RESUMEN
Geographical distribution and abundance of the pupae of six blackfly species of medical and veterinary concern were studied in eastern Spain according to three different sets of explanatory variables including in-stream variables, both (i) abiotic (i.e., physicochemical) and (ii) biotic (i.e., richness and abundance of either taxonomically or ecologically close related taxa), as well as (iii) meteorological and landscape variables. The results showed specific habitat requirements for pupation in Simulium (Boophthora) erythrocephalum (De Geer, 1776) and Simulium (Wilhelmia) equinum (Linnaeus, 1758), two of the six species studied regarding elevation and temperature. While the rest of the species showed a certain degree of ecological overlap, co-occurrence was in general low, which suggested that antagonistic biotic factors may be important in structuring blackfly assemblages. In effect, biotic predictors explained a high proportion (50%-70%) of the variability in the abundance of the pupae of the most generalist blackfly species, although further studies are needed to disentangle the sign of interspecific interactions. At the landscape level, S. (W.) equinum and S. (W.) pseudequinum Séguy, 1921 breeding habitats were associated with the presence of pig farms, and S. (Simulium) reptans (Linnaeus, 1758) and S. (B.) erythrocephalum with the presence of cattle.
Asunto(s)
Simuliidae , Animales , Bovinos , Ecosistema , Pupa , España , Porcinos , TemperaturaRESUMEN
Recent autochtonous malaria cases which occurred in Spain, France, Greece or Italy have shown the need to delve into the knowledge of potential influence of tropical diseases in Southern Europe. The malariogenic potential of a formerly endemic area of Spain was analyzed in present manuscript according to the epidemiological parameters of receptivity, infectivity and vulnerability. During a five years period (2005-2009) comprehensive larval surveys of anophelines and continuous analysis of imported malaria cases were conducted in a study region of about 23 260 km². The next seven potential malaria vectors were collected: Anopheles algeriensis, Anopheles atroparvus, Anopheles claviger, Anopheles maculipennis, Anopheles marteri, Anopheles petragnani and Anopheles plumbeus. The entomological results conclude that malaria receptivity is still high in different rural and hinterland regions where it is possible to find high densities of An. atroparvus. Moreover An. algeriensis was also commonly found breeding in irrigation channels surrounding urban areas. Although receptivity is relevant in much of the study area, fortunately the vulnerability of the territory is very low. In conclusion, despite our data together with current socio-economic and sanitary conditions of Spain indicate a relatively low malariogenic potential, we must maintain the entomological and epidemiological vigilance in order to prevent the potential appearance of indigenous malaria cases. Therefore, the present Spanish situation can be described as what malariologists of the first half of the last century would have called "anophelism without malaria."
Asunto(s)
Anopheles/crecimiento & desarrollo , Vectores de Enfermedades , Malaria/epidemiología , Animales , Anopheles/clasificación , Femenino , Larva/crecimiento & desarrollo , España/epidemiologíaRESUMEN
The handling of the vegetation cover is known as one of the major cultural strategies in pest control. This study shows the interactions between Liriomyza and their hosts-plants found in three natural parks from the Community of Valencia for 6 of the 13 Liriomyza species (Diptera: Agromyzidae) cited from Spain as potential pests for agriculture: L. bryoniae (Kaltenbach, 1858), L. cicerina (Rondani, 1875), L. congesta (Becker, 1903), L. strigato (Meigen, 1830), L. brassicae (Riley, 1884), and L. trifolii (Burgess in Comstock, 1880). Three new interactions for science to L. brassicae and L. trifolii are recorded. The importance of these interactions lies in the potential of being able to act as plant reservoirs for development of pest species alternative to crops. Distribution of Lirfomyza species by botanical families and species, including the study of beta diversity for the studied biotopes, are showed.
Asunto(s)
Dípteros/patogenicidad , Plantas/parasitología , Animales , Biodiversidad , Dípteros/genética , Dípteros/crecimiento & desarrollo , Ecosistema , Francia , Variación Genética , Región Mediterránea , Densidad de Población , España , Especificidad de la EspecieRESUMEN
The ability of Bacillus thuringiensis to produce septicaemia in Periplaneta americana and Blatta orientalis has been investigated. Spores and crystals from several wild-type strains as well as spores of a B. thuringiensis crystal-deficient mutant, were first orally administrated at high doses, and no significant mortality was recorded. Intrathoracic injection of spore suspensions in P. americana revealed that this species is not very susceptible to B. thuringiensis spores. B. orientalis, by contrast, was found to be very susceptible to B. thuringiensis, with a LD(50) of about 35,000 spores, that is similar to that reported on Lepidoptera challenged with parenterally injected B. thuringiensis.