The Ephemeroidea or burrowing mayflies are a superfamily of the Ephemeroptera (mayflies) with a worldwide distribution. Recent decades have seen a sharp decline in their abundance globally. Literature reviews of the past 20 years have shown this superfamily to be well represented on the Mooi River, KwaZulu-Natal- five species (Eatonica schoutedeni, Ephemera mooiana, Afromera natalensis, Afroplocia sampsoni and Ephoron savignyi) were recorded during the 20th century. However recent fieldwork failed to confirm this professed diversity, recording only two species (Afromera natalensis and Ephoron savignyi). This work critically re-examined all of the literature relating to the Ephemeroidea of Africa (in the context of the five species recorded from KwaZuluNatal) published in Africa and Europe (as well as many publications from the rest of the world) during the 19th and 20th century. It was found that a number of oversights were made in much of this literature that have become assimilated into the understanding of the taxonomy and ecology of this group. Amongst these, it was found that the synonymisation of three species of Ephoron ( = Polymitarcys-Polymitarcys savignyi, P. capensis and P. temerata) in the 1920s was weakly justified. To clarify problems in the published record relating to the five species recorded from KwaZulu-Natal, some of the most important museum holdings in Europe and South Africa were re-examined. Two previously unknown collections of Ephemera sp. were found in European museums. One of these collections was made in West Africa, undermining theories that Ephemera sp. are only found in cold waters. This research confirmed that the records for Eatonica schoutedeni in KwaZulu-Natal are probably spurious, the result of misidentification. This work presents a review of the publications relating to each of the species of the Ephemeroidea recorded from KwaZulu-Natal. Lists of synonyms are provided. Descriptions from literature and museum specimens are given. The known distribution and biology of each is presented. The current status of the Ephemeroidea of KwaZulu-Natal are discussed and a new key to the species of Kwazulu-Natal is presented. In order to assess the purported diversity of Ephemeroidea in the rivers of the KwaZulu-Natal midlands, extensive fieldwork was carried out the Mooi River and on other tributaries of the Tugela and Mgeni rivers from 1998 to 2000. This investigation failed to reveal four of the five species indicated in the literature. The sole species that was found, Ephoron savignyi was abundant in some areas of the Mooi and Karkloof Rivers. This apparent drop in diversity may be because the sampling effort carried out from 1998 to 2000 was too limited in time and space to gather specimens of all the species resident in the river, or because environmental changes in the region in the last 50 years have resulted in the extirpation of any or all of the remaining four species. It is concluded that the records of Eatonica schoutedeni from KwaZulu-Natal are spurious; Ephemera mooiana is either not the only species in the genus Ephemera on the continent of Africa, or has a substantially wider distribution than previously thought; Afromera natalensis and Afroplocia sampsoni may be present on the rivers of KwaZulu-Natal but have not been found during this research; Ephoron spp. are abundant in KwaZulu-Natal, but further research is required to confirm that the species in South Africa are the same as those originally recorded from the type locality, Egypt. / Thesis (M.Sc.)-University of KwaZulu- Natal, Pietermaritzburg, 2004.

