O. A. Johannsen

No biography available.

Works (11)

Cover of The fungus gnats of North America, part III

The fungus gnats of North America, part III

Cover of Aquatic nematocerous diptera. (I)

Aquatic nematocerous diptera. (I)

Cover of Embryology of insects and myriapods

Embryology of insects and myriapods

Cover of The fungus gnats of North America, part IV

The fungus gnats of North America, part IV

Cover of Apple tree insects of Maine

Apple tree insects of Maine

Cover of The fungus gnats of North America, part I

The fungus gnats of North America, part I

Cover of Spruce bud worm and spruce leaf miners

Spruce bud worm and spruce leaf miners

Cover of Aquatic diptera

Aquatic diptera

Cover of Potato flea-beetle (Epitrix cucumeris)

Potato flea-beetle (Epitrix cucumeris)

Cover of The fungus gnats of North America, part II

The fungus gnats of North America, part II

Cover of Insect notes for 1909

Insect notes for 1909