Egg development of Plecoptera,Ephemeroptera and Odonata along latitudinal gradients

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A new species of endophytic Balansia from Veracruz, Mexico

A new graminicolous species of Clavicipitaceae, Balansia brunnans sp. nov., has been found to infect Panicum xalapénse. Staining of living host tissues indicates the presence of intercellular endophytic mycelium. Stromata develop just below the nodes on the culms. Balansia brunnans is comparable to Balansia aristidae, B. discoidea, B. gaduae, B. nigricans, and B. strangulans in development of stromata on culms and possession of an endophytic mycelial stage. Among the differences between Balansia brunnans and other comparable species is that it possesses a brown perithecial stroma, whereas comparable species have black perithecial stromata. A key is provided to distinguish B. brunnans from similar species.     

Life Cycles and Emergence of Ephemeroptera and Plecoptera from Myrkdalsvatn,an Oligotrophic Lake in Western Norway

Comparative data are presented on nymphal growth and adult emergence for Nemoura avicularis, N. cinerea (Plecoptera), Siphlonurus aestivalis, S. lacustris and Leptophlebia vespertina (Ephemeroptera) from lake Myrkdalsvatn, western Norway. These species are all univoltine in Myrkdalsvatn. However, they show different nymphal growth patterns and emergence periods. The timing of emergence in Plecoptera was largely determined by water temperature, and in the Ephemeroptera by changes in both water temperature and cloud cover.     

An early classic sculpture from El Tajin,Veracruz, Mexico

Us and Them in Modern Societies: Ethnicity and Nationalism in Trinidad, Mauritius and Beyond. 1992. Thomas Hylland Eriksen. Oxford: Oxford University Press, and Oslo: Scandinavian University Press, xii + 208 pp.     

New mayfly nymphs (Insecta: Ephemeroptera) from Yixian Formation,China

Three new species of mayfly nymphs, Clavineta excavata sp. nov., Clavineta brevinodia sp. nov., and Siberiogenites branchicillus sp. nov., from the Yixian Formation (Late Jurassic-Early Cretaceous) in western Liaoning Province, China, are described. These mature nymphs are small-sized, with the body less than 16.0 mm long. The systematic position of the genera Clavineta and Siberiogenites, which are recorded for the first time in the Yixian Formation, is briefly discussed.     

Distributions of Ephemeroptera, Plecoptera, and Trichoptera of three maritime catchments differing in pH

1. Two broad-scale environmental influences affecting species of Ephemeroptera, Trichoptera and Plecoptera inhabiting riffle habitat of three study catchments in New Brunswick and Nova Scotia were stream size-temperature-related variables and acidity-related variables. 2. Species richness was most affected by acidity in tributaries of intermediate size <0.001<0.1m³s^?1). 3. Of the three insect orders investigated, mayfly species richness was affected most by acidity, and stonefly species richness affected least by this factor. 4. Zoogeographical isolation of the Nova Scotian catchments resulted in absence of some species of low general abundance, but these species had little influence on the site classification by TWINSPAN analysis. 5. Predaceous stoneflies were collected in greater numbers from circumneutral sites and predaceous caddisflies in greater numbers from the Nova Scotian sites. 6. Although the Nova Scotian catchments have probably been historically acidic, due to high concentrations of organic acids, pH currently limits the distributions of many indigenous invertebrate species. These species may be vulnerable to the more recent, additional, anthropogenic acidification of these catchments.     

Monitoring endemic plant extinction in Veracruz, Mexico

We present species extinction information based directly on field work on six endemic vascular plants of Veracruz. Amongst 22 species that have been reported to consist of very few individuals for the State, seven of them are endemic to Veracruz. We looked for six of these species in previously recorded sites to determine if they are totally extinct. We determined the status of the extant species and their actual habitat and populations. The species studied included: Antirhea aromatica, Diospyros riojae, Eugenia mozomboensis, Impatiens mexicana, Hyperbaena jalcomulcensis and Zamia inermis. We located these in fragments of tropical and dry forests. Juvenile plants of the Zamia and Eugenia were not seen in the field.     

Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico

Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico. During two and a half years (2003-2005) we recorded the insect species used as food at Zongolica, Veracruz State, Mexico. Interviews were made among people (200) of this municipality to know which insects they consumed. The total of registered species was 57 (Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera and Hymenoptera). The Orthoptera was the most frequently ingested. Twenty-four of these species were new records for edible insects of Mexico. They are eaten in immature stages or as adults, generally only roasted. Consumption is seasonal. Some species are commercialized in the "tianguis" (little town markets) and/or in the larger Zongolica market. There is a "protoculture" of three species, one cockroach (Periplaneta australasiae Fabricius) and two moths (Latebraria amphipyroides Guenée and Arsenura armida armida Cramer). In Zongolica, anthropoentomophagy is an ancestral habit.     

The fishes of northern and central Veracruz,Mexico

The hydrographic structure of Abra Harbour, a tidal embayment located at the seaward end of the highly polluted estuary of Bilbao, is influenced by the inflow of a polluted estuarine plume, the asymmetry of the harbour basin, and the tidal circulation pattern. Multivariate analysis of the spatial variability of the zooplankton between May 1981 and May 1982 showed that significant differences in zooplankton abundance and species composition occurred from the inner-eastern to the outer-western side, related to the horizontal structure of the system. The annual temperature cycle, however, was the major source of temporal variability, and the seasonal stratification in the water column was responsible for the predominance of vertical differences in zooplankton composition during the spring-summer period. Wind-induced turbulence and tides were other sources of variation. With increasing turbulence (rough sea), the spatial gradients in zooplankton composition were not as clear, and with decreasing tidal height the compositional differences in the horizontal dimension tended to be more evident. Spionid larvae accounted for strong local differences within the Harbour. They were usually segregated from other taxa, and mainly associated to the deeper waters characterized by a greater hydrological instability.     

Seasonal community structure of macromycetes in Veracruz, Mexico

A study of phenological patterns in macromycete communities in Veracruz, Mexico was carried out in order to understand changes in community structure across regions of different vegetation types. Previous studies suggest that similarities in community composition occur when there are similarities in certain geographical and climatological characteristics, however they do not address functional groups or seasonal changes across regions. Macromycete communities in Veracruz showed similar species distribution patterns, but individual assemblages changed structure seasonally, changes that were strongly correlated with rainfall. Interestingly, the number of functional groups (species performing similar ecological functions) was not determined by rainfall, but the distribution of species within functional groups was determined by rainfall. Temperature did not appear to play a role in structuring community diversity at this regional scale. However, temperature and other environmental factors such as pH or light may be the mechanism triggering phenological patterns, and influencing the species pool at localized scales. This work brings new light to fungal community diversity patterns in a largely unknown group of species.     

Movement patterns and ecology of Pteronarcys nymphs (Plecoptera)

SUMMARY. 1. Individually tagged Pteronarcys californica (Newport) nymphs were caught and recaptured over a 3-month period to determine their movement patterns and home range size. Sex/age structure, population density, and food habits (from gut contents) were also recorded. More than 1000 nymphs were tagged of which 256 (25%) were recaptured at least once. Tagged insects were confined to contiguous fast water, cobble riffles. Low velocity, silt-bottomed pools acted as barriers.
2. This stonefly has a 3-year life cycle although only the two oldest nymphet size-classes were tagged. Females were larger than males at all ages. The population sex ratio was skewed 60:40 towards females. Densities averaged 1.7 m⁻²±0.17 SE (range 0–19 m⁻²).
3. Most movements were short, indicating that a majority of the stoneflies stayed within a few meters of their first capture point (mean 1.8 m downstream ±0.51 SE, range 44 m downstream to 40 m upstream). Significant patch size is a stream reach 24 m long that would contain 85% of the average individual's movements. Time between captures averaged 16 d ±0.734 SE (maximum 81 d). Eight individuals were notable for extremely rapid upstream movements ranging from 6 to 22 m d⁻¹.
4. Frequency of movements up and downstream differed significantly between the sexes. Pteronarcys distribution was clumped with certain quadrate representing'zones of attraction.'The stoneflies moved rapidly between zones, then stayed many days in those areas. Movements differed significantly from random walk models.
5. Guts contained 75% diatoms, 15% vascular plant material, and 8% animal remains. Females ate significantly more diatoms than males on a volumetric basis.     

