Resumo
Urticating setae are exclusive to New World tarantulas and are found in approximately 90% of the New World species. Six morphological types have been proposed and, in several species, two morphological types can be found in the same individual. In the past few years, there has been growing concern to learn more about urticating setae, but many questions still remain unanswered. After studying individuals from several theraphosid species, we endeavored to find more about the segregation of the different types of setae into different abdominal regions, and the possible existence of patterns; the morphological variability of urticating setae types and their limits; whether there is variability in the length of urticating setae across the abdominal area; and whether spiders use different types of urticating setae differently. We found that the two types of urticating setae, which can be found together in most theraphosine species, are segregated into distinct areas on the spider's abdomen: type III occurs on the median and posterior areas with either type I or IV surrounding the patch of type III setae. Morphological intermediates between types I and III, as well as between III and IV, were found. We propose that type III urticating setae have evolved through modifications of body setae on specific areas of abdomen dorsum and subsequently gave independent origin to areas having either type I or IV. A parallel evolution seems to have occurred in some aviculariine genera in which type II setae evolved also from body setae from specific areas of abdomen dorsum. Concerning the length of the setae, we observed that towards the median and posterior areas of the abdomen the length of the urticating setae increases. These long setae are cast by the spider as part of an active defensive behavior against vertebrate predators. We propose that spiders use the various types of urticating setae differently and according to their different targets: type I setae, when incorporated either into the molting web or eggsac, is more effective against invertebrates (ants or phorid fly larvae) than type III. The latter seems to be used mainly against vertebrate predators.
Resumo
Urticating setae are exclusive to New World tarantulas and are found in approximately 90% of the New World species. Six morphological types have been proposed and, in several species, two morphological types can be found in the same individual. In the past few years, there has been growing concern to learn more about urticating setae, but many questions still remain unanswered. After studying individuals from several theraphosid species, we endeavored to find more about the segregation of the different types of setae into different abdominal regions, and the possible existence of patterns; the morphological variability of urticating setae types and their limits; whether there is variability in the length of urticating setae across the abdominal area; and whether spiders use different types of urticating setae differently. We found that the two types of urticating setae, which can be found together in most theraphosine species, are segregated into distinct areas on the spider's abdomen: type III occurs on the median and posterior areas with either type I or IV surrounding the patch of type III setae. Morphological intermediates between types I and III, as well as between III and IV, were found. We propose that type III urticating setae have evolved through modifications of body setae on specific areas of abdomen dorsum and subsequently gave independent origin to areas having either type I or IV. A parallel evolution seems to have occurred in some aviculariine genera in which type II setae evolved also from body setae from specific areas of abdomen dorsum. Concerning the length of the setae, we observed that towards the median and posterior areas of the abdomen the length of the urticating setae increases. These long setae are cast by the spider as part of an active defensive behavior against vertebrate predators. We propose that spiders use the various types of urticating setae differently and according to their different targets: type I setae, when incorporated either into the molting web or eggsac, is more effective against invertebrates (ants or phorid fly larvae) than type III. The latter seems to be used mainly against vertebrate predators.
Resumo
Urticating setae are exclusive to New World tarantulas and are found in approximately 90% of the New World species. Six morphological types have been proposed and, in several species, two morphological types can be found in the same individual. In the past few years, there has been growing concern to learn more about urticating setae, but many questions still remain unanswered. After studying individuals from several theraphosid species, we endeavored to find more about the segregation of the different types of setae into different abdominal regions, and the possible existence of patterns; the morphological variability of urticating setae types and their limits; whether there is variability in the length of urticating setae across the abdominal area; and whether spiders use different types of urticating setae differently. We found that the two types of urticating setae, which can be found together in most theraphosine species, are segregated into distinct areas on the spider's abdomen: type III occurs on the median and posterior areas with either type I or IV surrounding the patch of type III setae. Morphological intermediates between types I and III, as well as between III and IV, were found. We propose that type III urticating setae have evolved through modifications of body setae on specific areas of abdomen dorsum and subsequently gave independent origin to areas having either type I or IV. A parallel evolution seems to have occurred in some aviculariine genera in which type II setae evolved also from body setae from specific areas of abdomen dorsum. Concerning the length of the setae, we observed that towards the median and posterior areas of the abdomen the length of the urticating setae increases. These long setae are cast by the spider as part of an active defensive behavior against vertebrate predators. We propose that spiders use the various types of urticating setae differently and according to their different targets: type I setae, when incorporated either into the molting web or eggsac, is more effective against invertebrates (ants or phorid fly larvae) than type III. The latter seems to be used mainly against vertebrate predators.
Resumo
The male holotype of Hapalopus nondescriptus Mello-Leitão, 1926 is redescribed, illustrated and compared with freshly collected specimens from the type locality. The only difference noted among the holotype and the new material concerns the development of the subapical keel. Its taxonomic position is reinterpreted and discussed, resulting in its transfer to the genus Vitalius Lucas, Silva Junior & Bertani, 1993, and thus making the new combination Vitalius nondescriptus (Mello-Leitão, 1926) comb. nov. The female is described for the first time and the morphological variations in two males, born from the female used in the description, is presented and illustrated. The male differs from those of other Vitalius species by the palpal bulb with short apical keel and bifid tibial spur with narrow prolateral branch and almost straight retrolateral branch. The female differs from those of other Vitalius species by urticating hair of 'type I' having the region 'a' shorter than region 'b'. Hapalopus nondescriptus has a confusing taxonomic history, since the holotype specimen was also used to describe another theraphosid species (Cyclosternum melloleitaoi Bücherl, Thimoteo & Lucas, 1971) which was, consequently, considered its objective synonym. Thus, we consider it a clear example of theraphosid taxonomical chaos.
