ABSTRACT
Diaphorina citri Kuwayama is the vector of the pathogenic bacteria Candidatus Liberibacter spp., the causative agent of Huanglongbing (HLB), the most serious disease of citrus worldwide. Because predatory insects have been historically neglected in biological control programs for D. citri, the impact of generalist predators on D. citri population densities is little understood. A useful tool to evaluate the dynamics of predator-prey interactions is molecular analysis of predators' gut content. We constructed a specific molecular marker to detect D. citri DNA in the gut content of predator insects, for use in estimating the predation rate of field-collected predators in citrus orchards on D. citri. Bioassays of the DNA half-life detection time were carried out with two predatory species, the ladybird beetle Hippodamia convergens Guérin-Méneville and the lacewing Chrysoperla externa (Hagen). The D. citri DNA half-life detection time (DT50) was 6.11 h for H. convergens and 5.46 h for C. externa. One hundred and seven field-collected predators were used for gut-content analysis (52 larvae/adults of ladybirds and 55 larvae of lacewings). The assays showed that 17.3% of ladybirds but no lacewings tested positive for D. citri DNA. These results show that generalist predators can contribute to biological control of D. citri and should be considered for use in pest management programs in citrus orchards.
Subject(s)
Coleoptera/chemistry , DNA/analysis , Gastrointestinal Contents/chemistry , Hemiptera/genetics , Neoptera/chemistry , Animals , Citrus , Genetic Markers , Half-Life , Larva/chemistry , Pest Control, Biological , Population Density , Predatory BehaviorABSTRACT
In recent years education programmes for adults have been developed focusing on improving patient self-management. The aim of this study was to evaluate the efficacy of two different educational programmes on asthma at one year (short-term efficacy) and three years (long-term efficacy). Changes in pulmonary function (FEV1), knowledge of disease and skill concerning inhalation technique were evaluated to determine the efficacy of the educational programme. Forty patients were randomly assigned to the two different educational programmes. Twenty subjects (mean age 49 +/- 11 yrs; FEV1 79% +/- 15 of predicted) were assigned, to a basic educational programme, while the others (mean age 44 +/- 11 yrs; FEV1 79% +/- 14 of predicted) were assigned to an "asthma school" programme. In both "basic" and "asthma school" groups there was a significant increase from baseline to one year (p < 0.05) and three years (p < 0.05) in FEV1, number of correct answers to the knowledge questionnaire, and number of correct steps during the inhalation procedure. No significant differences were found between the two groups at baseline, one year and three years for all three variables studied. This study confirms that both educational programmes determine in asthmatics an improvement in lung function, knowledge of disease and skill for inhalation technique at one year and three years following commencement of the programme. A "basic" educational programme is as effective as an "asthma school" one.