Alyssum is a perennial from the Mediterranean with an unusual
ability to flower uninterrupted for extended periods (Pico and Retana,
2003), and in California it is a common ornamental that has naturalized
in some coastal regions (DiTomaso and Healy, 2007).
Alyssum is one of the most frequently studied species in habitat
management for conservation biological control (Fiedler et al.,
2008). Chaney (1998) identified alyssum as a promising insectary
plant to intercrop with lettuce because alyssum flowered quickly
after planting, was not overly aggressive or likely to become a weed,
and attracted several beneficial species but few pest species. For
more than 10 years, alyssum has been planted as an insectary plant
in organic lettuce fields in California to attract adult hoverflies (Diptera:
Syrphidae) that feed on pollen and nectar (Bugg et al., 2008).