سیما زنگنه - Researcher, Department of Botany, Iranian Research Institute of Plant Protection, P.O. Box ۱۴۵۴, Tehran ۱۹۳۹۵, Iran (E-mail: simazangeneh@yahoo.com)
شهرام فرخی - Assistant Prof., Department of Biological Control, Iranian Research Institute of Plant Protection, P.O. Box ۱۴۵۴, Tehran ۱۹۳۹۵, Iran

After heavy rainfalls in late Apr. of ۲۰۱۰ in Tehran, an epizootic occurred amongst hoverflies (Eupeodes corollae Fabricius) population in green spaces of Iranian Research Institute of Plant Protection, caused by an entomopathogenic fungus. Infected flies fixed to the upper parts of whitetop (Lepidium draba L.) and small tumbleweed mustard (Sisymbrium loeslii L.) plants with their proboscis and clasped legs, their head went downwards and their wings spread latero-dorsally. The fungus produced conidiophores, which ruptured the host cuticle at the intersegmental membranes, resulting in cream-coloured mycelial bands on the abdomen or in a complete cover of the dorsal abdomen. They forcibley discharged around primary conidia, many of them landed on wings and on the surface of the cadaver.