Immature argasid ticks: diagnosis and keys for neotropical region / Carrapatos argasídeos imaturos: diagnoses e chaves para a região neotropical

Many argasid tick species are known only through their larval descriptions, in which the chaetotaxy, together with other external morphological characteristics, has been used to separate genera and species. However, the illustrations of these features are based on optical microscopy alone and many of these features are not clearly defined. Because of the difficulties in determining the larval and nymph stages of some genera, we have prepared illustrated keys for the immature stages of argasids, including an up-to-date list of the known species of the Neotropical region. We have also included an illustrated key for larvae of the Ornithodoros species from Brazil, based on scanning electron microscopy.

Muitos carrapatos argasídeos são conhecidos somente por descrições larvais, nas quais a quetotaxia associada a outros caracteres morfológicos tem sido usada para separar gêneros e espécies. No entanto, as ilustrações sobre esses caracteres são baseadas somente em microscopia óptica e muitos deles não estão claramente definidos. Devido às dificuldades em determinar estágios larvais e ninfais de alguns gêneros, elaboramos chaves ilustradas para os estágios imaturos de argasídeos, incluindo uma lista atualizada de espécies conhecidas da região Neotropical. Incluímos também uma chave ilustrada para larvas das espécies de Ornithodoros do Brasil baseada em microscopia eletrônica de varredura.

Ixodes (Haemixodes) longiscutatum Boero (new status) and I. (H.) uruguayensis Kohls & Clifford, a new synonym of I. (H.) longiscutatum (Acari: Ixodidae)

Females of Ixodes (Haemixodes) uruguayensis Kohls & Clifford, 1967, a species whose adults were unknown until the present, were obtained in the laboratory from engorged nymphs collected on rodents (Scapteromys tumidus and Oxymycterus nasutus) in the counties of Maldonado and San José, Uruguay. Morphological characters of these females were identical to those given in the description of the female of Ixodes longiscutatum Boero, 1944. I. uruguayensis is, thus, relegated to a junior subjective synonym of I. longiscutatum. However, because of the unique morphological characters of the immature stages, the validity of the subgenus Haemixodes Kohls & Clifford, 1967 is not questioned. Therefore, the new status of Ixodes (Haemixodes) uruguayensis Kohls & Clifford, 1967 is Ixodes (Haemixodes) longiscutatum Boero, 1944