Abstract: The southern African species of the Aradidae subfamily Carventinae are revised, resuhing in the recognition of 7 genera, 24 species and 10 subspecies (excluding the nominal ones). Of these, 4 genera, 18 species and 10 subspecies are described as new. A neotype is designated for Dundocoris natalensis. Keys to the genera and species are given. Scanning electron photomicrographs of the dorsal and ventral aspects and external genitalia are provided for all the species. The cytogenetics...
Abstract: Malaria continues to be among the top leading causes of illness and deaths in Africa. Its elimination is challenging in high transmission areas using insecticide-based intervention tools alone. Understanding the ecology and behaviour of disease vectors, including the olfactory cues, are essential for the development of novel, insecticide-free control tools. Recent work has highlighted that selected graminoid plants release volatile chemicals that attract malaria vectors. However, t...
Abstract: The rate and the degree of reversible change in the phase characteristics of the desert locust, Schistocerca gregaria (Forskal), on crowding and uncrowding have been compared by two new parameters, aggregation pheromone titre (as measured by released phenylacetonitrile) and haemolymph pigment composition (as measured by absorbance ratio at 460 and 680nm) with colour and morphometrics. Changes in the four parameters followed different patterns. Adults of the F0 generation resulting ...
Abstract: The Malagasy migratory locust, Locusta migratoria capito (Saussure, 1884), is the most destructive pest in the Malagasy agricultural production system. The recent plague between 1996 and 2000 during which economic losses amounting to ca. US$ 50 million mainly in rice fields, were recorded, is an indication that, the locust menaces is far from being resolved in Madagascar. Control operations against locusts have focused entirely on large-scale application of synthetic chemical insec...
Abstract: A comparison of the resistance/susceptibility levels of ten cowpea cultivars to the pod borer Maruca testulalis revealed that VITA l was the most susceptible. TVU 946 most resistant and VITA 5, chola local and kamboinse local rroderately resistant. In all the cultivars which were compared, flowers and pods suffered the heaviest damage compared to the stems. Colonizing responses of M. testulalis namely oviposition, larval orientation, feeding, utilization of ingested food, larval de...
Abstract: Laboratory investigations were carried out to assess phytophagy and its effects on the biology of phlebotomine sandflies and their capacity to transmit Leishmania parasites. Preliminary trials to determine the optimum working standards in terms of anthrone concentration, exposure period and duration, effect of sandfly species and/or sex and effects of diets on the feeding rate, led to the choice of 1.25% as the concentration (w /v) of anthrone reagent to detect the presence of suga...
Abstract: A comparative study of the ecology of mosquito vectors of malaria was carried out in the Parkerra irrigation scheme and the Loboi swamp in Baringo districy, Kenya. The swamp was found to be more productive than the irrigation scheme both in terms of species diversity and the relative abundance of individual mosquito species.
Abstract: The oviposition behaviour of Maruca testul ali s on host plant (cowpea), non-host plant s (cotton and sunhemp), and artificial substrates (filter , butter, crepe, and aluminium foil papers) was observed in laboratory and field. These studies were carried out with the aim of gathe ring data on oviposition behaviour patterns e s pecia l ly on how the ovipositing female inter acts with host pla nts, non- host plants as well as potential artificial oviposition substrates. It was also i...
Abstract: Biochemical methods have been applied to elucidate the species systematics of cassava green mite (CGM). Traditionally CGM have been classified using the length of the dorso-central setae (D1-o3 ), which groups CGM into two species, the short setae form, Hononychellus tanajoa (Bandar) and the long setae form Mononychellus progresivus Doreste. However the validity of this method of classification is being questioned because the setae were found to vary from short to long in a continu...