A zygosporic stage of the Harpellales (Trichomycetes, Zygomycota) associated with simuliid egg massesâ€

The presence of an ovarian stage in the life-cycle of the Harpellales observed during an ecological study of the Trichomycetes associated with simuliid egg masses in the UK is reported. The ovarian stage was observed to develop zygospores that are morphologically similar to those produced by the midgut species Harpella melusinae in the host larva. Morphological characteristics and the possible developmental stages of this propagule are described using scanning electron microscopy. The discovery of this stage suggests that chlamydospores may play an important role in the life-cycle of the Trichomycetes.