Temporal and Spatial Development of Papaya Ringspot in Veracruz, Mexico

The temporal progress and spatial distribution of papaya ringspot virus (PRV) and populations of aphid vectors were monitored in two papaya (Carica papaya) plantations in the state of Veracruz, México. The incidence of PRV had a typical sigmoidal curve and the logistic model was more acceptable for describing the disease progress than the Gompertz model. The rate (r^L of increase in disease incidence (0.034 and 0.023/unit/day in Plot A and B, respectively) differed (P = 0.05) between the plots; differences in number of aphids trapped could account for the difference. The initial determination of an apparent regular spatial pattern early in the epidemic, obtained with a quadrat size determined by Greig-Smith's method (n = 8 plants/quadrat) at 50 % disease incidence, was inconsistent with our biological observations in the field. An arbitrarily selected, square quadrat size (n = 9 plants/quadrat), was more consistent with visual observation for describing the spatial pattern in the field. With 9 plants/quadrat a random pattern was found. Aphid populations had a bimodal distribution at both sites with the highest population peak in December–February and a secondary peak in August–September and change in disease incidence was generally related to the aphid population level in the previous month. None of the five potential aphid vectors (Myzus persicae, Aphis gossypii A. nerii, A. citricola and Macrosiphon euphorbiae) of PRV in Mexico colonized the papaya plants, however, which may explain the absence of clustering of disease.     

Schaueria calycobractea (Acanthaceae), a new species from Veracruz,Mexico

Schaueria calycobractea, a new species of Acanthaceae from Mexico and a genus new to the Mexican flora is described. Pollen morphology of the new species is discussed with reference to generic and tribal concepts in the family.     

A new species of Ponthieva (Orchidaceae, Cranichidinae) from Veracruz, Mexico

Ponthieva rinconii, a new orchid species from the foothills of the Sierra Madre Oriental in Veracruz, Mexico, is described and illustrated. It is similar in overall appearance to the wide-ranging upland speciesP. schaffneri, but differs from it in habitat preferences (tropical semi-evergreen forest at 650 m elevation), presence of a loose raceme, and three-lobed labellum with a basal cavity.     

A new species of Ceratozamia (Zamiaceae, Cycadales) from Veracruz, Mexico

Ceratozamia huastecorum sp. nov. is from an isolated meseta or tepui-like mountain in the Huasteca region of northern Veracruz State, Mexico. It has affinity to C. morettii Vázq.Torres & Vovides from the Mexican transvolcanic mountain range, which lies over 200 km to the south. The most notable differences are in female cone colour, leaf and leaflet morphology and length. The specific epithet is chosen in honour of the Huasteca ethnic region of great cultural importance to northern Veracruz.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 395–398.     

Helminths from the fish Dormitator maculatus (Osteichthyes: Eleotridae) from Alvarado, Veracruz, Mexico

Dormirator maculatus (n=184) was collected in the Alvarado Lagoon, Mexico during a year period (Oct. 1993-1994). In the helminthologic review, the presence of Clinostomum complanatum (82.3%), Neoechinorhynchus golvani (76.1%), Spiroxys sp. (21.3 %), and Camallanus sp. (6.2%) was registered. Reduction of the hematocrit caused by such infection is significant (t, a= 0.05).     

New mayfly nymphs from the Jurassic of Northern and Northeastern China (Insecta: Ephemeroptera)

Four new species of mayfly nymphs, Furvoneta relicta sp. nov., Clavineta eximia sp. nov. (originally Mesoneta antiqua), Mesobaetis latifilamentacea sp. nov., and Stackelbergisca cylindrata sp. nov. are described from the Jurassic of China. All these species may have inhabited lakes rather than flowing water. The geological age and stratigraphical correlation of the nymph-bearing strata are briefly reviewed.