RESUMO
We evaluated the influence of temperature, rainfall, and host relative abundance on Rogenhofera bonaerensis (Diptera, Cuterebridae) parasitism prevalence in shrubland mouse (Akodon molinae) populations in central Argentina, from February 1983 to December 1987. Parasitism did not vary significantly with host age: juvenile-subadults (32%), adults (26%), and old adults (29%). Females were more frequently parasitized (36%) than were males (20%). There was no correlation between parasitism and reproductive activity. Infested hosts were recorded most commonly in summer (January to March, 19%), and in fall (April to June, 30%). During the dry season, July through November, cuterebrid parasitism averaged only 3%. The monthly prevalence of parasitism throughout the year was not associated either with monthly precipitation nor with mean monthly temperature at the time of sampling. But a 2 to 3 month time-lag effect of both climatic variables on parasitism was recorded. Bot fly prevalence was correlated to an index of host density. We propose climate and host availability as important factors affecting bot fly parasitism in the semiarid shrubland of central Argentina.
Assuntos
Arvicolinae/parasitologia , Dípteros/crescimento & desenvolvimento , Miíase/veterinária , Animais , Argentina/epidemiologia , Feminino , Interações Hospedeiro-Parasita , Larva/crescimento & desenvolvimento , Masculino , Miíase/epidemiologia , Prevalência , Chuva , Análise de Regressão , Estações do Ano , Fatores Sexuais , TemperaturaRESUMO
Seasonality and impact of parasitism by the larvae of Rogenhofera bonaerensis (Diptera: Cuterebridae) in pampean grassland mouse (Akodon azarae, Rodentia, Cricetidae) populations were studied in grasslands and cropfield borders near Diego Gaynor (Buenos Aires Province, Argentina), from November 1985 to December 1986. Trapped mice infections ranged from one larva (77%) to four (4%) per host; larvae occurred on tails (75.7%), backs (17.1%), thighs (5.7%), and abdomen (1.4%). Prevalence of larvae occurred in late spring (November and December) (35%), and in fall (March to June) (20%), with a peak of 25% during April and May. In spring these larvae affected 46% of resident and 19% of transient individuals; however, no differences were found between residents and transients in spring or fall. There was no significant relationship between mouse population density and prevalence of parasitism (r = -0.56). The annual percentage of infected rodents changed with age (body size classes): adults (37%) greater than subadults (25%) greater than juveniles (16%); with no differences between the sexes. Similar results were recorded in the spring, but there were no differences in the fall. Significant differences were not detected between stable (22% infected) and disturbed habitats (14% infected). During winter uninfected mice survived better than those infected during the previous fall. In contrast, the summer survival among spring infected mice and noninfected mice was similar. Parasitism showed no effects on reproductive activity and on home range size. Larvae showed strong host specificity for A. azarae (99%). Only one case was recorded in the long-tailed mouse (Oligoryzomys flavescens), and none in the white paunch mouse (Calomys laucha), both species sympatric with A. azarae.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Arvicolinae/parasitologia , Miíase/veterinária , Doenças dos Roedores/epidemiologia , Abdome/parasitologia , Fatores Etários , Análise de Variância , Animais , Argentina/epidemiologia , Dorso/parasitologia , Miíase/epidemiologia , Prevalência , Reprodução , Estações do Ano , Cauda/parasitologia , Coxa da Perna/parasitologiaAssuntos
Agricultura , Ecologia , Febre Hemorrágica Americana/prevenção & controle , Controle de Roedores , Animais , Argentina , Humanos , Densidade Demográfica , Roedores , Glycine max , Triticum , Zea maysRESUMO
En este trabajo se analizo la variacion de las densidades de especies de roedores segun el tipo de cultivo y manejo agricola.Comparando campos de maiz y soja, a termino, se observo que en los primeros la densidad es mayor que en los segundos, mientras que esta es aun menor en los campos de cultivo invernal, excepto durante su rastrojo. Los campos de maiz que fueron pastoreados previamente a su siembra muestran, a termino menor densidad de roedores que los que no fueron pastoreados, mientras que en los campos de soja la siembra con maquina de trigo tiene un efecto similar. El efecto de los distintos cultivos y manejos varia segun la especie de roedor considerada, siendo las del genero Calomys las que muestran mayor variacion. Debido a que dichas especies son las de mayor importancia epidemiologica, se sugiere, como una primera aproximacion al control ecologico de la FHA, la siembra de soja en lugar de maiz en el area endemica y zonas aledanas, asi como el pastoreo intensivo de los campos previamente a la siembra
Assuntos
Humanos , Animais , Agricultura , Ecologia , Febre Hemorrágica Americana , Controle de Roedores , ArgentinaRESUMO
En este trabajo se analizo la variacion de las densidades de especies de roedores segun el tipo de cultivo y manejo agricola.Comparando campos de maiz y soja, a termino, se observo que en los primeros la densidad es mayor que en los segundos, mientras que esta es aun menor en los campos de cultivo invernal, excepto durante su rastrojo. Los campos de maiz que fueron pastoreados previamente a su siembra muestran, a termino menor densidad de roedores que los que no fueron pastoreados, mientras que en los campos de soja la siembra con maquina de trigo tiene un efecto similar. El efecto de los distintos cultivos y manejos varia segun la especie de roedor considerada, siendo las del genero Calomys las que muestran mayor variacion. Debido a que dichas especies son las de mayor importancia epidemiologica, se sugiere, como una primera aproximacion al control ecologico de la FHA, la siembra de soja en lugar de maiz en el area endemica y zonas aledanas, asi como el pastoreo intensivo de los campos previamente a la siembra