This study comprises an examination of over 4000 male specimens, including nearly all type material, a detailed study of the genitalia, and a key to the majority of the species of Tricholabiodes Radoszkowski. Thirty species and subspecies are redescribed and 22 new species described. The 22 newly described species are: T. acer, T. alveolus, T. brothersi, T. concavus, T. convexus, T. denticidatus, T. disgregus, T. femoralis, T. ferrugineus, T. indistinctus, T. inornatus, T. longicarinatus, T. liiridus, T. parallel™, T. paulocellatiis, T. petiolatus, T. protitberans, T. recurvatus, T. sinuatus, T. thisboides, T. tortilis and T. trochantalis. Tricholabiodes semisthataeformis Bischoff and T. pathzii Invrea are synonyms of T. stigmaticus Bischoff and T. pallidicornis Bischoff, respectively. Phenograms and principal component plots were derived to clarify species status, make decisions on species limits and used to determine the morphological similarity between the species. The phenetic analysis was used only as a tool, and not a final product. For the determination of species limits, which included an analysis of 447 specimens, the continuous quantitative and coded characters were analysed separately. Forty-three continuous quantitative characters were analysed either as standardized measurements (against mesosoma length) or as ratios (32), since it was not possible, even via gap coding, to code these characters. Scatterplots and a phenogram from the principal components and cluster analyses respectively, are presented. Size and shape were not particularly helpful characters in determining species limits. One hundred and twenty five coded characters were analysed in a cluster analysis and part of the final phenogram is presented. For the determination of morphological similarity between the species, a hypothetical specimen, typical of each species, was derived. Again, one hundred and twenty-five coded characters were analysed in a cluster analysis and the final phenogram is presented. Representatives from each of the species and subspecies were examined with respect to 93 coded characters. The character states were polarised using the outgroup Dasylabroides Andre. Where Tricholabiodes had all states occurring in Dasylabroides, and the primitive state could not be identified, these characters, and their states, were considered for the entire tribe, and the sister tribe of Dasylabrini, Sphaeropthalmini, was taken as the outgroup. The cladograms were constructed with the software Hennig86. The most variable characters were eliminated from the analysis. Selection of the cladogram representing the most likely phylogeny of the genus was based on parsimony, resolution of the tree, character placement on the tree, comparison of the tree with weighted/unweighted consensus trees and biogeography. The phylogeny presented, which is to be regarded only as a hypothesis, suggests that Tricholabiodes underwent nine separate radiations. The southern African species are divided into two lineages: the first divergence stems from the base of the tree while the more recent lineage stems from the apex. Evidence suggests that the genus arose in central Africa, spreading south (twice) into southern Africa, north into North Africa, west across central North Africa and east into southeastern Asia. The study has also shown that the majority of the species are restricted in their distribution, with none of Palaearctic species occurring in southern Africa, and vice versa. It is hypothesised that the present distribution of the genus is partially restricted by dispersal ability and climate. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1998.

Monthly sampling of 71 laboratory nests, each with a pair of adults, revealed that eggs and first-instar larvae were observed in the third month, minor workers in the fourth month and minor soldiers in the seventh month. Mortality of the pairs was high, with only five pairs surviving over the 10 month period. Laboratory nests did not develop further than the copularium. Excavation of 30 nests, of differing sizes, revealed that five were juvenile nests, consisting of only thin shelving with a few flattened fungus combs scattered throughout, and all, even the youngest nest (3 to 5 years), had a small mound. The queens from these young nests were small and had white pleural and intersegmental membranes. Twenty mature nests had a medium to large mound with large air passages and a medium to large hive with a well defined fungus garden containing large fungus combs. The queens from these nests were medium- to large sized, with white to brown pleural and intersegmental membranes. The remaining five nests had mounds often covered with grass, and a hive that contained less fungus comb than expected. The mounds of these nests were classified using their sandy pediment or crumbly texture. These were senescent or declining nests. The queens had pale brown pleural membranes and brown intersegmental membranes, and were often flaccid. The royal cell was commonly found in the middle to upper part of the nursery (20 nests), but sometimes was found at the edge of the nursery (five nests). The royal cells of five nests were not found or had been destroyed during excavation. The "youngest" mound was one to two years old and the "oldest" was more than 25 years old. The youngest queen was estimated to be three to five years old and the oldest queen more than 27 years. The nest seems to remain subterranean for two or less years before producing a mound. Thirteen nests were vigorous and five declining. The remaining 12 nests could not be classified as no fungus comb was collected from the nests. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.

