A new species, Stibarokris hydrobates sp. nov. is described from Hydrobates pelagicus (Linnaeus) (Procellariiformes: Hydrobatidae) from Malta. This species differs from other representatives of the genus Stibarokris Kethley, 1970 in the absence of the projection on the proximal end of the stylophore (vs. presence in all other species) and in the presence of the basal angles on tarsal claws I–IV (vs. absence). The following syringophilid species are recorded from new hosts of aquatic birds: Stibarokris phoeniconaias (Skoracki and OConnor, 2010) from Phoenicopterus chilensis Molina (Phoenicopteriformes: Phoenicopteridae) from South America, Stibarokris dastychi Glowska and Skoracki, 2011 from Phalacrocorax pygmeus Pallas (Suliformes: Phalacrocoracidae) from Greece, Procellariisyringophilus bulwerius Kethley, 1970 from Calonectris diomedea (Scopoli) (Procellariiformes: Procellariidae) from Spain and Ardenna pacifica (Gmelin) (Procellariidae) from Indonesia.