The biocontrol nematode Phasmarhabditis hermaphrodita infects and increases mortality of Monadenia fidelis, a non-target terrestrial gastropod species endemic to the Pacific Northwest of North America, in laboratory conditions

Inundative biological control (biocontrol) efforts in pest management lead to the mass distribution of commercialized biocontrol agents. Many 'biocontrol gone awry' incidents have resulted in disastrous biodiversity impacts, leading to increased scrutiny of biocontrol efforts. The nematode Phasmarhabditis hermaphrodita is sold as a biocontrol agent on three continents and targets pest gastropods such as Deroceras reticulatum, the Grey Field Slug; P. hermaphrodita is not presently approved for use in the United States. Investigations into the potential for P. hermaphrodita to infect non-target gastropod species of conservation relevance, however, are limited. We examined the effects of three strains of P. hermaphrodita on mortality in Monadenia fidelis, the Pacific Sideband, a snail species endemic to the Pacific Northwest of North America, in laboratory conditions. Across a 71-day laboratory infectivity assay, snails exposed to each of the three nematode strains, each analyzed at two doses, experienced a mean 50% mortality by days 20-42. All nematode-treated snails were dead by the end of the study. By contrast, 30/30 water-control snails experienced no mortality. Nematodes killed smaller, juvenile-stage snails significantly faster than those in larger and more developmentally advanced hosts. Our results provide direct evidence that the biocontrol nematode P. hermaphrodita infects and kills M. fidelis, a non-target gastropod species endemic to the Pacific Northwest, in laboratory conditions. This study suggests that introduction of P. hermaphrodita to new ecosystems might negatively impact endemic gastropod biodiversity and advocates for further investigation of non-target effects, including in conditions closer to the natural environments of non-target species.

Primary and secondary prevention of alcoholism: emerging trends and research strategy

1. The theoretical and empirical value of a "level conceptualization in prevention" as proposed by the classical 'public health' model is challenged. 2. Although prevention should be related only to reduction of incidence of the disease (new cases), for various reasons the authors also include secondary prevention in the prevention of alcoholism. 3. Two main strategies are proposed in the prevention of alcoholism: (a) the global prevention directed to the population at large, and (b) the oriented or selective prevention directed to specific target groups (high risk groups). 4. In primary prevention a theoretical model, based on system theory "the ecogenetic wheel model" is proposed which tries to integrate the multidimensional (dependent variables), multifactorial and family approaches (independent variables) involved in alcoholic-related problems. 5. The biological predictors (chromosomal and biochemical markers) and psychological predictors to be used in the early detection of alcoholism are discussed. 6. Two theories are suggested for detection of biochemical markers: direct detection in naive subjects and indirect detection (activating theory) in subjects exposed to ethanol. 7. Secondary prevention could presently benefit from a "constellation" of clearly identified biological markers which would allow for the early detection of initial alcoholics. Screening programs could be implemented for selected target groups such as (a) occupational alcoholism programs, (b) programs for alcoholics' families, (c) programs for specific hospitalized patients and (d) alcohol programs related to traffic accidents.