The detection of apple chlorotic leafspot virus by a modified procedure of enzyme-linked immunosorbent assay (ELISA)

The technique of enzyme-linked immunosorbent assay (ELISA) was modified to enable detection of apple chlorotic leafspot virus (CLSV) both in herbaceous hosts and in several naturally infected fruiting and ornamental woody host species. Some of the characteristics of the modified method as used with different virus-host combinations are described.     

Development of Haemogregarina boueti in the toad Bufo regularis*

SYNOPSIS. Haemogregarina boueti França, 1910, was found to be the commonest blood parasite in the common toad, Bufo regularis Reuss, in Egypt. The rate of infection was about 30% (of 689 toads examined). In properly fixed blood films, the parasites were almost exclusively intraerythrocytic. Most characteristic was the encapsulated “elongate” form averaging 22.3 by 6 μ with a more-or-less central nucleus and a pointed, slightly bent, posterior end. Infected red cells were conspicuously hypertrophied and their nuclei were markedly displaced and frequently broken into 2-4 parts. Young and growing blood forms as well as two types of hepatic schizonts are described for the first time. Schizonts of the first type develop in hepatic cells, are 28–30 μ in diameter and produce numerous elongate oval merozoites about 8 × 2.2 μ radially arranged around a residual body about 10 μ in diameter. Schizonts of the second type start their growth in erythrocytes but later complete their development as free bodies in the liver sinusoids. When mature, they are 32–35 μ in diameter and produce a larger number of thin merozoites about 8 × 1.5 μ, surrounding a larger residual body about 19 μ in diameter.     

A comparison,by sweep sampling,of the arthropod fauna of secondary vegetation in Michigan,England and Costa Rica

• 1 Six 800-sweep samples of English and Michigan (“old field”) secondary vegetation arthropods are compared with Costa Rican samples taken in the same way.
• 2 Parasitic Hymenoptera and spiders accounted for a larger proportion of the arthropod fauna in the mid-latitude than the tropical samples.
• 3 In one English field, the seasonal change in insect numbers was 88% of that recorded over all the seasonal and elevational changes examined in Costa Rica. Furthermore, the difference in the total dry weights of the arthropod fauna between December and July was similar to the difference found between the wet and dry seasons in tropical secondary vegetation (also similar to the difference between day and night values during the dry season).
• 4 Aphids and Psyllidae were far more abundant in the English site than in the Costa Rican mainland sites.
• 5 In mid-summer, the English field had far more arthropods in it than did any of the tropical sites sampled.

     

Life cycle assessment of biofuels from Jatropha curcas in West Africa: a field study

In recent years, liquid biofuels for transport have benefited from significant political support due to their potential role in curbing climate change and reducing our dependence on fossil fuels. They may also participate to rural development by providing new markets for agricultural production. However, the growth of energy crops has raised concerns due to their high consumption of conventional fuels, fertilizers and pesticides, their impacts on ecosystems and their competition for arable land with food crops. Low-input species such as Jatropha curcas , a perennial, inedible crop well adapted to semiarid regions, has received much interest as a new alternative for biofuel production, minimizing adverse effects on the environment and food supply. Here, we used life-cycle assessment to quantify the benefits of J. curcas biofuel production in West Africa in terms of greenhouse gas emissions and fossil energy use, compared with fossil diesel fuel and other biofuels. Biodiesel from J. curcas has a much higher performance than current biofuels, relative to oil-derived diesel fuels. Under West Africa conditions, J. curcas biodiesel allows a 72% saving in greenhouse gas emissions compared with conventional diesel fuel, and its energy yield (the ratio of biodiesel energy output to fossil energy input) is 4.7. J. curcas production studied is eco-compatible for the impacts under consideration and fits into the context of sustainable development.     

Haemogregarina faiyumensis n. sp. in the Toad Bufo regularis in Egypt*

SYNOPSIS. Haemogregarina faiyumensis n. sp., a parasite of toads, Bufo regularis, in Faiyuni Province, Egypt, U.A.R., is described. In a survey of 689 toads from various localities in Cairo, Giza and Faiyurn provinces, only 3 out of 13 toads from Kom O Shim near Faiyum were infected. This species, known only by blood forms (most probably gametocytes) of two different staining reactions, is 13-17 μ long and 4-5 μ wide, with an average of 15.5 × 4.5 μ. The nucleus is typically subcircular and 3-5 × 3–5 μ, with an average of 4.5 × 3.9 μ.     

Wolf Predation Among Reintroduced Przewalski Horses in Hustai National Park,Mongolia

ABSTRACT Depredation by wolves (Canis lupus) could threaten survival of reintroduced wild Przewalski horses (Equus ferus przewalskii) in Hustai National Park (HNP), Mongolia. We conducted scat analysis, spatial analyses of kills, and interviews to study prey species selection and temporal and spatial factors that characterize prey choices of wolves. Diet of wolves in HNP was comprised of >50% of livestock. Diet composition varied during the year, with more livestock taken in winter. Wildlife species were selected over livestock species. From available livestock species domestic horses were predated most, whereas red deer (Cervus elaphus) and marmot (Marmota sibirica) were the preferred wildlife species. Our spatial analyses showed an unexpected significant positive relation between number of domestic horses killed and distance to the park, as well as a significant negative relation with number of gers (tents) in the area. Compared to randomly selected comparison sites (n = 36), we found Przewalski foal kills (n = 36) at sites that were closer to the forest, at higher altitudes, with lower shrub cover, higher forest cover, and higher red deer density. If the negative trend of deer numbers continues and if herdsmen protect their livestock more vigorously, depredation of wild Przewalski horses by wolves will rise. Therefore, a large red deer population could be pivotal in improving the conservation status of Przewalski horses.