Telmapsylla gen.n., an unusual psyllid from black mangrove in Florida and Costa Rica (Insecta, Homoptera, Psylloidea)

Telmapsylla minuta . gen. et sp.n., a diminutive species of psyllid collected from black mangrove, Avicennia species (Verbenaceae), is described from Florida and Costa Rica. Telmapsylla is particularly significant in that it possesses characters currently used to define both the families Psyllidae and Calophyidae. Its taxonomic position and host-plant relationships are discussed. Telmapsylla is most probably a primitive calophyid.     

Divergent host preferences of above‐ and below‐ground Culex pipiens mosquitoes and their hybrid offspring

Culex pipiens form pipiens and Cx. pipiens form molestus (Diptera: Culicidae) belong to a cosmopolitan taxonomic group known as the Pipiens Assemblage. Hybridization between these forms is thought to contribute to human transmission of West Nile virus (WNV) in North America. Complementary choice and no‐choice landing assays were developed to examine host acceptance by North American Cx. pipiens in the laboratory. Populations collected from above‐ and below‐ground sites in suburban Chicago were identified as forms pipiens and molestus using a polymerase chain reaction‐based assay. Avian and human host acceptance was then quantified for the two populations, as well as for their hybrid and backcross offspring. No‐choice tests were used to demonstrate that both the pipiens and molestus forms were capable of feeding on human and avian hosts. Choice tests were used to demonstrate that form pipiens females were strongly avian‐seeking; an individual's probability of accepting the chick host was 85%. Form molestus females were more likely to accept the human host (87%). Rates of host acceptance by F₁ and backcross progeny were intermediate to those of their parents. The results suggest that host preferences in Cx. pipiens are genetically determined, and that ongoing hybridization between above‐ and below‐ground populations is an important contributor to epizootic transmission of WNV in North America.     

CONSUMER PREFERENCE OF DULCE DE LECHE AMONG STUDENTS IN THE UNITED KINGDOM

Dulce de Leche is a dairy-based confectionary product virtually unknown outside Latin America. A 2⁴ factorial design was implemented to study the influence of sugar composition, type of neutralizer, cooking time and presence of vanilla essence on the preference of Dulce de Leche by UK university students. A fractional factorial pattern was used in sen'ing samples to assessors. Analysis of variance showed that the preferred levels were: 40% replacement of sucrose by glucose syrup, 100% sodium bicarbonate as neutralizer, and no vanilla essence. Cooking time did not significantly affect preference. Partial least squares regression was used to relate preference to sensory profile scores. The correlation was good for appearance and texture, not so for flavor and aftertaste. A mapping technique showed consumers to be uniformly grouped for appearance and texture, not so for flavor. Results from preference and general acceptability were encouraging in promoting this new dairy product in Great Britain.     

Next-generation sequencing and metagenomic analysis: a universal diagnostic tool in plant virology

A novel, unbiased approach to plant viral disease diagnosis has been developed which requires no a priori knowledge of the host or pathogen. Next-generation sequencing coupled with metagenomic analysis was used to produce large quantities of cDNA sequence in a model system of tomato infected with Pepino mosaic virus . The method was then applied to a sample of Gomphrena globosa infected with an unknown pathogen originally isolated from the flowering plant Liatris spicata . This plant was found to contain a new cucumovirus, for which we suggest the name 'Gayfeather mild mottle virus'. In both cases, the full viral genome was sequenced. This method expedites the entire process of novel virus discovery, identification, viral genome sequencing and, subsequently, the development of more routine assays for new viral pathogens.     

Features of the underwater light climate just below the surface in some New Zealand inland waters

1. Using sampling rates of 8–64 Hz we found clear indications of extensive and high frequency fluctuations of underwater photosynthetically active radiation (PAR) just below the surface (0.016–1.1 m) in some New Zealand water bodies. High variability and flashing occurred down to at least 3 m depth.
2. PAR variability increased under the influence of bright sunshine if wind roughening of the surface took place. Concomitantly, the average PAR levels declined by about 10%. However, even when the surface was shaded, high variability of PAR persisted.
3. Under a calm surface, PAR irradiance followed a log normal distribution. This occurred independently of the presence of direct sunlight. However, when the surface was roughened by wind in sunshine, PAR immediately switched to a Gumbel (extreme value type EV1) distribution.
4. Neither wave action nor wave focusing of incident irradiance would explain the wide range of PAR close to the water surface, although both factors add to the PAR variability.
5. The data indicate that transmittance through the surface is highly variable at the temporal and spatial scales studied, and that the irregularity of the air–water interface is instrumental in bringing about the observed fluctuations of PAR just below the surface.     

Low genetic diversity and small population size of Takahe Porphyrio hochstetteri on European arrival in New Zealand

The rediscovery of the Takahe Porphyrio hochstetteri in 1948 in the remote mountains of Fiordland, New Zealand, has been described as one of the greatest moments in ornithological history. The subsequent management of the population has become a model for avian recovery programmes, yet questions still remain regarding the population size at the time of, and prior to, its rediscovery. We used 20 microsatellite markers to genotype samples of the three surviving museum specimens (1849–1898) collected prior to the initial declaration of extinction to estimate levels of genetic diversity and effective population size. These estimates were compared with equivalent estimates from DNA samples of three specimens preserved at the time of rediscovery (1949) and with 20 contemporary samples. Using rarefaction simulations to account for the limited sample sizes, the results suggest that only slightly more genetic diversity (allelic diversity and numbers of polymorphic loci) existed in the earliest Takahe sampled and that levels of genetic diversity at the time of rediscovery were very similar to those today. Effective population size estimates showed a similar pattern. Contemporary samples from a widespread congener to Takahe, the Pukeko Porphyrio porphyrio, showed consistently higher levels of genetic diversity and greater effective population size, even after equivalent rarefaction to the same small sample sizes available for Takahe. It is likely that the population size of Takahe in Fiordland at the time of European arrivals in the 1800s was similar to its current size. These results provide molecular support for the hypothesis that Takahe were common throughout most coastal and eastern parts of the South Island of New Zealand before being hunted to extinction in these regions by early Maori, and persisted as a relatively small and isolated population in Fiordland where they may never have been very common. This is in marked contrast to other New Zealand endemic birds found in Fiordland, such as the Kakapo Strigops habroptilus and several forest passerines, which remained relatively numerous until the time of European arrival before undergoing rapid declines thereafter.     

The effects of increasing mandibular load on electrical activity in the mandibular closer muscles during feeding in the desert locust, Schistocerca gregaria

ABSTRACT. Electrical activity from individual mandibular closer muscle fibres of the desert locust Schistocerca gregaria was monitored during three feeding conditions: chewing soft grass, chewing soft grass against an artificial load, and chewing an incompressible grass. Spiking frequency during bursts of activity was found to increase under conditions of increased artificial, and natural load. These increases in spiking frequency occurred over a frequency range much lower than that necessary to produce a maximal tetanic contraction, and therefore correspond to increases in power output by the closer muscles in response to increases in load. A possible mechanism for this is described.