The effect of different proportions of males and females over the Chrysomya albiceps (Wiedemann 1819) (Diptera, calliphoridae) biotic potential and longevity under laboratory conditions.

Chrysomya albiceps specimens were derived from colonies kept under laboratory conditions. The oviposition period, total number of eggs-mass and the weight of the eggs-mass (average/female) presented significant differences between colonies regarding the sexual ratio of 1 male/1 female (situation 1), when compared to the other ratios (1 male/3 female, situation II), (1 male/5 female, situation III), (3 male/1 female, situation IV) and (5 male/1 female, situation V). It was ascertained that the increase in the proportion of females, resulted in higher weight and greater number of ovipositions and lengthening of the period of oviposition, leads to a decrease in their lifespan.

[Geopolitical distribution of the occurrence of Fasciola hepatica in Santa Catarina State, Brazil]. / Dispersão geopolítica da ocorrência de Fasciola hepatica no Estado de Santa Catarina, Brasil.

During 12 years feces samples from cows, water buffaloes, sheeps and goats were examined by sequential tamis filtration to show the occurrence of Fasciola hepatica eggs. The material came from 129 municipalities of Santa Catarina State, and 5 g of feces per animal were examined. The occurrence of F. hepatica was confirmed in 64.82% of the municipalities. Considering the host, F. hepatica was confirmed in goats from Florianópolis, São José, São João Batista and Guaramirim municipalities; in sheep from Brusque, Pomerode, Palhoça and São José; in water buffaloes from 9 and in cows from 86 municipalities. For this study, 13,762 feces samples were examined and in 3,814 the presence of eggs of F. hepatica was demonstrated. The percentage of occurrence for host species was 27.86 in cows, 24.72 in water buffaloes, 16.92 in sheep and 15.66 in goats. By the results it was demonstrated that Itajaí Valley at Southeast Hidrographic Basin, in Santa Catarina State is an endemic area of F. hepatica, even though Uruguai Hidrographic Basin was not referred as a geographical record for this parasite.

Epidemiology of Fasciola hepatica infection in the Paraíba River Valley, São Paulo, Brasil.

The study revealed that although Lymnaea columella and Stenophysa marmorata were found in the same habitat, only L. columella harbored intramolluscan stages of F. hepatica. The population density of L. columella cyclically decreased between September and February, and increased from March to September. The drought that occurred between June and November 1981 dramatically reduced the number of snails collected. Larger snails were collected in March-July and November-December, while the smaller snails were collected in January-February and August-October, suggesting that there may be two generations of L. columella per year. The highest prevalence levels of infection in L. columella were: first year, June 8.82%, September 9.09% and October 10.52%; second year, March 6.25% and April 6.89%; third year, July 7.69%, August 10.25%, April 17.91% and May 13.91%. Results obtained with tracer sheep showed that the largest numbers of metacercariae were on pasture between June and October, and between March and April, but the infection was present during most of the year.