Insecticide resistance in malaria vector mosquitoes reduces the efficacy of insecticide in killing and can therefore cause a major problem for malaria vector control by insecticides. In Mozambique, pyrethroid resistance in Anopheles funestus was first detected in December 1999 in the southern corner of Maputo Province. Since then, various collections have been made at selected sites throughout the country and WHO standard susceptibility tests and biochemical assays were conducted to determine the susceptibility status and the major resistance mechanisms, in the Fl generation of field collected mosquitoes. Three malaria vector species: Anopheles funestus s.s., Anopheles gambiae s.s. and Anopheles arabiensis were identified in this study by Polymerase Chain Reaction (PCR) and their distributions plotted. The susceptibility data indicate that the Anopheles funestus s.s population in southern Mozambique is widely resistant to pyrethroid and with low levels of carbamate resistance evident at six localities. No resistance to organophosphate and DDT was observed at any study sites. Biochemical tests indicate the presence of an altered acetlylcholinesterase in all collection localities with the exception of Massinga district. Elevated esterase activity with substrate a-naphthyl acetate were detect in Boane with a probable role in organophosphate resistance. Elevated GST were detected in Boane, Moamba and Catembe. Very low levels monooxygenase titres were registered in all the localities in Mozambique, which suggest that this resistance mechanism is not operating in these areas. Pyrethroid resistance in the Anopheles gambiae complex was detected only in Anopheles arabiensis from one locality. No resistant to other groups of insecticide were observed. Altered acetlylcholinesterases were registered in all collection localities and in both species: Anopheles gambiae s.s. and Anopheles arabiensis. Elevated esterase with substrate a-naphthyl acetate were detected in Anopheles arabiensis at only one locality. Elevated GSTs were detected at all localities and in both species. The implications of the findings for malaria vector control in Mozambique are discussed. / Thesis (M.Sc.)-University of Natal, Durban, 2003.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: In surveys carried out on poultry farms in the Western Cape Province, South Africa, the larvae of the flies Musca domestica L., Fannia canicularis (L.) and Leptocera sp. were found to be numerous. The majority of M domestica larvae and the mite Proctolaelaps sp. were recovered from manure with temperatures between 20 and 26°C while the larvae of F. canicularis and Leptocera sp. were mostly found between 14 and 22°C. Predominant predatory arthropods in the manure were the histerid Carcinops pumilio (Erichson), the staphylinid Philonthus sordidus (Gravenhorst) and the mite Macrocheles muscaedomesticae (Scopoli). These had a manure temperature tolerance of between 12 and 31°C. Macrocheles muscaedomesticae and P. sordidus preferred fresh manure, whilst C pumilio preferred aged manure. Therefore these two predators could complement one another in integrated pest management programmes. From a study of the vertical cross-sectional profile of the manure cone it was clear that the larvae of the prey species M domestica and F. canicularis and predator P. sordidus distinctly occupy the crest of the manure cone. The succession of arthropods in accumulating poultry manure and the effect of manure height on their numbers was studied. The prey species M domestica and F. canicularis were the first colonizers followed by the predators P. sordidus and M muscaedomesticae. Carcinops pumilio was a late colonizer. The numbers of M domestica and F. canicularis larvae were negatively correlated with the increase in manure height whilst the numbers of the predators C pumilio and M muscaedomesticae were positively correlated with this. The total developmental time of C pumilio from egg to adult emergence at 30°C was 20.5 days. Two larval instars were recorded. The immature stages sustained about 50% mortality before adult emergence. Carcinops pumilio adults can live up to 130 days at 30°C and had a Type I survivorship curve. The intrinsic rate of natural increase (rm) was 0.064943 and net reproduction rate (Rs) was 20.191.The rate of oviposition was directly proportional to body size and weight. Increase in density had a dampening effect on fecundity and led to an increase in developmental time. Thus density will be a critical factor in any mass rearing programme for this predator of fly larvae. In addition, an increase in density stimulated the dispersal of C. pumilio. A crowding level of 50 C. pumilio adults per 200ml