Characterization of polymorphic microsatellite markers in the Indian meal moth,Plodia interpunctella (Hübner)

The Indian meal moth, Plodia interpunctella (Hübner), is a serious and widespread pest of stored food commodities worldwide. Studies on the population genetics and breeding structure of P. interpunctella are lacking. Understanding the breeding structure of this pest has implications for its management. Fifteen microsatellite loci were isolated, cloned and characterized using an enrichment method. Forty individuals from six subpopulations were tested for polymorphism. Nine loci were found to be polymorphic. The number of alleles varied from three to six per locus.     

Structural Equation Modeling for Observational Studies

Abstract Structural equation modeling (SEM) represents a framework for developing and evaluating complex hypotheses about systems. This method of data analysis differs from conventional univariate and multivariate approaches familiar to most biologists in several ways. First, SEMs are multiequational and capable of representing a wide array of complex hypotheses about how system components interrelate. Second, models are typically developed based on theoretical knowledge and designed to represent competing hypotheses about the processes responsible for data structure. Third, SEM is conceptually based on the analysis of covariance relations. Most commonly, solutions are obtained using maximum-likelihood solution procedures, although a variety of solution procedures are used, including Bayesian estimation. Numerous extensions give SEM a very high degree of flexibility in dealing with nonnormal data, categorical responses, latent variables, hierarchical structure, multigroup comparisons, nonlinearities, and other complicating factors. Structural equation modeling allows researchers to address a variety of questions about systems, such as how different processes work in concert, how the influences of perturbations cascade through systems, and about the relative importance of different influences. I present 2 example applications of SEM, one involving interactions among lynx (Lynx pardinus), mongooses (Herpestes ichneumon), and rabbits (Oryctolagus cuniculus), and the second involving anuran species richness. Many wildlife ecologists may find SEM useful for understanding how populations function within their environments. Along with the capability of the methodology comes a need for care in the proper application of SEM.     

Characterization of microsatellite loci in the house fly,Musca domestica L. (Diptera: Muscidae)

The house fly, Musca domestica L., is a cosmopolitan species with a capacity to transmit human pathogens. Here, we report on the development of polymorphic microsatellite loci for house flies and present preliminary results from four house fly subpopulations from Manhattan, Kansas. Twenty‐four microsatellite loci were isolated and characterized using DNA enriched for repeat sequences. Forty individuals from four locations in Kansas were assayed to identify for polymorphic loci. Eight loci were polymorphic with the number of alleles ranging from three to six.     

Fluxes of carbon dioxide and water vapour over an undisturbed tropical forest in south-west Amazonia

• 1 Carbon dioxide and water vapour fluxes were measured for 55 days by eddy covariance over an undisturbed tropical rain forest in Rondonia, Brazil. Profiles of CO₂ inside the canopy were also measured.
• 2 During the night, CO₂ concentration frequently built up to 500 ppm throughout the canopy as a result of low rates of exchange with the atmosphere. In the early morning hours, ventilation of the canopy occurred.
• 3 Ecosystem gas exchange was calculated from a knowledge of fluxes above the canopy and changes of CO₂ stored inside the canopy. Typically, uptake by the canopy was 15 μmol m^?2 s^?1 in bright sunlight and dark respiration was 6-7 μmol m^?2 s^?1 The quantum requirement at low irradiance was: 40 mol photons per mol of CO₂.
• 4 Bulk stomatal conductance of the ecosystem was maximal in the early morning (0.4-1.0 mol m^?2 s^?1) and declined over the course of the day as leaf-to-air vapour pressure difference increased.

     

The Measurement and Interpretation of Ultrasound from Woody Stems

A system for detecting and counting ultrasonic acoustic emissions(AEs) from woody stems in the waveband of 0.1–1.0 MHzis described. AEs from small pieces of stems of Mains sylvestrisand Chamaecyparis lawsoniana occurred up to a rate of 6000 min^–1,and could be related to the water loss as the stems dried. AEsdid not occur randomly, but were aggregated. Each event is interpretedas a single cavitation occurring in the water within a tracheidor fibre. AEs could be temporarily stopped by rewetting thetissue or cutting it to release tension. From knowledge of thenumber of cells in the stems, the fraction of total counts pernumber of tracheids or fibres present in the stem was calculated.This was found to be less than 0.16. One reason why this fractionis so low is that AEs may occur simultaneously; it is also probablethat some AEs emit energy outside the waveband studied. Eventhough the fraction of AEs recorded is low, this instrumentcould prove to be a very powerful tool for investigating theoccurrence of cavitation in woody stems. Key words: Ultrasound, Cavitation, Wood     

