1938 Volume 8 Issue 2 Pages 95-112
The spore forms of the sooty moulds on sugar canes are extraordinarily diverse, not infrequently no less than six forms being found on the same leaf in Formosa. The fungi spread on the leaves infested with the aphid, Ceratovacuna lanigera ZEHNT., and appear to be closely related to those of India, Queensland and other countries. The results of the studies made on the cultures originated from a single spore of each form reveal that the moulds on the sugar cane can be separated into at least three different species, namely, olivaceous, black, and brownish sooty moulds.
1. The olivaceous sooty mould, Fumago vagans PERS., fine powdery; thin subiculum generally on the upper surface of the leaves. Conidiophores simple, erect, more or less geniculate at the upper part, yellowish brown to dark brown, 3-16-septate, 22-16 × 3.6-6μ. Conidia acropleurogenous, catenulate in short chains, ellipsoid, ovoid or oblong, continuous or 1-septate, rarely 2-septate, light fuscous to dark olive, 5-16 × 3-6.5μ, rarely up to 23 μ. Gemma-like chlamydospores irregularly ellipsoid, ovoid, oblong or subglobose, generally 2 to several muriform-septate, or sarcinaeform, olivaceous brown to dark brown, thick-walled, 7-23 × 5-19μ.