The fungal past, present, and future: germination, ramification, and reproduction.

The history of observation and research on fungal pathogens of invertebrates dates back thousands of years. In the era before microscopes, fungi were visible to the naked eye and observation of them helped give birth to invertebrate pathology as a modern Weld of study. Early observations of disease in useful insects, the honey bee and the silkworm, included documentation of mycoses. Both general and particular historical aspects of fungal entomopathogens and their use as microbial control agents have been thoroughly reviewed by others (Alves, 1998; Boucias and Pendland, 1998; Hajek and St. Leger, 1994; McCoy et al., 1988; Roberts and St. Leger, 2004; Steinhaus, 1949, 1975; Tanada and Kaya, 1993). In this review, we will attempt a contemporary review of key advances in our knowledge of the many aspects of fungal pathogen–insect host interactions and fungal evolution and systematics. We focus primarily on terrestrial fungi, in particular the Deuteromycota and Entomophthorales, and we include works on entomogenous Oomycetes, which were traditionally classiWed as fungi but are now recognized as phylogenetically distinct (Hawksworth et al., 1995). Fungi as microbial control agents are covered within a separate review by Lord, but here we review aspects of the research done on Metarhizium anisopliae var acridum for locust control. A comprehensive international program facilitated a wide array of studies that serve to illustrate well the marriage of basic and applied research needed to develop a fungal pathogen for use as a microbial control agent. We conclude with our own outlook on where research is headed and what needs to be