999 resultados para Larval description


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Mithrax hispidus (Herbst, 1790) is a mithracid majoid crab occurring on sand, corals and rocks in waters of the western Atlantic. Larval development consists of two zoeal stages and a megalopa. All larval stages are described in detail based on multiple cultures. Prior to this study, larvae of M hispidus were considered to be different and grouped separately from most other larvae of Mithrax, primarily based on setation. A detailed morphological examination, based on the same specimens used for the first description, revealed that the inclusion of M hispidus in a separate group is not valid as zoeae now fully agree with the morphological characteristics defined for the other group of five Mithrax species, including M. pleuracanthus, M. verrucosus, M. caribbaeus, M. coryphe, and M. forceps. This illustrates the importance of precisely recording morphological details such as setation, which may otherwise lead to incorrect interpretations with regard to perceived taxonomic affinities. A comparison of larvae of the Mithrax -Mithraculus species complex does not support separation into two genera. Larval evidence supports the recently suggested adult-based synonymization of M caribbaeus with M. hispidus.

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(Gyllenhal) is a common firefly in the Southeastern region of Brazil. Adults and larvae were collected in the municipality of Campinas, state of So Paulo, Brazil, and the immature stages were described and reared in the laboratory. Four generations were reproduced in the laboratory, and a method for its rearing was established. The life cycle usually lasts 6 months, but under optimal laboratory conditions, it lasted from 2 to 4 months. Larvae were fed with and snails since the beginning of the larval stage. This species was found to be easily adapted to environments under anthropic influence, such as urban areas and farms.

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Immatures of the Phelypera schuppeli (Boheman, 1834) (Curculionidae; Hyperinae; Cepurini) are described, illustrated and compared with available descriptions of larvae and pupae of Hyperini. Immatures and adults from midwest (Dourados, Mato Grosso do Sul; Pirenopolis, Goias) and southeast Brazil (Bauru, Sao Paulo) were found on leaves of the host plant, Pachira aquatica Aubl. (Malvaceae, formerly Bombacaceae), a tree used as an ornamental plant in many Brazilian frost-free cities. Larvae of P. schuppeli are exophytic, brightly colored, eruciform and possess abdominal ambulatory ampullae, resembling larvae of Lepidoptera. Mature larvae can spin globular lattice-like cocoons where pupation takes place. Data in the field and under laboratory conditions confirmed previously published biological observations on P. schuppeli. Additional information about defensive behaviors, process of cocoon construction and natural enemies, such as the larval predator Supputius cinticeps (Stal, 1860) (Hemiptera: Pentatomidae) and the prepupal and pupal parasitoid Jaliscoa nudipennis Boucek, 1993 (Hymenoptera: Pteromalidae), are reported.

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ALBERTONI F F [Fed Univ, Florianopolis, Brazil], MORAES S S [Mus Zool USP, Sao Paulo, Brazil], STEINER J [Fed Univ. Florianopolis, Brazil] & ZILLIKENS A [Univ Tubingen, Germany]: Description of the Pupa and Redescription of the Imagines of Geyeria decussata and their Association with Bromeliads in Southern Brazil (Lepidoptera: Castniidae). - Entomol Gener 34 (1-2): 061-074: Stuttgart 2012-09. - [Article] Bromeliads can serve as a resource for numerous arthropods, especially insects. Caterpillars of the moth Geyeria decussata (Godart 1824) were recorded in the leaf rosettes of the bromeliads Wittrockia superba, Vriesea philippocoburgii and Aechmea nudicaulis. The larvae were feeding on the leaf bases, eventually killing the plants. In addition to life history data a description of the pupa and a re-description of the imagines are provided here. These findings constitute new records of larval hosts for this species and confirm a close association of castniid moths and bromeliads.

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[EN] First description of the complete embryo and larval development of the Canarian abalone (Haliotis tuberculata coccinea Reeve.) was conducted along 39 stages from fertilization to the appearance of the third tubule on the cephalic tentacles and illustrated in a microphotographic sequence. Eggs obtained by induced spawning with hydrogen peroxide from the GIA captive broodstock were stocked at a density of 10 eggs/mL and kept at 23 0.5 BC for 62 h until the formation of the third tubule. Live eggs and larvae were continuously observed on a 24 h basis at a 3400 magnification under transmitted light. At each stages, specific morphological features, illustrated by microscopic photographs, were described, as well as the time required for their apparition. Fertilized eggs diameter was 205 8 mm (mean SD), whereas length and width of larvae ready to undergo metamorphosis were 216.6 5.3 mmand 172 8.8 mm, respectively. Knowledge on the larval morphological development acquired through this study will contribute to the improvement of larval rearing techniques for this abalone species.