container resulted in the least dispersal which did not exceed 2.5% per day, compared with up to 24.0% at a crowding level of 400. The predation rate of flies by C. pumilio in the laboratory decreased with an increase in predator density, but increased with an increase in starvation. Starvation had no effect on predation rate of M muscaedomesticae. A technique exploiting Drosophila melanogaster Meig. as a source of prey was successfully developed for rearing C. pumilio, which could be of commercial value. Drosophila melanogaster appeared to be an ideal candidate as a source of prey for mass rearing C. pumilio due to its short developmental time of about ten days. It is also inexpensive and easy to breed, and has a very high biotic potential. Carcinops pumilio that were fed on artificial diet had a prolonged developmental time and increase in weight, and laid fewer eggs than those fed on natural diet. C. pumilio completed its development on the artificial diet and both the F, and F2 generations fed on an artificial diet were able to lay eggs. This could be the first step towards finding an artificial diet that would allow continuous rearing of C. pumilio and their availability at all times for utilization in the biological control of houseflies. / AFRIKAANSE OPSOMMING: In opnames wat op pluimveeplase in die Westelike Kaapprovinsie, Suid-Afrika uitgevoer is, is gevind dat die vliegsoorte Musca damestica L., Fannia canicularis (L.) en Leptacera sp. volop is. Die meeste van die M. damestica larwes en die myt Practalaelaps sp. is versamel in hoendermis met temperature tussen 20 en 26°C en die larwes van Ficanicularis en Leptacera tussen 14 en 22°C. Die volopste predatoriese arthropode in die mis was die histerid Carcinaps pumilia Erichson, die staphylinid Philanthus sardidus (Gravenhorst) en die myt Machrascheles muscaedamesticae (Scopoli). Hulle temperatuurtoleransie in die mis was tussen 12 en 31°C. Machrasceles muscaedamesticae en P. sardidus het vars mis verkies, terwyl C. pumilio voorkeur aan ouer mis gegee het. Gevolglik behoort hierdie twee predatore mekaar te komplementeer in programme van ge-integreerde plaagbestuur. In Studie van die vertikale deursnee-profiel van die miskeel het duidelik getoon dat die prooispesies M. damestica en en F canicularis en die predator P. sardidus in die kroon van die miskeel voorkom. Die opeenvolging van die arthropode in die ophopende hoendermis en die invloed van mishoogte op hulle getalle is bestudeer. Die prooispesies M damestica en F canicularis was die eerste koloniseerders, gevolg deur die predatore P. sardidus en M muscaedamesticae. Carcinaps pumilia was In laat koloniseerder. Die getalle van die larwes van M damestica en F. canicularis was negatief gekorreleer met die toename in mishoogte terwyl die getalle van die predartore C. pumilia en M. muscaedamesticae positief daarmee gekorreleer was. Die totale ontwikkelingstyd van C. pumilia van eier tot die volwassene se verskyning was 20.5 dae by 30°C. Twee larwale instars is gevind. Die onvolwasse stadia het 50% mortaliteit ondergaan voor die verskyning van die volwassenes. Die volwassenes van C. pumilia kan tot 130 dae lank by 30°C lewe en het In Tipe 1 oorlewingskurwe gehad. Die intrinsieke tempo van natuurlike toename (rm) was 0.064943 en die netto reproduksietempo (Rs) 20.191. Die tempo van eierlegging was in direkte verhouding tot die liggaamsgrootte en massa. Toename in digtheid het 'n onderdrukkende effek op vrugbaarheid gehad en tot 'n toename in ontwikkelingstyd gelei. Digtheid sal dus 'n kritieke faktor wees III emge program van massateling vir hierdie predator van vlieglarwes. Daarmee saam het 'n toename in digtheid die verspreiding van C. pumilio gestimuleer. By 'n digtheid van 50 C. pumilio volwassenes per houer het die verspreiding nie 2.5% oorskrei nie, in vergelyking met tot 24.0% by 'n dightheid van 400. Die predasietempo van vliee deur C. pumilio in die laboratorium het afgeneem met 'n toename in predatordigtheid, maar toegeneem met 'n toename in verhongering. Verhongering het nie 'n invloed gehad op die predasietempo van M. muscaedomesticae nie. 'n Tegniek met Drosophila melanogaster Meig. as bron van prooi in die teling van C pumilio is suksesvol ontwikkel en dit kan van kommersiele waarde wees. Dit blyk dat D. melanogaster ideaal kan wees as 'n bron van prooi in die massateling van Cpumilio vanwee sy kort ontwikkkelingstyd van ongeveer tien dae. Die spesies is ook goedkoop en maklik om te teel, en het 'n baie hoe biotiese potensiaal.Care inops pumilio wat op 'n kunsmatige dieet gevoed het, het 'n verlengde ontwikkelingstyd en gewigstoename gehad, en het minder eiers gele as die wat op 'n natuurlike dieet gevoed het. C. pumilio het sy lewensloop op die kunsmatige dieet voltooi en beide die FJ en F2 generasies wat op die kunsmatige dieet gevoed het, was in staat om eiers te Ie. Dit kan die eerste stap wees in 'n poging om 'n kunsmatige dieet te vind wat dit sal moontlik maak om C. pumilio aaneenlopend te teel sodat dit deurlopend beskikbaar kan wees vir gebruik in die biologiese beheer van huisvliee,

