The article by Allison Hansen and her colleagues studies Liberibacter bacteria found in willow-associated psyllids in Europe and North America. The researchers identifies a previously unknown Candidatus Liberibacter haplotype and proposed a new species called Candidatus Liberibacter saliceti. Their genetic analyses suggest that these bacteria may be transferred between different psyllids species. The bacteria may also benefit their insect hosts by providing important nutrients, including amino acids and B vitamins.