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Existen pocas publicaciones sobre claves de identificación de larvas de trips. Sin embargo, el tema es de interés básico para detectar el rango de hospedantes de los trips. Algunas especies son capaces de transmitir Tospovirus, agentes causales de la peste negra y otras enfermedades. El insecto adquiere el virus sólo como larva. Una clave de larvas será una herramienta útil para estudios epidemiológicos. La identificación de larvas es difícil porque tienen menos caracteres distintivos que los adultos; además, los individuos crecen constantemente. Las larvas obtenidas para este trabajo se recolectaron del campo sobre varias malezas y algunas plantas nativas y cultivadas. También se criaron en chauchas de poroto o polen y miel diluida a partir de adultos identificados. En este trabajo se presenta una descripción breve del segundo estadío larval de Frankliniella australis Morgan, F. gemina Bagnall, F. occidentalis Pergande, F. schultzei Trybom, F. valdiviana Sakimura et O'Neil y Thrips tabaci Lindeman y una clave para separar estas especies. Estación Experimental Agropecuaria INTA Mendoza.

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The development of gymnolaemate Ectoprocta includes a larval stage of either the coronate or the cyphonautes type. Herein, we provide the first description of the larval neural anatomy of a coronate larva using immunocytochemical methods. We used antibodies against the neurotransmitters serotonin and FMRFamide and followed the fate of immunoreactive cells through metamorphosis. The larval serotonergic nervous system of Triphyllozoon mucronatum consists of an apical commissure, one pair of lateral axons, a coronate nerve net, an internal nerve mesh, and one pair of axons innervating the frontal organ. FMRFamide is only found in the larval commissure and in the lateral axons. The entire serotonergic and FMRFamidergic nervous system is lost during metamorphosis and the adult neural structures form independent of the larval ones. In the postlarval zooid, both neurotransmitters are detected in the cerebral commissure, in cell bodies located at the base of the lophophore, and in neurites connecting these somata to the cerebral commissure. These findings differ significantly from that observed in other lophotrochozoans, where certain larval neural features are either incorporated in the adult nervous system and/or have inductive functions during its ontogeny. The occurrence of a larval commissure and the lack of a serotonergic or FMRFamidergic apical organ in T. mucronatum are unique among lophotrochozoan larvae, which usually have a distinct apical organ containing serotonergic cells. Our data show that the larval neuroanatomy and the processes that underlie the reorganization of larval organ systems during metamorphosis may vary much more among lophotrochozoan taxa than previously thought.

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Little is known of the blood parasites of coral reef fishes and nothing of how they are transmitted. We examined 497 fishes from 22 families, 47 genera, and 78 species captured at Lizard Island, Australia, between May 1997 and April 2003 for hematozoa and ectoparasites. We also investigated whether gnathiid isopods might serve as potential vectors of fish hemogregarines. Fifty-eight of 124 fishes caught in March 2002 had larval gnathiid isopods, up to 80 per host fish, and these were identified experimentally to be of 2 types, Gnathia sp. A and Gnathia sp. B. Caligid copepods were also recorded but no leeches. Hematozoa, found in 68 teleosts, were broadly hemogregarines of 4 types and an infection resembling Haemohormidium. Mixed infections (hemogregarine with Haemohormidium) were also observed, but no trypanosomes were detected in blood films. The hemogregarines were identified as Haemogregarina balistapi n. sp., Haemogregarina tetraodontis, possibly Haemogregarina bigemina, and an intraleukocytic hemogregarine of uncertain status. Laboratory-reared Gnathia sp. A larvae, fed experimentally on bruslitail tangs, the latter heavily infected with the H. bigemina-like hemogregarine, contained hemogregarine gamonts and possibly young oocysts up to 3 days postfeeding, but no firm evidence that gnathiids transmit hemogregarines at Lizard Island was obtained.