The endemic landbirds of the Seychelles granitic islands have suffered considerable losses due to predation by introduced rats and cats and extensive habitat destruction. With less than 100 individuals, the Critically Endangered Magpie Robin Copsychus sechellarum Newton, faces the greatest risk of extinction. Translocations to three predator-free islands, Aride, Cousin and Cousine, have provided valuable opportunities for gaining insights into the ecology of the species. Of particular interest are links between the Magpie Robin, endemic skinks Mabvya spp., ground-living invertebrates and seabird colonies. Magpie Robin faecal pellet and skink gut content analysis demonstrated a high degree of dietary overlap between the species. A widespread exotic cockroach Pycnoscelus indicus was the favourite prey item for each species. However, behavioural observations and a dietary choice experiment indicated that there is no significant competition for food during the main seabird breeding season. Invertebrate sampling on Cousine identified 52 species which were available in all habitat types currently in use or those considered suitable for the Magpie Robin. Seabird and skink density counts on Cousine demonstrated the considerable magnitude of vertebrate organic food also available. Invertebrate sampling results on Cousin and Cousine were used to determine territory quality and the carrying capacity of each island for the Magpie Robin. While most seabirds are not breeding, skink survival depends on invertebrate abundance. M. wrightii weight declined throughout this period but that of M. sechellensis remained fairly stable. The data were insufficient to conclude that inter-specific competition for food exists between M. sechellensis and the Magpie Robin during this period. Further expansion of the Magpie Robin population depends on eradicating mammalian predators from other islands and maximising the potential carrying capacities of those already supporting the species. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

Pyrimethamine efficacy was investigated in vitro on the blood asexual stages, the sexual stages and exflagellation in Plasmodium falciparum. Gametocytogenesis was stimulated following the standard methods on five isolates of Plasmodium falciparum. From these five isolates, RSA 2, 3 and 5 produced gametocytes which reached maturity within seven days and the gametocytes were able to exflagellate. Isolate MW2 produced young gametocytes which disappeared within ten days. NF54 produced mature gametocytes which lasted for 24 hours only. There were no statistically significant differences between the static and the synchronization methods of gametocyte stimulation for any of the isolates. The effect of pyrimethamine was investigated by adding a known concentration of the drug (For RSA 2, MW2 and NF54, l00nmol/ℓ; RSA 3 and 5, 3000nmol/ℓ pyrimethamine) to the culture medium for seven days during gametocyte stimulation. The results of this investigation show that there was gametocytocidal activity on the isolates that were used and pyrimethamine also had a schizontocidal action on NF54 and the young gametocytes of this isolate were destroyed by the drug. At concentrations which were inhibitory to asexual parasites, the drug had a sporontocidal effect on isolate RSA 2 but not on isolate RSA 5. The pyrimethamine MIC values for asexual parasites ranged from 300nmol/ℓ to > 3000nmol/ℓ (RSA 2 and 5 were not inhibited at 3000nmol/ℓ ). These results are consistent with those found in previous studies when pyrimethamine resistance was first detected in South Africa. The chloroquine MICs indicate a good correlation with the results obtained from previous drug sensitivity tests for all the isolates examined using both the 48-hour in vitro test and isotope incorporation for growth assessment. The isobolograms constructed to determine relationship between chloroquine and pyrimethamine indicated no synergism for isolates RSA 2 and 5, but the Σ relative IC[50]s indicated a weak synergism. Both the isobolograms and the Σ relative IC[50]s for the isolates RSA 6, 9 and 14 indicated an antagonistic action between chloroquine and pyrimethamine. The results obtained from this study have important implications for malaria control in South Africa. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1995.

