A good illustration of wasp-mimicry is furnished by a large heteromerous beetle (Coloborhombus fasciatipennis) from Borneo which is remarkably like a large wasp (Mygnimia aviculus) from the same island.
They are heteromerous (figs.
In external form the heteromerous thallus presents the following modifications.
The typical heteromerous thallus shows on section a peripheral, thin and therefore transparent, layer, the cortical layer, and centrally a mass of denser tissue the so-called medullary layer, between these two layers is the algal zone or gonidial layer (figs.
- Section of Heteromerous Lichen Thallus.