The new genus Afrolasioptera Dorchin is established for a new gall-midge species, A. tumida Dorchin (Diptera: Cecidomyiidae: Lasiopterini), described from bud galls on Elytropappus rhinocerotis (Asteraceae) in the Western and Northern Cape provinces of South Africa. The new genus is unique for the largely inflated segment 8 of the female abdomen and the laterally flattened and conspicuously setose ovipositor. The species is univoltine and induces common galls in shoot tips, often developing in small groups. This is the fifth species of gall midge to be described from Asteraceae hosts in southern Africa, a region whose rich cecidomyiid fauna is still largely unknown.

The population fluctuations of arthropods attacking table grapes were studied in 12 commercially treated vineyards in the Hex River Valley in South Africa for three years. Sampling was conducted by inspecting different plant parts and using a variety of traps. Planococcus ficus (Signoret) males in the pheromone traps started increasing during December, to reach a peak at the end of February. Cordon infestation preceded bunch infestation by three to five months, the latter occurring from about January or February. Thrips, mainly Frankliniella occidentalis (Pergande), caught on blue sticky traps were active during spring and early summer. Damage to the berries occurred about four weeks after thrips were recorded on the sticky traps. Phlyctinus callosus Boh. was recorded under fluted cardboard bands tied around the stems of vines from early October, with the first bunch damage recorded towards the end of October. More Epichoristodes acerbella (Walker) moths were caught in pheromone traps during the cool winter months than during the hotter summer months. Damage to the bunches started during November and declined during January and February, only to increase again towards the end of February and March. Although Helicoverpa armigera (Hübner) moths were caught in pheromone traps, no damage ascribed to this insect was recorded. The only phytophagous mite was Tetranychus urticae Koch, which was active throughout the fruiting season. The most common predatory mite was Euseius addoensis (Van der Merwe & Reyke).

Gymnopleurus sericatus Erichson, 1843, and its synonym G. modestus van Lansberge, 1886 (not Péringuey), are re-established as synonyms of G. humanus MacLeay, 1821, along with one further synonym, G. modestus Péringuey, 1888 (not van Lansberge) = G. peringueyi Shipp, 1895. G. humeralis Klug, 1855, is removed from synonymy with G. humanus MacLeay and reinstated as a valid species. G. humanus var. azureus Ferreira, 1954, is made a synonym of G. humeralis Klug. The confusion was apparently caused partly by unwitting redescriptions, partly by failure to note previous synonymies, and partly by failure to distinguish between a species centred in the arid southwest (G. humanus and its synonyms) and its larger-bodied, close relative from the mesic northeast of southern Africa (G. humeralis and its synonym). As the Kalahari forms a wide disjunction between the species' ranges, G. humanus (Karoo–Namib) and G. humeralis (dry savanna) may be differentiated by geographical location alone. The past practise of providing names for colour varieties is not considered useful as G. humanus shows the full range in exoskeleton colour variation, from entirely blue to entirely green to entirely cupreous, in the same local populations of the central Northern Cape, South Africa. Type specimens of G. humanus and its synonyms originated either from the southern range extremes (southern Karoo, South Africa) where the populations predominantly comprise blue individuals or from the northern extremes (southwest Angola) where the populations entirely comprise cupreous individuals.

Three tortricid species are of major economic importance to the South African tropical and subtropical fruit industry. They are the false codling moth, Thaumatotibia leucotreta, the macadamia nut borer, T. batrachopa, and the litchi moth, Cryptophlebia peltastica. Identification of these species is essential for phytosanitary purposes and to aid the management of population levels in the field. For this purpose, species identification was investigated using morphological and molecular genetic techniques. For each species, final instar larvae and pupae are described and illustrated. Diagnostic characters are given for each species and keys included to facilitate identification. In addition, as an alternative to morphological identification, a diagnostic 367-bp region of the mitochondrial cytochrome oxidase I (COI) gene was sequenced from individuals of the three species. The inclusion of both morphological and molecular keys provides a reliable means of identifying the tortricids of economic importance on tropical and subtropical fruit in South Africa.

