Spittlebug indicators of nitrogen‐fixing plants

Spittlebugs (Homoptera: Cercopoidea) are preferentially associated with nitrogen‐fixing angiosperms. Generally, the Aphrophoridae associate with legumes, the Clastopteridae with actinorhizal plants, and the Cercopidae with associative nitrogen‐fixing grasses. This is the first reported insect—host association specific to nitrogen‐fixing plants. It is probable that spittlebugs are attracted to nitrogen‐fixing plants because these hosts provide a relatively rich, reliable source of organic nitrogen compounds for xylem‐sucking insects. Many spittlebugs live on plants that do not fix nitrogen, and ecological, mechanical or chemical factors may bar some spittlebugs from otherwise suitable nitrogen‐fixing plants. Among nitrogen‐fixing hosts, spittlebugs appear to prefer plants that transport fixed nitrogen as amino acids and amides to plants that transport fixed nitrogen as ureides.