Resumo
The male holotype of Hapalopus nondescriptus Mello-Leitão, 1926 is redescribed, illustrated and compared with freshly collected specimens from the type locality. The only difference noted among the holotype and the new material concerns the development of the subapical keel. Its taxonomic position is reinterpreted and discussed, resulting in its transfer to the genus Vitalius Lucas, Silva Junior & Bertani, 1993, and thus making the new combination Vitalius nondescriptus (Mello-Leitão, 1926) comb. nov. The female is described for the first time and the morphological variations in two males, born from the female used in the description, is presented and illustrated. The male differs from those of other Vitalius species by the palpal bulb with short apical keel and bifid tibial spur with narrow prolateral branch and almost straight retrolateral branch. The female differs from those of other Vitalius species by urticating hair of 'type I' having the region 'a' shorter than region 'b'. Hapalopus nondescriptus has a confusing taxonomic history, since the holotype specimen was also used to describe another theraphosid species (Cyclosternum melloleitaoi Bücherl, Thimoteo & Lucas, 1971) which was, consequently, considered its objective synonym. Thus, we consider it a clear example of theraphosid taxonomical chaos.
Resumo
The male holotype of Hapalopus nondescriptus Mello-Leitão, 1926 is redescribed, illustrated and compared with freshly collected specimens from the type locality. The only difference noted among the holotype and the new material concerns the development of the subapical keel. Its taxonomic position is reinterpreted and discussed, resulting in its transfer to the genus Vitalius Lucas, Silva Junior & Bertani, 1993, and thus making the new combination Vitalius nondescriptus (Mello-Leitão, 1926) comb. nov. The female is described for the first time and the morphological variations in two males, born from the female used in the description, is presented and illustrated. The male differs from those of other Vitalius species by the palpal bulb with short apical keel and bifid tibial spur with narrow prolateral branch and almost straight retrolateral branch. The female differs from those of other Vitalius species by urticating hair of 'type I' having the region 'a' shorter than region 'b'. Hapalopus nondescriptus has a confusing taxonomic history, since the holotype specimen was also used to describe another theraphosid species (Cyclosternum melloleitaoi Bücherl, Thimoteo & Lucas, 1971) which was, consequently, considered its objective synonym. Thus, we consider it a clear example of theraphosid taxonomical chaos.
Resumo
The aim of this work was to study biological aspects and the life cycle of Hylesia Metapyrrha in a laboratory. Laboratorial breeding was made at 25 ± 1 °C, 70 ± 10% UR and 14 hours of photophase, feeding the larvae with guava leaves (Psidium guayava L. - Myrtaceae). Time was evaluated on the days of all the development stages; morphometry was evaluated in millimeters and the pupas mass in grams. The eggs were disposed in groups and covered by urticating abdominal hair. The incubation period lasted 52 days. The larvae, with gregarious habits, presented background black coloration, yellowish scoli and two orange longitudinal lines above and below the spiracles, during the development which lasted an average period of 74.59 days and went through seven instars. The pre-pupa and the pupa stages lasted on average 8.82 and 50.56 days, respectively; the female pupae presented a duration, weight and size which was significantly bigger. The adult stage lasted on average 5.50 days with periods of pre, post and oviposition of 2.30, 1.90 and 1.00 days, respectively. This study broadens the knowledge of the immature stages, biological, morphological and behavioral aspects, until then restricted to the morphology and to registers of the occurrence of the adult forms.
O presente estudo objetivou estudar aspectos biológicos e o ciclo de vida de Hylesia metapyrrha em laboratório. Para tanto, foi realizada uma criação laboratorial a 25 ± 1 °C, 70 ± 20% UR e 14 horas de fotofase, alimentando-se as lagartas com folhas de goiabeira (Psidium guajava L - Myrtaceae). Para todas as fases de desenvolvimento, foram avaliados o tempo em dias, a morfometria em milímetros e, para as pupas, a massa, em gramas. Também foram feitas observações sobre características morfológicas e etológicas. Os ovos, de formato subcilíndrico, são dispostos em grupos e recobertos por cerdas abdominais urticantes, o período de incubação foi de 52,00 dias. As lagartas, de hábito gregário, apresentam coloração de fundo negra, escolos amarelados e duas linhas longitudinais laranja dispostas acima e abaixo dos espiráculos, durante o desenvolvimento que teve um período médio de 74,59 dias, passaram por sete ínstares. As fases de pré-pupa e pupa duraram em média 8,82 e 50,56 dias, respectivamente, sendo que as pupas do sexo feminino apresentaram duração, peso e tamanho significativamente maiores que as dos machos. A fase adulta durou em média 5,50 dias, com períodos de pré, pós e oviposição de 2,30, 1,90 e 1,00 dias, respectivamente. Este estudo amplia os conhecimentos sobre as fases imaturas, aspectos biológicos, morfológicos e comportamentais até então restritos apenas à morfologia e registros da ocorrência das formas adultas.