“Lycostrobus” chinleana,an equisetalean cone from the Upper Triassic of the southwestern United States and its phylogenetic implications

Detailed study of the cone Lycostrobus chinleana Daugherty shows that the fossil was incorrectly attributed to the Lycopodiales by the author and to the quillworts by Retallack and that it actually should be assigned to the Equisetales. The cone, which occurs in the Upper Triassic Chinle Formation at several localities in the southwestern United States, is ∼2.5 cm wide and nearly 6 cm long and consists of a stout axis bearing whorls of peltate sporangiophores. Each sporangiophore is composed of a slender stalk and a hexagonal disk, which typically bears a single, generally long, lanceolate, forward-directed leaf-like umbo tip on the outer surface and several recurrent sporangia on the inner surface. Small round to oval trilete spores occur in the sporangia. Since the leaf-like umbo tip is similar to the sterile leaves found in certain calamite cones and the recurrent sporangia are equisetalean-like, it appears that the cone may represent a intermediate stage between Calamites and modern Equisetum. According to this hypothesis, the nonbracteate Equisetum cone could have developed from a bracteate calamite cone, through reduction and fusion of the bracts and the sporangiophores, rather than by the loss of whorls of bracts of the Calamites cone as suggested earlier by others. As a result of this study the cone is assigned to the new Equisetalean genus Equicalastrobus and redescribed under the name E. chinleana (Daugherty) Grauvogel-Stamm and Ash, n. comb.     

Diet of Buffy Tufted-Eared Marmosets (Callithrix aurita) in a Forest Fragment in Southeastern Brazil

The feeding ecology of the Atlantic forest marmosets (Callithrix spp.) in southeastern Brazil is poorly known, and few studies have focused on buffy tufted-eared marmosets, Callithrix aurita. We determined the food items and investigated the seasonal variation in the diet of a group of four Callithrix aurita in a 17-ha semideciduous forest fragment in southern Minas Gerais State, Brazil. We recorded daily feeding activities between October 1994 and September 1995 using scan sampling at 5-min intervals. The marmosets devoted feeding time to gums (50.5%), fruits (11%), and animal prey (38.5%) in a total of 499 records. Plant resources comprised 27 species from 16 families. They used Acacia paniculata (Mimosoideae, Leguminosae), the main gum source (82%), year-round. Maclura tinctoria (Moraceae) was the fruit species that they consumed most (22%). The marmosets preyed on caterpillars (33%), katydids (5%), and homopterans (4%). Feeding on fruits varied seasonally and was inversely related to gum feeding. Consumption of animal prey remained constant over the year. The wide and year-round dependence on gum suggests that Acacia may play a critical role in marmoset persistence in forest fragments.     

Ecology – a science put to use

There is no lack of pretext for reviewing historically how ecologists have striven to gain the respect of scholars in their own and other fields, and to demonstrate the wider public-utility of their science. If self-serving, in terms of securing the scope and resources required to advance their studies in ecology, such activities have also been encouraged, and indeed commissioned, in the belief that a greater awareness and understanding of the natural world is essential for human wellbeing. Illustrative material is drawn from the British experience.     

Two new species of Diaphanosoma Fischer, 1850(Crustacea: Branchiopoda: Cladocera) from the United States

Two new species of the genus Diaphanosoma, D. oligosetum and D. dorotheae, from Louisiana and North Carolina respectively, are described. The former species has large head with protruding dorsal part, large lanceolate spine on the basipodite's distal outer end, an extremely reduced number of antennal setae, up to six in adult specimens, and unique armament of valve margin. On the whole, it shows the pronounced combination of primitive and specialized morphological traits. D. dorotheae is a member of D. brachyurum species group differing from its other known representatives in presence of a small but very conspicuous spine on the end of proximal segment of antennal exopodite and a variable number of setae (seven or eight) on the distal segment of the branch. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Alarm-recruitment behaviour in Pheidole militicida (Hymenoptera: Formicidae)

ABSTRACT.

• 1 Pheidole militicida Wheeler, a seed-harvesting species of the southwestern United States, possesses a major worker caste (soldiers) with unusually large heads. Previous work suggested that these large major workers are specialized defenders against large seed-harvesting species in the genus Pogonomyrmex.
• 2 Experimental introductions of Pogonomyrmex maricopa Wheeler and the omnivorous fire ant, Solenopsis xyloni McCook, demonstrate that P. militicida colonies alarm-recruit major workers against S.xyloni workers but not against the larger Pogonomyrmex workers.
• 3 P.militicida is the second species in which enemy-specific defence against Solenopsis fire ants has been detected. I suggest that the special role of Solenopsis as both competitor and predator in ant communities frequently favours major worker specialization against this genus.
• 4 Major workers of P.militicida and Pheidole dentata Mayr, the other species with enemy-specific defence against Solenopsis, are morphologically very different from one another. It is suggested that interspecific variation in major worker morphology is not necessarily associated with variation in behavioural specialization.