The field biology of subterranean Eriosoma lanigerum (Hausmann) was studied on two farms in the Elgin apple growing area from October 1995 to January 1999. There were two peaks of activity in subterranean E. lanigerum populations, one during early summer and one during autumn. Nitrogen levels in the roots also peaked at these times of the year. All developmental stages were recorded on the roots of apple trees throughout the year. Peak numbers of first instar aphids were recorded during spring. Embryos were present in all instars throughout the year. More embryos were recorded in fourth instar and adult aphids than in the other developmental stages. Peak numbers of embryos were also recorded in the final two developmental stages (fourth instar and adults) during spring. Nitrogen levels were higher in healthy roots and in roots adjacent to galls than in galls.

Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) has been used as a biological control agent of several Opuntia species around the world and is widely assumed to be a generalist on host plants within the genus Opuntia. The recent arrival and spread of C. cactorum on the North American mainland has raised concerns for the native species of Opuntia that are being utilized as hosts by the moth. To confirm that C. cactorum is a threat to a wide range of Opuntia species in North America, the host range of the moths was scrutinized in South Africa, where larval development could be monitored on several Opuntia species under natural conditions. Development was monitored on Opuntia ficus-indica L. Miller, O. engelmannii Salm-Dyke, O. fulgida Englm, O. imbricata (Haworth) de Candolle, O. stricta Haworth and O. leucotrichta DC. Larval survival, egg to pupation, was highest on O. ficus-indica (79.2 %) followed by O. engelmannii (57.5 %), O. stricta (55.0 %), O. leucotrichta (29.2 %), O. fulgida (24.2 %) and O. imbricata (16.7 %). Male and female pupal mass was highest, and duration of development shortest on O. ficus-indica. In adult multi-choice oviposition trials, females laid significantly more egg sticks on O. ficusindica than on the other species. Although O. ficus-indica is the preferred host for C. cactorum in South Africa, the moth is nevertheless able to utilize several other species of Opuntia as hosts.

Field surveys conducted in Argentina proved Plectonycha correntina Lacordaire (Coleoptera: Chrysomelidae) to be a promising biocontrol agent against the Neotropical perennial climber, Anredera cordifolia (Tenore) Steenis (Basellaceae), a serious environmental weed in Africa and Australasia. Larvae and adults feed on the leaves. The host range was evaluated by no-choice larval survival tests and adult feeding and oviposition choice tests. Sixteen plant test species were selected from the Basellaceae (4 species), Portulacaceae (4), Crassulaceae (3), Cactaceae (3) and Aizoaceae (2) families. Larval development could only be completed on species of Basellaceae (A. cordifolia, Anredera krapovickasii (Villa) Sperling, Basella alba Linné, Ullucus tuberosus Caldas). The other test plant species sustained larval development for less than 96 hours. In multiple-choice tests involving plant species outside the Basellaceae, both in the presence and in the absence of A. cordifolia, P. correntina showed an almost complete preference for its natural host. Larvae that emerged from the few eggs laid on Talinum paniculatum (Jacquin) Gaertner (Portulacaceae) and Pereskia grandifolia Haworth (Cactaceae) died within 48 hours, without feeding. In the test among the Basellaceae, feeding and oviposition preference of P. correntina for A. cordifolia and B. alba were significantly higher than for A. krapovickasii and U. tuberosus. In multiple-choice and paired-choice feeding and oviposition tests, and in fecundity tests, P. correntina displayed a significantly greater preference for Madeira vine than for B. alba. The results indicate that the host range of P. correntina is restricted to the Basellaceae, with A. cordifolia as its primary host. Consequently, we consider P. correntina a safe and promising biocontrol agent for Madeira vine in countries such as Australia and New Zealand where no other Basellaceae occur.

Feeding by Nysius natalensis (Hemiptera: Orsillidae) adults on sunflower heads reduces grain yield, oil content and seed germination. Since the insect is known to feed on several host plants, a study was conducted on its host plant range to assess the role that weeds played in the pest status of this insect throughout the sunflower production area of South Africa. Roadside surveys of hosts, conducted in every quarter-degree grid of the sunflower production area, showed that N. natalensis was ubiquitous. The insect survived, developed and reproduced across a wide range of temperature and rainfall conditions. Feeding of nymphs and adults, as well as the presence of eggs was observed on 26 plant species belonging to eight families. The polyphagous habits of N. natalensis, together with a favourable temperature range for development in its distribution area, are important factors in determining population density of the pest. Late-planted sunflowers were prone to N. natalensis damage because seed-fill coincided with high numbers of the insect that increased during spring and summer. These individuals migrated onto sunflower with senescence of host weeds prior to winter. Recommendations are made on weed management practices to limit damage by N. natalensis.

