38th Annual Meeting of the Society for Invertebrate Pathology

Although microsporidia were first discovered to infect the lady beetle Hippodamia convergens (Guérin-Méneville) in 1959, the effects of microsporidia on this coccinellid have not been studied. In North America, Hippodamia convergens is the primary lady beetle used in biological control. Billions of these coccinellids are collected from overwintering sites in California and sold by commercial insectaries throughout the United States and Canada. The focus of this project was to investigate the effects of microsporidia on fecundity, egg viability, longevity, larval development and sex ratio of commercially available H. convergens. Microsporidia infected and uninfected beetles were reared individually from egg to adult and through to death on an ad libitum diet of green peach aphids (Myzus persicae Sulzer). Larvae were checked daily for signs of moulting and adults were checked daily for egg production. Eggs were kept for one week to observe egg hatch. Upon death, beetles were smeared, stained and examined for the presence of microsporidian spores.