Feminization and the collapse of haplodiploidy in an asexual parasitoid wasp harboring the bacterial symbiont Cardinium.

Cardinium is a bacterial symbiont infecting many species of arthropods, and is associated with manipulation of host reproduction. Cardinium is the causal agent of asexual reproduction, or thelytoky, in the chalcidoid parasitoid wasp Encarsia hispida. Feeding antibiotics to the infected adult females results in uninfected male offspring. Here, we show that these males are diploid. Diploid males are extremely unusual in the large hymenopteran superfamily Chalcidoidea, and, to our knowledge, have never before been associated with symbiont infection in this group. These findings indicate that at least in E. hispida, diploidy restoration is a necessary condition but not sufficient to elicit female development. Cardinium is required to feminize diploid male embryos and thus must interact with elements of the host sex determination system. In addition, our data suggest that Cardinium is necessary for the fertility of E. hispida; antibiotic curing of Cardinium reduces offspring production of adult females.

Development of improved molecular methods for the detection of deformed wing virus (DWV) in honeybees (Apis mellifera L.) and mites ( Varroa destructor Oud.).

A simple and rapid method for the extraction of total nucleic acid from honeybee and mite, useful either as template for RT-PCR or in nucleic acids hybridization, was developed. Sensitivity of the methods were evaluated up to 10(9) and 10(6) dilution of TNAs extracted from a single honeybee, for reverse transcriptase polymerase chain reaction and molecular hybridization respectively. The two diagnostic methods developed could be useful for the study of the molecular biology and the pathology of DWV. For practical applications dot-blot hybridization could be used in order to study the incidence of DWV in honeybees populations. The method is enough sensitive, rapid and less affected by contamination problems compared to RT-PCR and thus it could be applied to the sanitary certification of honeybees and their products.

[Varroa mites in the apiaries of Campania region]. / Presenza e diffusione di Varroa negli alveari della Campania.

Mites in the genus Varroa are obligate ectoparasites of honey bee populations worldwide. Recent evidence from morphological, geographical, and especially genetic variation has spurred an important revision of Varroa taxonomy. Specifically, mitochondrial DNA (mtDNA) evidence suggests that the main mite pest on western honey bees (Apis mellifera) is not Varroa jacobsoni, as first described, but a distinct species now named Varroa destructor. Genetic markers also have been used to support a taxonomic basis for regional differences in how Varroa mites impact honey bees. Recent morphometric and molecular studies confirmed the presence of the species V. destructor also in the apiaries of the Campania region of southern Italy. In the three-year period 2001-2003 a survey was conducted in 118 municipalities of the five provinces of the Campania region in order to add data to the limited epidemiological information available regarding Varroa destructor in this zone. The level of infestation by the mite was assessed on a total of 521 apiaries (241 apiaries were inspected on 2001, 154 on 2002, and 126 on 2003). In each apiary, 100 comb cells were examined and in each province the level of infestation was calculated using the following formula: (number of Varroa specimens/number of open comb cells) x 100. In order to display the level of infestation, Geographical Information Systems were used in order to draw parasitological maps.

Major depression with mood-congruent psychotic features: a distinct diagnostic entity or a more severe subtype of depression?

The nosological status of major depression with mood-congruent psychotic features was explored by a cross-sectional demographic, clinical and biological assessment and a 7-year prospective follow-up of 2 samples of patients fulfilling, respectively, DSM-III criteria for this condition and for major depression without psychotic features. The 2 patient groups did not differ with respect to demographic and historical features, response to DST and outcome. The global severity of the index episode was greater in psychotics. All nonpsychotics and 69% of psychotics were treated with antidepressants alone or in combination with benzodiazepines, whereas the addition of neuroleptics was required only in 31% of psychotics. A tendency towards an interepisodic diagnostic stability was verified in nonpsychotics more than in psychotics, but was less pronounced than that reported by the authors advocating the nosological autonomy of delusional depression. These data support the view that major depression with mood-congruent psychotic features is not a distinct diagnostic entity, but rather a more severe depressive subtype.