This paper presents the description of the third instar larva and puparium of Eutropha lindneri Sabrosky, based on material reared from mammalian carrion, chiefly the carcasses of Cape fur seals, on the Namibian coast. Descriptions are illustrated with stereoscan micrographs (SEMs) and photographs of diagnostic character states, and the distribution of the species in Namibia is plotted. The association of the Chloropidae with mammalian carrion is briefly discussed, together with the occurrence of the species at inland localities in Namibia. This is the first description of the immature stages for the genus. The species is largely confined to the inter-tidal zone and, in Namibia at least, is apparently restricted to the desert biome.

Alien plants are rapidly invading natural areas in South Africa but their impacts on biodiversity, particularly on arthropods, are poorly understood. We examined the impact of silver wattle, Acacia dealbata, invasion on Coleoptera assemblages in the grasslands of the Drakensberg region, South Africa. Baited pitfall trap samples from uninvaded grassland and grassland sites invaded by A. dealbata were sorted into morphospecies. The composition of Coleoptera assemblages, attracted by cow dung, differed significantly between invaded and uninvaded grassland habitats. Coleoptera richness and especially abundance values were found to be significantly lower in the invaded stands compared to grassland. Mean body size showed significant differences when compared between the two habitat treatments. The invaded sites exhibited a marked decline in the larger and less abundant species. Also, parataxonomic units unique to the grassland were, in general, characterized by larger body sizes compared to those unique to the invaded sites. Clearly, A. dealbata invasion of grasslands has substantial negative impacts on Coleoptera diversity.

Distributional and taxonomic information on flightless insects were used in a cladistic analysis of distributions and endemism (CADE) to generate a testable hypothesis of area-relationships for the central eastern African mountains. A tree was obtained where the relationships of all mountain areas were resolved according to a hierarchical, time-dependent sequence of vicariance events. It is inferred that most of the present species distributions originated as a consequence of forest fragmentation during the Pleistocene cycles of cooling and drying of the climate. Around 150 000–130 000 years ago, Africa experienced colder, dryer conditions than present conditions. This could have been the first stimulus in the last glacial/interglacial cycle for a large vicariance among different mountain systems. About 130 000 years ago, a warmer, moister phase than the present began, and this condition could have represented an important occasion for the widespread distribution of some genera and species among neighbouring mountain systems. The last glacial maximum confined most species to single refugial montane areas. A resumption of warm, moist conditions probably led up to the Holocene ‘optimum’ of greater rainforest extent allowing some species to disperse again among adjacent mountain peaks.

It is essential to assess the environmental risk that Bt maize may hold and to study its effect on species assemblages that fulfil a variety of ecosystem functions. Environmental risk assessment can be improved through the use of an ecological model which can be applied to a specific environment, so that local species can be classified functionally and prioritized to identify potential test species. Although the stem borers, Busseola fusca (Lepidoptera: Noctuidae), and Chilo partellus (Lepidoptera: Crambidae), are the target species of Bt maize in South Africa various other Lepidoptera species are also directly exposed to Bt toxin. In this paper an ecological approach was followed for selection of non-target Lepidoptera species for ecological risk assessment of Bt maize, using data collected over a two-year period on Lepidoptera biodiversity on maize. Nine primary non-target lepidopterous consumers were identified. A selection matrix was developed in which each species was ranked for its maximum potential exposure to Bt toxin by assessing its occurrence, abundance, presence and linkage to other host plants in the maize ecosystem. Non-target Lepidoptera most likely to be affected were identified and prioritized for future testing and inclusion in risk assessments. Several non-target species were prioritized for their close association with maize, general occurrence in the maize-growing regions and their potential for economic damage should they become secondary pests. Through use of the selection matrix, knowledge gaps were identified for future research and guidance for the design of ecologically realistic experiments. Non-target species populations with the highest maximum potential exposure to Bt toxin are Sesamia calamistis (Hampson) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and Acantholeucania loreyi (Duponchel) (Lepidoptera: Noctuidae). Eublemma gayneri (Rothschild) (Lepidoptera: Noctuidae) can be considered to be a ‘value unknown’ species in the wild. Because of their sporadic occurrence, Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae) and Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) are considered to be of lesser importance than H. armigera and A. loreyi, but should also be considered during pre-and post-release monitoring.