Mildew infection of wild lupine may be increased in denser wild lupine patches. In addition, larval length was positively associated with wild lupine height in central Wisconsin. First flight females lay the vast majority of their eggs on wild lupine. Significant flora includes mayapple, bluets, wild lupine, cardinal flower, and pinxter flower. However, available evidence suggests that senescent wild lupine is a poor larval food source. Size of habitat patches can also influence Karner blue butterfly abundance (see section "Wild lupine"). Wild lupine are typically more abundant in open areas than in shade. Wild lupine is the sole larval food source of the Karner blue butterfly. Shade-grown wild lupine has been shown to provide higher quality larval resource than sun-grown lupine.