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Available information on the larval release rhythms of brachyurans is biased to temperate estuarine species and outcomes resulting from some sort of artificial manipulation of ovigerous females. In this study we applied field methods to describe the larval release rhythms of an assemblage of tropical rocky shore crabs. Sampling the broods of ovigerous females of Pachygrapsus transversus at two different shores indicated a spatially consistent semilunar pattern, with larval release maxima around the full and new moon. Yet, synchronism between populations varied considerably, with the pattern obtained at the site exposed to a lower wave action far more apparent. Breeding cohorts at one of the sampled shores apparently belonged to actual age groups composing the ovigerous population. The data suggest that these breeding groups release their larvae in alternate syzygy periods, responding to a lunar cycle instead of the semilunar pattern observed for the whole population. For the description of shorter-term rhythms, temporal series at hour intervals were obtained by sampling the plankton and confinement boxes where ovigerous females were held. Unexpectedly, diurnal release activity prevailed over nocturnal hatching. Yet, only grapsids living higher on the shore exhibited strong preferences over the diel cycle, with P. transversus releasing their larvae during the day and Geograpsus lividus during the night. The pea crab Dissodactylus crinitichelis, the spider crab Epialtus brasiliensis and a suite of xanthoids undertook considerable releasing activity in both periods. Apart from the commensal pea crab D. crinitichelis, all other taxa revealed tide-related rhythms of larval release, with average estimates of the time of maximum hatching always around the time of high tides; usually during the flooding and slack, rather than the ebbing tide. Data obtained for P. transversus females held in confinement boxes indicated that early larval release is mostly due to nocturnal hatching, while zoeal release in diurnal groups took place at the time of high tide. Since nocturnal high tides at the study area occurred late, sometimes close to dusk, early release would allow more time for offshore transport of larvae when the action of potential predators is reduced.

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Linepithema micans Forel is a poorly studied species that is now considered a pest in vineyards in South Brazil. Larval characters have been used in a few phylogenetic studies, and their importance greatly depends in the amount of available information on different species. This study presents a complete panorama on the external morphology of the immatures of L. micans based on observations by light and scanning electron microscopy. The number of larval instars was estimated as three based on the frequency distribution of head widths of 965 larvae. Larvae of L. micans were similar to other Linepithema Mayr in the general format of body and mandibles, presenting a dorsal abdominal protuberance, nine pairs of spiracle, and unbranched hairs. On the other hand, L. micans was unique for having shorter hairs, predominantly denticulate, intraspecific variation in the number of antennal sensilla and in the types of sensilla on the labial palps were reported.

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Through media such as newspapers, letterbox flyers, corporate brochures and television we are regularly confronted with descriptions for conventional (bricks 'n' mortar style) services. These representations vary in the terminology utilised, the depth of the description, the aspects of the service that are characterised and their applicability to candidate service requestors. Existing service catalogues (such as the Yellow Pages) provide little relief for service requestors from the burdensome task of discovering, comparing and substituting services. Add to this environment the rapidly evolving area of web services with its associated surfeit of standards, and the result is a considerably fragmented approach to the description of services. It leaves the reality of the Semantic Web somewhat clouded. --------- Let's consider service description briefly, before discussing our concerns with existing approaches to description. The act of describing is performed prior to advertising. This simple fact provides an interesting paradox as services cannot be described exactly before advertisement. This doesn't mean they can't be described comprehensively. By "exactly", we are referring to the fact that context provided by a service requestor (and their service needs) will alter the description of the service that is presented to the discoverer. For example, a service provider who operates a cinema wants to describe the price of their service. Let's say the advertised price is $15. They also want to state that a pensioner discount and a student discount is available which provides a 50% discount. A customer (i.e. service requestor) uses the cinema web site to purchase tickets online. They find the movie of their choice at a time that suits. However, its not until some context is provided by the requestor that the exact price is determined. The requestor might state that they are a pensioner. The same is applicable for a service requestor who purchases multiple tickets perhaps on behalf of other people. The disconnect between when the service is described and when a requestor provides context introduces challenges to the description process. A service provider would be ill-advised to offer independent descriptions that represent all the permutations possible for a single service. The descriptive effort would be prohibitive.

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This study assessed the reliability and validity of a palm-top-based electronic appetite rating system (EARS) in relation to the traditional paper and pen method. Twenty healthy subjects [10 male (M) and 10 female (F)] — mean age M=31 years (S.D.=8), F=27 years (S.D.=5); mean BMI M=24 (S.D.=2), F=21 (S.D.=5) — participated in a 4-day protocol. Measurements were made on days 1 and 4. Subjects were given paper and an EARS to log hourly subjective motivation to eat during waking hours. Food intake and meal times were fixed. Subjects were given a maintenance diet (comprising 40% fat, 47% carbohydrate and 13% protein by energy) calculated at 1.6×Resting Metabolic Rate (RMR), as three isoenergetic meals. Bland and Altman's test for bias between two measurement techniques found significant differences between EARS and paper and pen for two of eight responses (hunger and fullness). Regression analysis confirmed that there were no day, sex or order effects between ratings obtained using either technique. For 15 subjects, there was no significant difference between results, with a linear relationship between the two methods that explained most of the variance (r2 ranged from 62.6 to 98.6). The slope for all subjects was less than 1, which was partly explained by a tendency for bias at the extreme end of results on the EARS technique. These data suggest that the EARS is a useful and reliable technique for real-time data collection in appetite research but that it should not be used interchangeably with paper and pen techniques.