Stegodyphus mimosarum Pavesi,1883 and S. dumicola Pocock, 1898 are two species of philopatric, inbred, permanently communal, non-territorial spiders that co-occur in parts of South Africa. The patchiness of colony distribution, limited dispersal capabilities and the observation of periodic, but rare mass dispersal events raised interest in factors influencing dispersal. The aim of this project was firstly, to determine which factors influence the spiders' readiness to leave a colony (two laboratory experiments), and secondly, to map nest dispersion in Weenen Nature Reserve, Kwa-Zulu Natal, and to use this to explain nest distribution. The first experiment assessed whether group size and variance in access to resources influenced the decision to disperse. Four colony sizes (8, 16,32 and 64) of S. mimosarum were established under a proportional feeding regime. I expected more spiders to leave larger colonies due to intra-group competition. However, there was no significant increase in the number of spiders leaving with increasing group size. Significantly more spiders left a colony during spring and when spiders were large. In the second experiment, I assessed whether the mean amount of food available, in liberally fed or starved colonies influenced the decision to disperse. Five colonies were fed daily on an abundance of prey items and five were starved. I expected more spiders to leave the starved colonies. However, a significant number of spiders left colonies where food was abundant. During a field survey nests were tagged within 40 plots of 50 m radius, and randomly. Retreat dimensions, height above ground, nest position, nearest neighbouring nests, and species were recorded. Nest status was tracked over six months to three years. I confirmed that nest height above ground was significantly higher for S. mimosarum. The two species differed in retreat volume and nearest neighbour distances. Most nests occurred on the northern aspect of trees. Few nests survived beyond three years, although many new nests were established. Access to resources influenced the decision to disperse. However, only well-fed (larger) spiders had the resources to relocate. Patchy nest distribution could be a consequence of nest site selection, short distance dispersal by budding and bridging, and long distance dispersal by ballooning. / Thesis (M.Sc.)-University of Natal, Durban, 2002.

Thesis (PhD) -- Stellenbosch University, 1989. / ENGLISH ABSTRACT: Arthropod communities of five proteaceous species viz. Protea repens. P. neriifolia. P.cynaroides, Leucospermum cordifolium and Leucadendron /aureolum were studied. A faunal list of the insects was compiled according to the feeding guilds of insects. Six phytophagous guilds were recognized: flower visitors, thrips, endophages, ectophages, sap-suckers, and ants. The guild composition, species packing and seasonal distribution for the free-IMng insects, spiders and other arthropods were investigated on the different plant species. The ants, flower visitors and sap-sucking species found on the plant species, were very similar, but the number of leaf chewing species common to all the plant species was low, suggesting that some species were monophagous. Insect abundance increased during the wet winter months when the plants were in flower. Of the total number of herbivores collected, flower visitors represented 69,5%, leaf feeders 14,5% and sap-suckers 16,1 %. The chewers constituted 60,1% of the total herbivore. biomass. Leaf damage increased with age ; young leaves were practically free of herbivore damage, while older leaves were stm acceptable as food. The degree of insect damage differed amongst the plant species varying from 2% to 15%. The following leaf characteristics were investigated to determine the factors involved in defence against insect herbivory : total phenolic content, protein precipitating ability, cyanogenesis, nitrogen content, leaf toughness, woodiness and fibre content lt appears that the plant species use different mechanisms to protect their leaves. The infructescences of Protea repens were exploited by the larvae of four Coleoptera and four Lepidoptera species. The community structure of these phytophagous insects was determined largely by negative interactions. Various strategies are followed (e.g. niche segregation in time and space) to lessen interspecific competition. / AFRIKAANSE OPSOMMING: 'n Studie van die arthropoocl gemeenskap op vyf proteasoorte, naamlik Protea repens. P. neriffolia. P. cynaroides. Leucospennum cordffolium en Leucadendron laureolum is gedoen. 