Environmental & Physical Sciences

Research Papers/Topics Environmental & Physical Sciences

Mechanisms and control of secretion in the Malpighian tubules of Tenebrio molitor : an immunohistochemical and electrophysiological study

Abstract: Fluid secretion by insect Malpighian tubules is controlled by haemolymph-bome factors. Two corticotropin-releasing-factor (CRF)-related diuretic peptides, Tenmo¬DH37 and Tenmo-DH47. previously isolated from Tenebrio molitor, were found to stimulate in vitro tubule preparations of Tenebrio molitor via the second messenger cyclic AMP. The stimulatory effect of Tenmo-DH37 was reversed on addition of endogenous antidiuretic peptides (Tenmo-ADFa and ADFb) and exogenous cardioaccelerato...

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...


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