A phylogeny of sand flies (Diptera: Psychodidae: Phlebotominae), using recent Ethiopian collections and a broad selection of publicly available DNA sequence data

Sand flies in the psychodid subfamily Phlebotominae carry important human pathogens in the trypanosomatid protozoan genus Leishmania (Cupolillo). Despite the fact that hundreds of sequences for this group are now publicly available, they constitute different sets of taxa and genetic markers. Integrating these data to construct a molecular phylogeny of the family is a significant bioinformatics challenge. We used sequences of eight markers obtained from freshly collected sand flies from Ethiopia and combined them with over 1300 publicly available sequences, performing a combined analysis after generating single terminal sequences from ancestral reconstructions for some individual markers. The resulting phylogeny had 113 terminals and recovered Phlebotominae and certain species groups as monopheletic. Although the 20 outgroups in Psychodinae were recovered as a well‐resolved clade with bootstrap support for many internal clades, Phlebotominae was recovered as several lineages with unclear relationships among them. However, phlebotomines clustered by geographic region, the most notable being all the New World species except Brumptomyia (Galati), which were recovered as monophyletic. Our phylogeny suggests a Sub‐Saharan African or South Asian origin for the subfamily, which subsequently expanded to the north and west, and eventually to the New World. Supported species groups are often composed of widespread species with overlapping ranges. This result highlights the need for a large increase in the amount and diversity of molecular sequence data, and a broad selection of terminals, to test taxonomic hypotheses and examine speciation processes in this important group of flies.     

The prolonged growth and survival of ovarian tissue of the promethea moth (Callosamia promethea) in vitro

1. The ovarian tissues from diapausing pupae of the promethea moth (Callosamia promethea) have survived and grown for 186 days under in vitro conditions. There was continual cell migration and multiplication for a period of 53 days, followed by a period of 47 days during which no cells migrated from the tissues. Between the 100th and 105th days after setting up the cultures, cell migration was resumed, and by the 111th day 250 cells were present in the medium. A few cell divisions were observed between the 126th and 136th days. After the tissues were subcultured on the 140th day, the explant culture continued to survive, but the cell culture died 3 days later. 2. The tissues were subcultured a total of 6 times during the 186 days. By the introduction of a piece of live tissue into the cell cultures, the growth and survival of the cells were increased from 8 days to about 20 days. 3. It is possible that the tissues had become adapted to the medium during their long survival, as the cells which migrated from them after 100 days showed considerably longer survival than those in earlier cultures.     

Genome sizes of cyclopoid copepods (Crustacea): evidence of evolutionary constraint

Genome sizes for 36 species of cyclopoid copepods were determined by DNA-Feulgen cytophotometry of nuclei from adults collected from diverse habitats and locales in North America, South America, Europe, and Asia. Genome sizes are small, show a 20-fold range ( C  = 0.10–2.02 pg DNA), and vary in a discontinuous fashion. The genomes of cyclopoid copepods are remarkably small and constant within each species, unlike the large and variable genomes of marine calanoid species. These differences may reflect the evolutionary antiquity of marine copepods in relation to marine, brackish, and freshwater copepods, as well as differences in mechanisms used to modulate genome size. The small genome sizes of contemporary cyclopoids provide substantive evidence of evolutionary constraint, possibly favouring small genomes, rapid replication rates and accelerated development as adaptive strategies for survival in often fragmented, stressful, and changing habitats. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 625–635.     

The Physiology of Rooting Populus Cuttings

The changing levels of carbohydrates and the rates of photosynthesis in rooting Populus cuttings are described. The cuttings were planted in a sand medium, in controlled environment conditions. There was no evidence to support the view that failure to root in P. tremula was caused by insufficient carbohydrate reserves. In leafless hardwood cuttings, the carbohydrate levels were initially very high (14–19%) but fell rapidly (to 5–10%) as roots, callus or shoots developed. In leafy softwood cuttings, a steady accumulation of carbohydrate reserves was observed, rising from 5–10% on planting to 15–25% when roots had developed. One of the differences between the easy-to-root P. × euramericana and the hard-to-root P. tremula was the apparent downward transport of assimilates in P. × euramericana softwood cuttings.