Contemporary adaptation of plant feeding insects to introduced hosts provides clear cases of ecologically based population divergence. In most cases the mechanisms permitting rapid differentiation are not well known. Here we study morphological and genetic variation associated with recent shifts by the Australian soapberry bug Leptocoris tagalicus onto two naturalized Neotropical balloon vines, Cardiospermum halicacabum and C.
View Article and Find Full Text PDFJ Am Mosq Control Assoc
September 2006
para-Menthane-3,8-diol(PMD) is a monoterpene spent product of the distillation of leaves of the Australian lemon-scented gum tree (updated nomenclature Corymbia citriodora ssp. citriodora). In April 2005, the U.
View Article and Find Full Text PDFJ Am Mosq Control Assoc
September 2006
We tested a lemon eucalyptus-based repellent against the biting midge Leptoconops carteri Hoffman in the Central Valley of California. This relatively new active ingredient has demonstrated high efficacy in a number of studies with mosquitoes. Ten subjects tested spray and lotion formulations on 2 consecutive days, along with a deet-positive control and an untreated control, with 6 h of continuous exposure per treatment.
View Article and Find Full Text PDFObjective: To develop and use a sensitive molecular assay for detecting the phospholipase D (PLD) exotoxin gene of Corynebacterium pseudotuberculosis in an attempt to identify insect vectors that may be important in transmission of clinical disease in horses.
Sample Population: 2,621 flies of various species.
Procedure: A real-time polymerase chain reaction (PCR)-based fluorogenic 5' nuclease (TaqMan) system (ie, TaqMan PCR assay) was developed for the detection of the PLD gene in insects.
Reported are the results of a multicentre study involving 40 laboratories that was carried out in France to assess all the currently available methods used for the serodiagnosis of toxoplasmosis. For this purpose 10 batches of control sera were prepared with titres in the range 0-260 IU per ml. These sera were tested in nine laboratories using immunofluorescence methods; in three laboratories using dye tests; in forty laboratories using enzyme-linked immunosorbent assay; in four laboratories using direct agglutination and haemagglutination; in seven laboratories using the high-sensitivity IgG agglutination test; and in three laboratories using the latex agglutination test.
View Article and Find Full Text PDFEur J Clin Microbiol Infect Dis
January 1996
One hundred twenty-nine European laboratories participated in a collaborative, multicentre study designed to evaluate the overall reliability of different serological techniques for diagnosis of Toxoplasma gondii infection. Five freeze-dried reference sera were distributed to each laboratory, each of which analysed the sera with its routine methods. The enzyme-linked immunosorbent assay was the technique used most frequently, followed by the immunofluorescent antibody technique.
View Article and Find Full Text PDFParasitism has far-reaching implications not only for the ecology and evolution of species but also for conservation. The effects of blood-feeding ectoparasites on colonially nesting bird species have been wodely studied, but recent surprising reports show that solitarily nesting species are also commonly attacked, mainly by the larvae of flies. Most bird species are solitary nesters; as their habitats are increasingly fragmented, how will the potential for such parasitism be affected? One example is that of the endangered Puerto Rican parrot (Amazona vittata), in which habitat changes have introduced a deadly parasitic fly species in a complex and unpredicted manner.
View Article and Find Full Text PDFIn an effort to understand the forces shaping evolution of regulatory genes and patterns, we have compared data on interspecific differences in enzyme expression patterns among the rapidly evolving Hawaiian picture-winged Drosophila to similar data on the more conservative virilis species group. Divergence of regulatory patterns is significantly more common in the former group, but cause and effect are difficult to discern. Random fixation of regulatory variants in small populations and/or during speciation may be somewhat more likely than divergence driven by selection.
View Article and Find Full Text PDFIn May 1988, ten juvenile birds, not yet ready to fledge, jumped to their death from a colony of the purple martin, Progne subis near Okeechobee City, Florida. The martin house and nestlings were found to be infested with ectoparasitic Oeciacus vicarius Horvath, the cliff swallow bug, not previously reported from Florida. This ectoparasite infestation apparently led to early abandonment of two houses by the adult martins.
View Article and Find Full Text PDFThe association of immature ixodid ticks, several species of rodents, and the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, was studied in two habitats in northern California in spring and summer 1985 and year-round in 1986. A total of 428 rodents were collected from ecotonal chaparral and a woodland-grass-rock outcrop; the former habitat yielded six species, the latter three species. The deer mouse, Peromyscus maniculatus (Wagner), and the piñon mouse, P.
View Article and Find Full Text PDFThe relationship of immature western black-legged ticks, Ixodes pacificus Cooley and Kohls, to the western fence lizard, Sceloporus occidentalis Baird and Girard, and to the Lyme disease spirochete, Borrelia burgdorferi, was investigated in chaparral and woodland-grass habitats in northern California from 1984 to 1986. Immature ticks were found on lizards in spring and summer, but the prevalence and abundance of ticks on this host were considerably greater in spring. The peak of larval abundance preceded that of nymphs by several weeks, but there was considerable seasonal overlap between these parasitic stages.
View Article and Find Full Text PDFBull Acad Natl Med
April 1989
A study made among drug addicts in the Northern suburbs of Paris enables establishing a stabilisation of positive H.I.V.
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