摘要:

Spiny pocket mice (Liomys pictus) were maintained on monospecific diets of fruits and seeds of twelve plant species from a tropical deciduous forest in Mexico. Average consumption rates over 5-day trials were determined and classified as high, moderate or low. The products of plant species providing the most valuable food to spiny pocket mice were shown to contain high crude protein or lipid contents. The least valuable dietary components contained glucosides and alkaloids possibly deterrent to spiny mice, however, some of these fruits or seeds were moderately consumed. It is concluded that nutritional value or presence of toxic compounds in fruits and seeds might affect dietary choices of spiny pocket mice. Individuos del ratón espinoso de abazones Liomys pictus fueron alimentados con dietas monoespec¡ficas de frutos y semillas de 12 especies de plantas de una selva tropical decidua en México. El consumo promedio durante cinco días del experimento fue mayor (> 0.25 g semilla/g ratón) para las semillas de Pithecellobium dulces, Delonyx regia, Albizia occidentalis y Enterolobium cyclocarpum (Leguminosae) y de girasol Helianthus annuus (Compositae), moderado (0.10–0.20 g semilla/g ratón) para los frutos de Guazuma ulmifolia (Sterculaceae) y Coccoloba barbadensis (Polygonaceae) y las semillas de Crescentia alata (Bignoniaceae) y Recchia mexicana (Simaroubaceae) y, menor (< 0.10 g semilla/g ratón) para las semillas de Caesalpinia pulcherrima (Leguminosae) y frutos de Celtis iguanaeus (Ulmaceae) y Amphypterygium adstringens (Julianaceae). Los valores dietéticos (promedio de la variación de la masa corporal/promedio de consumo de frutos y semillas) indicaron que H. annuus, E. cyclocarpum, A. occidentalis y D. regia fueron las especies con mejores rendimientos y mostraron contenidos altos en proteína ó lípidos crudos. Por su parte, C. iguanaeus, A. adstringens y C. pulcherrima fueron las especies con rendimientos más bajos y mostraron contenidos de glucósidos y/o alcaloides, posiblemente tóxicos para L. pictus. Sin embargo, algunos frutos y semillas fueron consumidos a£n mostrando contenidos de alcaloides. El contenido nutricional y la presencia de compuestos tóxicos pueden determinar la selección de frutos y semillas del ratón espinoso de abazones en condici ones naturales.

ISSN:0165-0521    

DOI:10.1076/snfe.34.2.65.2101

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The predatory behavior of Didelphis albiventris (Didelphidae) on Bothrops jararaca (Viperidae) was described from encounters provoked in captivity. One adult and four young opossums presented the same behavior when killing and ingesting the snakes. Opossums subjugated the snakes by biting them in the head or neck region and began ingestion by eating this part first. The total time spent in subjugation plus ingestion was 24:23 min (SD = 8:08 min). Although D. albiventris is resistant to snake venom, the behavioral sequence observed is, probably, not a specialization for snake predation. It probably consists of a general and primitive pattern of prey manipulation observed in carnivorous mammals.

