A spectacular new species of Nepenthes L. (Nepenthaceae) pitcher plant from central Palawan,Philippines

A new species of Nepenthes L., N. attenboroughii (Nepenthaceae), from Palawan Island in the Philippines, is described and illustrated. It is restricted to rocky, ultramafic soils that comprise the summit region of Mount Victoria, Municipality of Narra, where it occurs in isolation from other members of the genus. On the basis of the morphological features, this new taxon appears to be related to both N. mira Jebb & Cheek of Palawan and N. rajah Hook.f. of Borneo. Its substantial size places it among the largest of known pitcher plants. The diagnostic morphological characters are discussed and an updated key is provided for a revised complex of Nepenthes species from the Palawan and North Borneo phytogeographical region. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 195–202.     

An improved method using densitometry for evaluating severity of laser photocoagulation induced CNV

Laser photocoagulation induced choroidal neovascularization currently is the most effective model available for the study of this disease in terms of efficacy of new drugs and therapies. Previously, evaluating the extent of choroidal neovascularization using this model was time- consuming and required the use of experienced personnel. We describe a new method for simple and rapid evaluation of laser induced choroidal neovascularization using densitometry. Fluorescein angiograms of a laser photocoagulated rat eye were scanned into a computer. Densitometry software subsequently was used to calculate the severity of the laser lesions. The densitometry method proved effective for calculating the extent of laser induced choroidal neovascularization. In addition, this method was more rapid than visual evaluations and less likely to produce errors.     

Spread and impact of introduced conifers in South America: Lessons from other southern hemisphere regions

The history of conifers introduced earlier elsewhere in the southern hemisphere suggests that recent invasions in Argentina, Brazil, Chile and Uruguay are likely to increase in number and size. In South Africa, New Zealand and Australia, early ornamental introductions and small forestry plantations did not lead to large‐scale invasions, while subsequent large plantations were followed with a lag of about 20–30 years by troublesome invasions. Large‐scale conifer plantation forestry in South America began about 50–80 years later than in South Africa, Australia and New Zealand, while reports of invasions in South America lagged behind those in the latter nations by a century. Impacts of invading non‐native conifers outside South America are varied and include replacement of grassland and shrubland by conifer forest, alteration of fire and hydrological regimes, modification of soil nutrients, and changes in aboveground and belowground biotic communities. Several of these effects have already been detected in various parts of South America undergoing conifer invasion. The sheer amount of area planted in conifers is already very large in Chile and growing rapidly in Argentina and Brazil. This mass of reproductive trees, in turn, produces an enormous propagule pressure that may accelerate ongoing invasions and spark new ones at an increasing rate. Regulations to control conifer invasions, including measures to mitigate spread, were belatedly implemented in New Zealand and South Africa, as well as in certain Australian states, inspired by observations on invasions in those nations. Regulations in South America are weaker and piecemeal, but the existing research base on conifer invasions elsewhere could be useful in fashioning effective regulations in South America. Pressure from foreign customers in South Africa has led most companies there to seek certification through the Forestry Stewardship Council; a similar programme operates in Australia. Such an approach may be promising in South America.     

Deconstructing Ixodes ricinus: a partial matrix model allowing mapping of tick development,mortality and activity rates

A stage‐structured Leslie matrix model of a partial, discrete population of Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) ticks was developed to elucidate the impact of climate trends on the distribution and phenology of this species in the western Palaearctic. The model calculates development and mortality rates for each instar and evaluates recruitment rates based on the development of the tick population. The model captures the changes in development and mortality rates, providing a coherent index of performance correlated with the tick's geographic range. Maximum development rates are recorded for latitudes south of 36 °N and are spatially correlated with sites of maximum temperature, highest saturation deficit and highest mortality. The maximum available developmental time (the total annual time during which temperature allows development) for I. ricinus in the western Palaearctic is < 45% of the total year. North of 60 °N, available developmental time decreases sharply to only 15% of the year. The latitudinal boundary at which survival rates sharply drop is 43–46 °N, clearly delimiting the classically recognized extent of the main tick populations. The pattern of activity for larval–nymphal synchrony shows a clear west–east pattern. The model demonstrates the impact of climate according to tick stage and geographic location, and provides a practical framework for testing how the tick's lifecycle is affected by climate change.     

The Effect of Population Density on Floret Initiation, Development and Abortion in Winter Wheat

There is little information in the literature concerning thephysiological basis of the relationship between plant populationdensity and kernel number in winter wheat (Triticum aestivumL.). Thus, two experiments were conducted to evaluate this relationship.Expt 1, involving three population densities, was carried outnear Taian, China in 1982 and in Expt 2, two densities wereevaluated near Lexington, Kentucky in 1986. Plants were sampled every 2 d in the spring, main stem spikeswere dissected and florets were scored according to a 10-stagescale of development. The rate of primordia initiation increasedas density increased until the point at which primordia numberswere equal in all treatments. After this point, an increasein density reduced the primordia initiation rate. In both experimentsincreasing density reduced the total number of floret primordiainitiated and the number of kernels per spike. In Expt 1 theeffect of density on kernel number per spike was accounted forapproximately equally by the effect of density on number ofprimordia initiated and floret abortion. In Expt 2, however,floret abortion was influenced much less by density and accountedfor only 7 % of the variation in kernel number per spike. Thekey result was that the effect of density was determined earlyin floral development. The data suggest that yield losses athigh densities may be determined too early in development tobe offset by N applications at the terminal spikelet stage. Triticum aestivum L., spike development, spikelet development, seeding rate     