'n Faunalys van insekte volgens hul voedingsgDdes is saamgestel. Die insekte is in ses fitofage gDdes verdeel naamlik blombesoekers, blaaspootjies, endovoeders, ektovoeders, sapsuiers en miere. Die samestelling van die gDdes, spesie-rangskikking en seisoenale verspreiding is bepaal vir die vrylewende insekte, spinnekoppe en ander arthropode. Die miere, blombesoekers en sapsuierspesies wat op die plantsoorte gevind is, is byna dieselfde, maar verslalle in die blaarvoederspesies is gevind wat 'n aanduiding is dat sommige spesies monofaag mag wees. Gedurende die nat wintermaande toon die insekgetalle 'n toename. Blombesoekers verteenwoordig 69,5%, blaarvoeders 14,5% en sapsuiers 16,1% van die aantal insekherbivore wat versamel is. Die kouers vorm 60,1% van die totale herbivoor biomassa Soos die blare verouder, neem die skade op die blare toe; jong blare toon byna geen skade nie, terwyl ouer blare steeds geskik is vir insekvoedsel. Die insekskade op die blare wissel by die verslallende plante tussen 2% en 15%. Om te bepaal watter blaareienskappe moontlik 'n rol kan speel in blaarverdediging teen insekte is die volgende ondersoek: totale fenoliese inhoud, die vermoe om proteiene te presipiteer, sianogenese. stikstofinhoud, blaartaaiheid, houtagtigheid en veselinhoud. Dit wil voorkom asof die plante verskillende meganismes gebruik om die blare te beskerm. Saadkoppe van Protea repens word deur vier Coleoptera en vier Lepidoptera spesies benut Die gemeenskapstruktuur van die boarders word tot 'n groat mate bepaal deur negatiewe interaksies. Verskeie strategiee word gevolg (bv. nissegregasie in ~ en ruimte) om kompetisie tussen spesies te verminder.

Thesis (MScConsEcol)--Stellenbosch University, 1970. / AFRIKAANSE OPSOMMING: Verskeie aspekte van die biologie van die wingerdfilloksera is bestudeer. Die ondergrondse lewensiklus is in spesiale teelbakke waargeneem en die ontwikkelingstydperk van elke stadium word afsonderlik aangegee. Dit is bepaal dat die ontwikkeling van n eier tot n volwasse radicicolae-wyfie gemiddeld 22 dae duur en dat die ontwikkeling van n eier tot n alata gemiddeld 30 dae duur. Die leeftyd en tydperk van eierlegging van n volwasse wyfie asook die aantal eiers wat geproduseer word, word aangegee. Verskillende gegewens wat in verband met oorwintering verkry is, word bespreek. Die tyd van voorkoms van die verskillende stadia van die radicicolae-siklus in die natuur, is bepaal. Die aktiewe · stadium duur vanaf September tot Mei, die oorwinterende stadium vanaf April tot Oktober en nimfe kom voor vanaf November tot April. Met die gegewens verkry, is die aantal generasies per jaar teoreties bepaal. Filloksera is tot op n diepte van 1.2 m in die grond gevind. Daar is vasgestel dat verskillende grondtipes n invloed op die fillokserabesmetting het. Die besmetting neem af soos die persentasie fyn plus medium sandinhoud van n grond styg. Opnames het getoon dat 95% van die wingerde met Jacquez as onderstok in die Stellenbosch-area besmet is en dat ongeveer 25% van alle wingerde in die Olifantsrivier-besproeiingsgebied besmet is. Met behulp van sekere vangapparate is alatae vir die eerste keer in Suid-Afrika in die natuur versamel. Die leeftyd en eierproduksie van alatae en verskillende aspekte van die voorkoms van die galicolae-siklus word bespreek. Twee metodes is toegepas om morfologiese rasse van filloksera·te onderskei. Met behulp van een van die metodes kon verskille tussen die populasies van die twee geografies verskillende areas wat ondersoek is, aangetoon word. / ENGLISH ABSTRACT: None