Fungal endophytes are important symbionts of many grasses. The fungi produce alkaloids that appear to protect their hosts from herbivores. The fungi can also produce fruiting structures that Botanophila flies visit for egg laying. The study of this interaction has taken me to New Zealand, England, and Switzerland, as well as parts of the US. I describe work over the last 20 years in which I have asked basic ecological questions about the interaction between grasses, fungi and insects.