Long‐proboscid brachyceran flies in Cretaceous amber (Diptera: Stratiomyomorpha: Zhangsolvidae)

The monophyletic family Zhangsolvidae comprises stout‐bodied brachyceran flies with a long proboscis and occurring only in the Cretaceous, originally known in shale from the Early Cretaceous Laiyang Formation (Fm.) in China (Zhangsolva Nagatomi & Yang), subsequently from limestones of the Early Cretaceous Crato Fm. of Brazil. Cratomyoides Wilkommen is synonymized with Cratomyia Mazzarolo & Amorim, both from the Crato Fm.; Cratomyiidae is synonymized with Zhangsolvidae. Two genera and three species of Zhangsolvidae are described: Buccinatormyia magnifica Arillo, Peñalver & Pérez‐de la Fuente, gen. et sp.n. and B. soplaensis Arillo, Peñalver & Pérez‐de la Fuente, sp.n. , in Albian amber from Las Peñosas Fm. in Spain; and Linguatormyia teletacta Grimaldi, gen. et sp.n. , in Upper Albian–Lower Cenomanian amber from Hukawng Valley in Myanmar. Buccinatormyia soplaensis and Linguatormyia teletacta are unique among all Brachycera, extant or extinct, by their remarkably long, flagellate antennae, about 1.6× the body length in the latter species. A phylogenetic analysis of 52 morphological characters for 35 taxa is presented, 11 taxa being Cretaceous species, which supports placement of the family within Stratiomyomorpha, although not to any particular family within the infraorder. This published work has been registered in Zoobank, http://zoobank.org/urn:lsid:zoobank.org:pub:F32CF887‐7C37‐45D5‐BD6B‐135FE9B729A7 .     

Distribution of streptothricin acetyltransferase encodi determinants among environmental bacteria

In this paper we report about a screening for streptothricin- (St)-resistant phenotypes and genotypes among environmental bacteria from a St virgin area. St-resistant bacteria were isolated from river water, sewage, manure and soil by selective plating. The resistance quotient was typical of an area without selective pressure. The occurrence of streptothricin acetyltransferase-encoding determinants and their localization on a Tn7-like transposon was tested by the application of a set of gene probes. Sat genes could be detected in 22.5% of the tested St-resistant bacteria but in 100% of the checked Enterobacteriaceae. However, we could not detect sat genes in St-resistant bacteria from soil samples. Surprisingly the sat genes were found to be located on conjugative or mobilizable plasmids for a rather high number of strains. The determined plasmid species and their restriction patterns showed a high degree of similarities to those observed from an area of strong selective pressure.     

Further Observations on the Fine Structure of the Spores of Glugea weissenbergi (Microsporida,Nosematidae)*

SYNOPSIS. A Glugea xenoma sectioned and viewed with the electron microscope contained many spores with everting polar filaments. Several details not seen in previous studies of this species were observed. A specialized area with the appareance of a lattice was commonly present near the anterior end of the polaroplast. The external portion of a partially everted polar filament appeared to have about twice the diameter of the part remaining within the spore. No membrane was seen limiting the external surface of the everted portion. The everting filament had pushed thru the polar cap and the adjacent thin area of the spore wall, making the polar cap into a ring. The ring connected the proximal end of the everting filament to the inner spore membrane, thereby anchoring the filament to the spore. The electron density of some of the membranous organelles of the spore was enhanced by the use of ruthenium red.     

Fine Structure of the Cyst and Some Sporulation Stages of Ichthyosporidium (Microsporida)*

SYNOPSIS. Ichthyosporidium sp. Schwartz, 1963, apparently identical with the type species, I. giganteum (Thélohan, 1895) Swarczewsky, 1914, was studied with the electron microscope. Only late stages, a mature cyst containing sporulation stages and a cyst in the terminal (necrotic) stage were observed. The cyst, originating from host tissue, is a highly organized structure that is integrated with the surrounding connective tissue by means of numerous conspicuous processes. It is interpreted as essentially a manifestation of a defensive reaction of the host that is elicited by the parasite and then used to its advantage. Eventually the cyst dies and disintegrates. This type of cyst, peculiar among those associated with microsporidia, may be regarded as a distinctive character of the poorly defined genus Ichthyosporidium. Other observations let to an hypothesis which reconciles several different views regarding the identity of the Golgi complex. According to this new interpretation, these different views concern different aspects af the total complex. When all such views are integrated, a “classical Golgi” can be recognized in the presporoblastic stages and the “primitive Golgi” concept disappears. This “classical Golgi” then becomes highly modified during spore morphogenesis, giving rise to many of the internal organelles that are peculiar to the spore.