AbstractPhlebotomine larval taxonomy is briefly reviewed with particular reference to New World species, of which under one fifth have been adequately described as immature stages. A new numerical chaetotaxy is proposed following studies on the larvae of six species from Brazil. Setal numeration is used in a manner which demonstrates apparent segmental homologies and the use of letter designations for some setae has been reduced. With two exceptions the mesothoracic, metathoracic and abdominal setae are homologized with those of the posterior prothorax, and the anterior prothoracic setae are regarded as atypical.