ISSN:0165-0521    

DOI:10.1076/snfe.34.2.72.2105

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In the Atlantic rain forest (Mata Atlântica) of Northeastern Brazil the seasonality of termite swarming was studied by light trap captures. Swarming started in November and ended in July, with a high incidence at the beginning of the rain season, March through May. Alates of twenty four morpho-species of the families Kalotermitidae, Rhinotermitidae and Termitidae were sampled. The latter were the most abundant group. Sex ratio was approximately 1:1. The influence of external factors on the monthly capture rates was analysed by multiple regression, resulting in air temperature and rain fall as the main determinants. The periods of swarming now known for termite populations in different regions of Brazil are discussed under aspects of climate and habitat characters. Revoadas de cupins foram estudadas com coletas cont¡nuas em armadilhas luminosas em dois sítios de Mata Atlântica no Nordeste do Brasil (João Pessoa, Estado da Paraíba) de agosto de 1994 a julho de 1995. Alados foram capturados em 90 de 196 intervalos de coleta (2 armadilhas; intervalos de 3 a 4 dias). As revoadas começaram em novembro de 1994 e terminaram em julho de 1995 com uma maior incidência no início da estação chuvosa (março-maio). A diversidade de alados nas capturas foi maior no pico da estação chuvosa. Um total de 11.367 indivíduos foram coletados; identificamos 24 morfo-espécies, sendo seis morfo-espécies de Kalotermitidae, três morfo-espécies de Rhinotermitidae e quinze morfo-espécies de Termitidae (apenas três gêneros puderam ser identificados). O índice Sfrensen de similaridade entre as duasÝáreas foi de 80%, mostrando que a composição de espécies nas duas Ýreas foi bastante similar. Os alados de Termitidae foram os mais abundantes (abundância relativa de 78 e 84%, respectivamente, para área A e B). Kalotermitidae foi a família mais freqüente, e Rhinotermitidae a menos freqüente e menos abundante. Entre as espécies identificadas, as mais abundantes e/ou freqüentes foram os dos gêneros Neotermes (Kalotermitidae), Heterotermes and Coptotermes (ambos Rhinotermitidae) que voaram a partir do final da época seca. A proporção entre machos e fêmeas na amostra total foi de aproximadamente 1:1. A precipitação explicou 37% e a temperatura 42% da variação do número mensal de alados numa análise de regressão múltipla.

ISSN:0165-0521    

DOI:10.1076/snfe.34.2.76.2103

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Three new genera and three new species of Baetidae (Insecta: Ephemeroptera) are described from the Andes and Patagonia. Larvae of Andesiops, new genus, are distinguished by the apically bifid right prostheca and two rows of denticles on the tarsal claws. Larvae of Deceptiviosa, new genus, are distinguished by the apically bifid right prostheca and small subapical denticle on the tarsal claws. Larvae of Nanomis, new genus, are distinguished by the apically acute maxillary palp segment 2, smooth posterior margin of the terga, and paddle-shaped subapical seta on the hindtibiae. Adults of Andesiops and Deceptiviosa are similar, but distinguished from other South American baetids by having hindwings with a small costal process in the basal one third and three lon gitudinal veins with the middle vein being forked, and an elongate and ellipsoidal genital forceps segment 3. Larvae and adults of Andesiops peruvianus, new combination, are redescribed, and additional locale data are provided for Argentina, Bolivia, Ecuador, and Venezuela. Deceptiviosa ardua, new species, is described from larvae from Chile, and D. torrens, new species, is described from larvae and adults from Chile and Argentina. Nanomis galera, new species, is described from larvae from Argentina, Colombia, Ecuador, and Peru.

ISSN:0165-0521    

DOI:10.1076/snfe.34.2.88.2102

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Four new species of spitting spiders of the genus Scytodes are described: S. panguana from Peruvian Amazonia and S. paarmanni, S. martiusi and S. janauari from central Amazonia in Brazil. All are small, short legged scytodids. The specimens were collected in the course of ecological studies in the leaf litter layer on the ground of Amazonian terra firme forests. Quatro novas espécies de Scytode s são descritas: S. panguana da Amazônia peruana e S. paarmanni, S. martiusi e S. janauari da Amazônia central do Brasil. Todas são espécies pequenas, de pernas curtas, que foram coletadas durante estudos ecológicos em liteira no chão de florestas de terra firme da Amazônia.

ISSN:0165-0521    

DOI:10.1076/snfe.34.2.105.2104

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Notodiaptomus Kiefer, 1936 is the most abundant and speciose genus of freshwater calanoids in the Neotropical region. The type species, N. deitersi (Poppe, 1891) is in need of redescription but the type material is no longer extant and the type locality no longer exists. In order to avoid possible confusion over the identity of the type species of the genus, a neotype is designated. This is an adult ? from Baia Pedra Branca because this locality is near CuiabÝ, in the State of Mato Grosso, Brazil, the original type locality. The neotype is described and this description forms the basis for a complete diagnosis of the genus Notodiaptomus. Like most diaptomid genera Notodiaptomus is characterized by prosome morphology, by the fifth legs in both sexes and by the? geniculate antennule. Sexual dimorphism in the rostrum is reported here and the homology of the modified setal elements on the geniculate right antennule of the ? is analysed.

ISSN:0165-0521    

DOI:10.1076/snfe.34.2.114.2106

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor