Specialization in Sphaerotheca fuliginea (SCHLECHT.) POLL. parasitic on various plants in Formosa was studied by inoculation experiments as well as by comparing the morphological characters of the conidia. So far as the present experiments are concerned, the following six biological species can be distinguished inter se.
A. Conidia with an average length of 29μ
1. Parasitic on Balsam (Impatiens Balsamina)
B. Conidia with an average length of 32μ
a. Conidia with an average width of 18μ
2. Parasitic on Cucurbitaceae
3. Parasitic on Lactuca indica var. dracoglossa and related species
b. Conidia with an average width of 20μ
4. Parasitic on egg plant (Solanum Melongena)
5. Parasitic on Hibiscus mutabilis
C. Conidia with an average length of 36μ
6. Parasitic on Emilia sonchifolia
