Sporulation by Entomophthora schizophorae (Zygomycetes: Entomophthorales) from housefly cadavers and the persistence of primary conidia at constant temperatures and relative humidities.

The duration of discharge of Entomophthora schizophorae (Zygomycetes: Entomophthorales) conidia from house fly (Musca domestica, Diptera) cadavers was measured at 7, 18, and 25 degrees C. The higher the temperature, the shorter the duration of conidia discharge. Significantly more conidia were produced per cadaver at 7 degrees C over a period of 120 h than at 18 and 25 degrees C. At 25 degrees C, the initial discharge over the first 10 h was much larger than at the other temperatures, and at 7 degrees C, no peak in discharge was observed. The persistence of E. schizophorae primary conidia was measured on fabricated non-host surfaces typically found in stables (straw, wood, plaster, and glass) at 7, 18, and 25 degrees C or constant relative humidities of 45, 65, and 85%. Persistence, as measured by the subsequent ability to infect flies, was usually only a few days and depended on the temperature and type of surface. It was greatest on straw, followed by wood, glass, and plaster, and at 7 degrees C, followed by 18 and 25 degrees C. Limited transmission took place between flies exposed to conidia and previously unexposed mates.

Entomopathogenic fungi associated with Ixodes ricinus ticks.

The objective of this study was to demonstrate the occurrence of entomopathogenic fungi on Ixodes ricinus ticks in relation to the tick stage, engorgement and season. Ticks were collected from the vegetation, from small rodents and from deer. All entomopathogenic fungi found belonged to the Hyphomycetes. Paecilomyces farinosus and Verticillium lecanii were the predominant species. Other species, found only on engorged females were: Beauveria bassiana, B. brongniartii, P. fumosoroseus and V. aranearum. Eight out of 1833 ticks collected from the vegetation and three out of 269 engorged nymphs were infected with fungi. Thirty-three out of 149 engorged females were infected, whereas males and engorged larvae were not infected. Throughout the season, a significantly higher proportion of ticks collected in autumn were infected. Entomopathogenic fungi may have a significant impact on the size of the I. ricinus population, since females were the most frequently infected stage.