Leucocytozoonosis in Canada geese in upper Michigan,. 1. Strain differences among geese from different localities.

Geographic variation in pathogenicity of Leucocytozoon simondi in Canada geese (Branta canadensis maxima) was investigated by exposing goslings to natural infection at three locations in the upper peninsula of Michigan. Examination of blood smears and tissue sections revealed two patterns of development. Hepatic schizogony and secondary megaloschizogony occurred in cells of the reticuloendothelial system, with round and elongate gametocytes, or only hepatic schizonts and round gametocytes. The evidence for strain differences in L. simondi and its implications in wildfowl management practices are discussed.

The distribution and biology of Austrosimulium pestilens, a serious biting-fly pest following flooding.

The distribution of A. pestilens is expanded with records from the southern Gulf of Carpentaria Rivers. The value of sampling specific adult resting sites for the assessment of host range and vector potential is recorded. The value of CO2 as an attractant and the truck trap, or modifications thereof, as a collector of A. pestilens is also demonstrated.

Penetration and survival of mesocercariae (Alaria spp.) in the mammalian eye.

A Canadian woman presented with a motile, intra-retinal worm, which by appearance and movement was strikingly similar to the mesocercaria of Alaria sp., a trematode from frogs. Using these mesocercariae and rabbits this study set out to establish 1) whether these mesocercariae can penetrate the cornea, 2) how long they might survive within the eye, and 3) what reaction is produced. It was found that some penetrated the cornea readily and, after injection, were capable of prolonged survival within the eye. Little overt reaction was produced though histologically the expected chronic inflammatory reaction with eosinophils occurred.