Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

Embryo-larvicidal activities of lufenuron on selected lepidopteran pests

Abstract: Please read the abstract in the section 00front of this document

Digestion of maize and sunflower pollen by the spotted maize beetle Astylus atromaculatus (Melyridae)

Abstract: The relationship between beetles and flowers is often mutually beneficial. Flowers provide not only edible rewards and favourable micro-environments, but may also be sites for mating and egg-laying activities. Even though beetles consume various parts of flowers, including pollen, and can sometimes cause considerable damage, they are in fact important pollinators of many flowers. Pollen was once considered indigestible but is actually a highly nutritious food source for many animal...

Phylogeography of Scarabaeus (Pachysoma) Macleay (Scarabaeidae: Scarabaeinae)

Abstract: Scarabaeus (Pachysoma) consists of 13 flightless dung beetle species endemic to the arid west coast of southern Africa. Scarabaeus (Pachysoma) are unique in their feeding and foraging habits, in that they randomly search for dry dung/detritus which, when found, is dragged forwards, and buried in a pre-constructed holding chamber, as opposed to the convention of rolling it backwards. This action is repeated to provision the chamber after which the nest is expanded to below the moist...

Climate change and tick-host relationships in Africa

Abstract: Please read the abstract in the section 00front of this document

Tick-host interactions in Hyalomma species

Abstract: Please read the abstract in the section front of this document

Coastal dune forest regeneration : the response of biological communities to rehabilitation

Abstract: Human appropriation of natural resources, and the consequent loss of habitats, means that ecological restoration may in the future become a vital conservation tool. For this to happen, we have to understand the processes and factors that govern community assembly, and their management. Here I analyze data on community structure (richness, evenness, diversity, composition) of assemblages (millipedes, spiders, dung beetles, plants, birds, rodents), and on soil chemical and physical p...

Bioecology of the mango mealybug, Rastrococcus iceryoides green (Hemiptera : Pseudococcidae) and its associated natural enemies in Kenya and Tanzania

Abstract: Rastrococcus iceryoides Green (Hemiptera: Pseudococcidae), an alien invasive mealybug pest of Asian origin was first detected in Tanzania in 1989. This pest rapidly spread by the mid-1990s and was soon present in Coastal Kenya and Northern Malawi, where it has been regarded and remains a major pest of mango. Because of its novelty status, there was no information on its biology, ecology and its natural enemies that could aid development of management efforts. This study, therefore,...

Fungus gnats in forestry nurseries and their possible role as vectors of Fusarium circinatum

Abstract: There are many examples of associations between insects and fungi. Where the fungi involved are pathogens, such associations may be of economic importance. Insects of no economic concern alone can also become important pests because of their association with fungal pathogens. Insects may assist in the spread of pathogens by carrying them on or in their bodies. Insects may also predispose plants to infection by creating wounds during feeding, oviposition or other behavioural activit...

The reproductive biology of Cryptomys hottentotus pretoriae (Rodentia: Bathyergidae)

Abstract: Please read the abstract in the section 00front of this document

A systematic revision of the Bathyergidae (Rodentia) of Southern Africa

Abstract: Please read the section 21chapter20, (Summary and conclusions), of this document

Development of molecular techniques to identify mealybugs (Hemiptera: Pseudococcidae) of importance on grapevine in South Africa

Abstract: Mealybugs (Hemiptera: Pseudococcidae) cause severe damage to many commercial crops, including grapevine. This is largely because of their ability to transmit various grapevine viral diseases, in particular grapevine leafroll-associated viruses (GLRaVs). Grapevine leafroll is one of the most wide-spread grapevine diseases worldwide. Managing the field-spread of grapevine leafroll disease requires, amongst others, stringent mealybug control. Mealybug monitoring and control methods re...

The ecotoxicity of five insecticides to the Pheretima group (Oligochaeta) occurring on golf courses in the Pretoria region (South Africa)

Abstract: Earthworms have an important role to play in turfgrass. They aerify and enrich the soil, enhance water infiltration and break down thatch. Turfgrass managers are advised to select pesticides non-hazardous to earthworms to maintain the long-term stability of a healthy turf An artificial soil test was used to assess the toxicity of five insecticides, used for turf grass pest management, on the Pheretima group (Megascolecidae). The recommended application rates of carbaryl, chlorpyrif...

Diagnostic and phylogenetic character variation in the genus Canthon Hoffmannsegg and related genera (Coleoptera: Scarabaeidae: Scarabaeinae)

Abstract: Morphological variation was examined in 58 species of Canthon and 18 species of other genera of the subtribe Canthonina (Anisocanthon, Canthonella, Cryptocanthon, Deltochilum, Hansreia, Holocanthon, Malagoniella, Melam canthon, Scybalocanthon, and Sylvicanthon). A total of 667 specimens was used for examination of morphological characters. Variation in head structures such as clypeus, eyes, labium, gula, and epipharynx is described. Thoracic structures examined include the pronotum...

Temporal composition of total soluble phenolic content in Eucalyptus leaves in South Africa

Abstract: In South Africa the genus, Eucalyptus plays an important role as a major economic component in the forest and mining sector. Unfortunately, this genus has problems due to damage by pests. The Eucalyptus snout beetle, Gonipterus scutellatus, feeds and defoliates the leaves of eucalypts. Plants produce secondary metabolites, which protects them against defoliation by insects and herbivores. This study focuses on the variations of total soluble phenolic content of nine Eucalyptus spec...


166 - 180 Of 2176 Results