Oviposition preferences of two predatory hoverflies, Episyrphus balteatus and Syrphus
ribesii (Diptera, Syrphidae), were studied in the laboratory. 2. There was broad agreement
between the two species: two of the top three preferred prey for oviposition in both hoverflies
were pea and rose aphids; nettle aphids were consistently the least preferred. 3.
Discrimination decreased with age.