Resistance of nine cabbage (Brassica oleracea van capitata) cultivars, Big cropper, Cape Spitz, Copenhagen Market, Conquistador, Drumhead, Giant Drumhead, Glory of Enkhuizen, Grandslam and Hercules to cabbage aphid (Brevicoryne brassicae) was studied in greenhouse experiments conducted at the Botswana College of Agriculture, Gaborone, Botswana. Cabbage aphids caused 85 % leaf damage on the most susceptible cultivar, Drumhead, and only 30.9 and 44.6 % on the more resistant cultivars, Grandslam and Copenhagen Market, respectively. Drumhead had the lowest number of aphids per leaf, showing the antibiosis mechanism of resistance to B. brassicae and yet it suffered the most severe damage. Although Copenhagen Market was resistant to cabbage aphid damage, it had the greatest abundance of aphids per leaf, showing that it used the tolerance resistance mechanism against cabbage aphids. Conquistador, Glory of Enkhuizen, Grandslam and Hercules, which gave the lowest combined effect of number of aphids multiplied by percentage damaged leaves per plant were the best varieties for use by farmers. However, since they only achieved partial resistance to the cabbage aphid, their use is recommended in combination with a low dose of insecticide.

Diurnal and lifetime patterns of feeding and reproductive activities of three fruit fly species, Ceratitis cosyra (Walker), C. fasciventris (Bezzi) and C. capitata (Wiedemann) (Diptera: Tephritidae), were studied in cages of increasing scale: laboratory cages, standard field cages and a greenhouse. Consistency of behavioural patterns in different caging systems was assessed. The diurnal feeding patterns of female flies were influenced by type of cage, being uniform throughout the day in laboratory cages and changing to either bimodal or unimodal, depending on species, in the greenhouse. In contrast, feeding patterns of male flies were consistent among caging systems, and were uni-modal in C. fasciventris and C. capitata with a peak in morning and late afternoon, respectively. For both sexes of all species, highest feeding frequencies were recorded in field cages. In all three species, diurnal patterns of reproductive behaviour, such as periodicity of calling and mating (except for oviposition) were not affected by cage type. However, for C. capitata, higher frequency of calling was observed in the greenhouse, while higher frequency of mating was observed in field cages. We discuss the rationale for use of a greenhouse rather than standard field cages for pre-release evaluation of reproductive performance of sterile C. capitata males in SIT programmes.

Adelostoma (s. str.) sdiawalleri sp. n. from Socotra is described and compared with its relatives. Photographs of the habitus, distribution data and an identification key for all the Socotran species of the genus Adelostoma Duponchel, 1827 are provided.

Head capsule widths of the instars of codling moth, Cydia pomonella (Linnaeus), a severe cosmopolitan pest of apples, were measured for laboratory-reared larvae and two cohorts of field-reared larvae. At the same time the accumulated degree days to reach the various instars was estimated. The results show that there were always five distinct instars. By measuring the head capsule width of larvae found inside infested apples and using the degree day data, pest managers can determine the instar, larvae age, and therefore when the fruit was entered. This information may give important clues towards understanding the reasons for control failure.

The presence of the tribe Morphozonitini (Meloidae, Eleticinae) in southwestern Africa is documented and three new taxa are described. Mimiselma pintoi gen. n. and sp. n. from the Angolan Namib shows an extraordinary morphological convergence to some species of the genus Iselma (Eleticinae, Derideini) endemic to the xeric regions of Namibia. Morphozonitis angolensis sp. n. from southwestern Angola represents an isolated element of the genus, which is distributed mainly in eastern and central Africa. Lytta mashuna Péringuey is transferred to the genus Morphozonitis (comb, n.); M. quadrimaculata (Borchmann) is demoted to become a subspecies of M. mashuna (stat. dem.); the subspecies M. quadrimaculata caffer Kaszab is made a junior synonym of the nominotypical subspecies M. mashuna mashuna (syn. n.); and new combinations for two more subspecies are proposed. Information on the colour variability of M. csikii Kaszab from Kenya is given. Finally, a new key to the genera of the tribe Morphozonitini is provided.

