient mice
2012
Summary Host-commensal relationships in the skin are a complex system governed by variables related to the host, the bacteria and the environment. A disruption of this system may lead to new steady states, which, in turn, may lead to disease. We have studied one such disruption by characterizing the skin micro- biota in healthy and immunodepressed (ID) mice. A detailed anatomopathological study failed to reveal any difference between the skin of healthy and ID mice. We sequenced the 16S rDNA V1-V2 gene region to saturation in 10 healthy and 10 ID 8 week- old mice, and found than all of the healthy and two of the ID mice had bacterial communities that were similar in composition to that of h…
Female choice for male drumming in the wolf spiderHygrolycosa rubrofasciata
1997
Mate preferences in invertebrates have usually been studied with simultaneous choice exper- iments alone, which allows eVective detection of any preferences but does not tell much about the strength of inter-sexual selection. Under natural conditions females frequently have to rely on sequential choice, and choosy females may incur opportunity and direct costs such as loss of time when they reject a male. Female preference in the wolf spider Hygrolycosa rubrofasciata for two components of male courtship signalling, rate and volume, was investigated. Both of these characteristics were tested with a sequential choice set-up and the eVect of volume also with a simultaneous choice method. Femal…
Immunological and ultrastructural characterization of spirotrichonymphid flagellates from Reticulitermes grassei and R. flavipes (syn. R. santonensis…
2006
AbstractFive species of spirotrichonymphids representing three genera have been studied by light and immunofluorescence microscopy, and by transmission electron microscopy. The genus Spirotrichonympha, represented by S. flagellata from Reticulitermes grassei, is characterized by a compound axostyle composed of several fibers or subaxostyles. The genus Spironympha, represented by S. kofoidi from Reticulitermes flavipes (syn. R. santonensis) and by the two new species S. verticis and S. lanceata, is characterized by flagellar lines restricted to the anterior area and a simple, tubular axostyle. Spironympha verticis and S. lanceata are mainly distinguished by ultrastructural details of their f…
Three NewAdelphenaldisSpecies (Hymenoptera: Braconidae: Alysiinae) from Africa, with First Descriptions of the Female ofA. subsurrectionis(Fischer) a…
2014
Three new species of the genus Adelphenaldis from Africa (including Madagascar) are described: Adelphenaldis capensis sp. n., A. mesoafricanus sp. n., and A. noyesi sp. n. The female of A. subsurrectionis (Fischer, 2003) and the male of A. claricornis (Fischer, 1993) are recorded for the first time and described.
Morphological and molecular evidence for interspecific hybridisation in the introduced African genusCrassocephalum(Asteraceae: Senecioneae) in Asia
2009
Abstract The genus Crassocephalum in Asia, introduced there from Africa, was examined by extensive field work, herbarium studies, analyses of pollen and seed fertility, chromosome counts and ITS and trnL‐F sequencing. We found that Crassocephalum in Asia comprises two species and their interspecific hybrid. The two species are C. crepidioides (Benth.) S. Moore and C. rubens (Juss. ex Jacq.) S. Moore, of which the latter is a new record for Asia (north Thailand). The hybrid between these two species in north Thailand originated from a cross between C. crepidioides (2n = 40) as female and C. rubens (2n = 40) as male parent.