     

New records for two mosquito predators [Turbellaria: Mesostoma] in the northeastern United States

The accumulated data indicate that mesostomid flatworms are efficient predators of mosquito larvae. This paper presents the 1st published records for 3Mesostoma Ehrenberg, including 2 predators of mosquitoes.Mesostoma californicum Hyman,Mesostoma vernale Hyman, andMesostoma sp. cf.lingua Abildgaard were discovered in a temporary pool in Massachusetts.M. californicum andM. sp. cf.lingua were found to be efficient predators on mosquitoe larvae.

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Résumé Les observations accumulées indiquent que les larves des Plathelminthes mesostomides sont des prédateurs efficaces des larves de moustiques. Cette note présente les premières mentions de 3Mesostoma Ehrenberg incluant 2 prédateurs de moustiques.Mesostoma californicum Hyman,Mesostoma vernale Hyman, etMesostoma sp. cf.lingua Abildgaard furent découverts dans une mare temporaire du Massachusetts.M. californicum etM. sp. cf.lingua ont été reconnus comme des prédateurs efficaces des larves de moustiques.

     

A survey of dermatophytes isolated from human patients in the United States from 1982 to 1984

A survey of dermatophytes isolated from patients seeking medical advice was made from 1982 to 1984 in the United States. The survey included 59 locations with data from 49 cities and one state. Listing of the isolated dermatophytes and the frequency given by percentage of total follows: Trichophyton rubrum 46.8%, T. tonsurans 33.3%, T. mentagrophytes 10.1%, Microsporum canis 4.5%, Epidermophyton floccosum 3,5%, M. gypseum and T. verrucosum both 0.7%, M. audouinii and T. terrestre both 0.1%, and T. violaceum 0.06%. No isolations of M. ferrugineum or T. schoenleinii were reported.Temporal increases were observed for frequencies of T. mentagrophytes, T. tonsurans and M. canis, and decreases occurred for frequencies of E. floccosum and T. rubrum when the data from this survey were compared by the goodness of fit test to data of the 1979 to 1981 survey. The percent of dermatophyte isolations identified as T. tonsurans correlated significantly with the percentage of blacks in cities of 100000 or more people.     

The effects of water abstractions on invertebrate communities in U.K. streams

There are increasing concerns about the ecological effects of water abstraction and in the UK, these concerns have been hightened by the 1976, 1984 and 1988-92 droughts. This paper assesses macroinvertebrate and environmental changes induced by surface and groundwater abstractions on 22 streams throughout the UK.The approach involved comparative research to assess differences between reference and impacted sites.Using a database comprising 204 sets of biological and environmental data (89 taxa and 16 environmental variables) a preliminary ordination using principle components analysis clearly differentiated three types of sites: upland, lowland and an intermediate type. At this scale, any effects of abstractions on invertebrate communities are shown to be insignificant relative to regional controls. A simultaneous ordination of the environmental and faunal differences between pairs of sites was undertaken separately for each of the three regional groups. Differences are considered as vectors having both direction and amplitude and the analysis elucidates common patterns in the faunal and environmental data. Important changes were observed in two situations: upland streams affected by major diversions as part of hydro-power schemes in Scotland and lowland rivers impacted by groundwater abstractions.No strong patterns of change (either in amplitude or orientation) were demonstrated within any of the taxonomic groups. However, within the upland type some rheophilous taxa were shown typically to be reduced in abundance at impacted sites. Within the lowland type, a consistent pattern in the dataset is demonstrated by a group of taxa that are reduced in abundance at the impacted sites.     

A Relational Analysis of American Kinship Terminology

As an alternative to traditional semantic analysis using class-product logic ("Componential analysis"), it is proposed that the possibilities of analysis in terms of relative products be explored in appropriate lexical-taxonomic domains, particularly kinship. In such analyses the order of components is intrinsic to meaning. The process is illustrated by an analysis of American kinship terminology.     

Trends in the perception of ecological problems in the United Nations general debates

To what extent have recent warnings of deepening ecological problems become topics of discussion among international political elites? To address this question a content analysis was undertaken of the speeches comprising the general debates of the 1968, 1972, and 1976 sessions of the UN General Assembly to identify all instances in which ecological issues were mentioned. Despite other indications of an increase in environmental consciousness in the international community, it was found that ecological problems have not been discussed very extensively in the general debates and are far less salient than several other agenda items for which data were also collected. Moreover, the environment peaked as an issue in the 1972 session and declined in prominence in 1976. It was also found that the more developed a country is, the greater the tendency for its delegates to mention environmental problems in their speeches. The lack of prominence of ecological issues is interpreted on the basis of two alternative assumptions: first, that the degree of international awareness of environmental problems is not adequately represented in the general debates and, second, that the findings accurately reflect what is generally a low level of environmental concern in international circles.