The Cetoniinae (Coleoptera: Scarabaeidae) genus Ichnestoma Gory & Percheron, 1833 currently comprises 13 described species and is endemic to South Africa. The species I. stobbiai Holm, 1992 is thought to occur in a very restricted area in and around Gauteng Province. Unlike most cetoniine larvae, the larvae of this species usually occur in dolomitic to cherty, well-drained soils. Here we briefly explain the conservation issues surrounding this species and describe its larvae and pupae.

The genus Kuwanimyia Townsend, before known only from one East Asian species (K. conspersa Townsend) is reviewed. Three new Afrotropical species, K. afra sp. nov., K. atra sp. nov. and K. capensis sp. nov. [the last one a parasitoid of Cossus tenebroides (Lepidoptera, Cossidae)] are described and illustrated. The generic limits of Kuwanimyia are reappraised to exclude Dolichocolon Brauer & Bergenstamm and Prosopodopsis Townsend. A key to the known species of Kuwanimyia is provided.

The floating aquatic fern, Salvinia molesta D.S Mitchell (Salviniaceae) was first recorded in Senegal in 1999 and by 2000 it covered an estimated area of 18 000 ha on the Senegal River Left Bank and tributaries (Senegal) and 7840 ha on the Senegal River Right Bank (Mauritania). The weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) was considered the best option for control and some 48 953 weevils were released at 270 sites during 2002. Within one year, weevils had established and were recovered up to 50 km from the release sites. At most of the release sites, the S. molesta infestation was reduced from 100% to less than 5% within 24 months of release. These results are discussed in the context of the weed's negative impact on aquatic systems.

Malagasy dung beetles have evolved with a diverse group of primates (lemurs), the largest extant native herbivores on the island. The two main radiations include the endemic subtribe Helictopleurina (65 species) and the tribe Canthonini with several endemic genera (c. 170 species), both of which occur primarily in forests and feed on lemur faeces and carrion. Cattle were introduced to Madagascar about 1000 years ago, thereby establishing a completely new type of resource (cattle dung) for indigenous dung beetles. We report three striking patterns in the occurrence of dung beetles in cattle dung based on semi-quantitative sampling at nearly 80 localities across Madagascar. First, no dung beetles have shifted to use primarily cattle dung in wet forests, in contrast to other tropical regions, where ungulate dung is a key resource for dung beetles. Second, the community in open habitats includes 21 species (three Canthonini, six Helictopleurina, one Scarabaeini, four Onthophagini, six Aphodiini, and one Didactyliini), which is only a small fraction of the species number in comparable communities in mainland Africa. Third, nearly all species using cattle dung have maximally large geographic ranges across Madagascar, in marked contrast to relatively small ranges among forest-inhabiting species. This latter point applies also to four endemic Helictopleurina species, which have shifted to cattle dung in open areas and have subsequently expanded their ranges in comparison with their relatives inhabiting forests. The most numerous species in the community is the introduced Digitonthophagus gazella. We show that the abundance of D. gazella in local communities has no noticeable effect on the species composition in the remaining community.

The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is an important cause of stored maize losses in the Western highlands of Cameroon. Chemical insecticides for rapid control are expensive and not readily available. In search for cheap and easily available natural products to control this insect pest, the biological activity of ethanolic extracts of some traditionally used plant materials were evaluated against the weevil. Laboratory studies on toxicity against F₁ progeny, contact toxicity and repellency against S. zeamais were conducted with ethanolic extracts of Vetiveria zizanioides roots, and Cupressus arizonica, Ocimum gratissimum, Eucalyptus grandis leaves. The ethanolic extracts of the last three plant species had significant toxicity (P = 0.01) on S. zeamais and against the F₁ progeny. Percentage repellency was significant across the four plant extracts but highest in grains treated with V. zizanioides. Repellency was concentration-dependent and greater than 50 % at the lowest V. zizanioides extract concentration of 12 500 ppm. Vetiveria zizanioides could be a potential repellent for the protection of stored products against S. zeamais.

What is believed to be the wax scale, Ceroplastes myricae (Linnaeus), has been rediscovered in the region of the type locality in South Africa on the type host plant, Morella quercifolia (L.) Killick (Myricaceae). The adult female is redescribed and illustrated and a neotype designated. In addition, a key to all species of wax scale insect known from South Africa is included.