Van der Linde, T. C. de K.Brown, Deodanda2017-11-072017-11-072001-07http://hdl.handle.net/11660/7443English: Aedes aegypti (Linnaeus) was reported for the first time in 1996 in the Bloemfonteinregion. Due to the fact that this was not the normal distribution area of this species, the main objective of the study was to do research on the bio-ecology of Ae. aegypti in order to determine whether it can get established in the Free State. Trapping of both adult and immature mosquitoes were done at two weekly intervals from 1996 - 1998. This was done at three localities in the Bloemfontein urban area viz the "Dam van Trane", Valley of Seven Dams and the Pony Club Dam, in the region where this species was recorded for the first time. The aim of these trappings was to get a general idea of the species diversity, relative abundance and seasonal fluctuations of the mosquitoes in this area. Ten mosquito species were collected during the study. Aedes juppi McIntosh was the most abundant species, accounting for 36,6% of the total catch followed by Culex theileri Theobald (32,4%) and Aedes aegypti which constituted only 0,5% of the total catch. The seasonal fluctuation and abundance of all the species that were caught, were analyzed and correlated with meteorological parameters such as temperature, rainfall and relative humidity. From these is was concluded that no parameter can be singled out, but that a combination of all the above parameters playa role in the occurrence and distribution of the mosquito species.An Ae. aegypti laboratory colony was established. Results originating from various experiments contributed to the sucessful colonization of this species. Adults were kept in electronically controlled rearing rooms at a temperature of 25°C ± 1°C and a relative humidity of70% ± 2%, with a day-night cycle of 12 hours light and 12 hours darkness including a dawn and a dusk period of one hour respectively. For carbohydrate feeding, adults were fed on 7% sugar water and pigeons were used for bloodmeals. Oviposition occurred on white strips of paper towel which were placed in black plastic containers filled with 300ml of 0,02M NaCl-solution and a small amount of larval food. These containers were placed inside the mosquito cages and left for three days.Eggs had to be dried for at least four days at 25°C and a relative humidity of >68% before they were submerged in the water for hatching to occur successfully. Larvae were held in shallow pans filled with O,02M NaCI-solution and kept in the rearing rooms at 25°C_ They were fed a mixture of brewer's yeast and an infant cereal. Carbohydrates play an important role in the bloodfeeding, ovipositioning and survival of the females. Females that were fed on cane sugar as carbohydrate source, performed significantly better in taking a bloodmeal and producing eggs than females that fed only on fruit. The fruit-fed females also had a significantly lower survival. If Ae. aegypti females have regular access to bloodmeals, they are capable of surviving on protein from the blood. Ae. aegypti larvae are able to take up NaCI from diluted solutions (O,OIM - O,02M) and are able to survive and develop in distilled water. NaCl-solutions above O,08M had a negative impact on larval development and at concentrations above O,12M NaCl survival is negatively influenced Successful development and survival of the immature stages occurred at temperatures between 15°C and 35°C. The optimum development temperature was 30°C. A constant temperature of 35°C however, had a negative influence on the physical size of the adults. The results obtained from the laboratory studies were used in an attempt to explain the occurrence of Ae. aegypti in the Free State and to try and determine whether this species will be able to establish itself permanently in the Free State.Afrikaans: Aedes aegypti (Linnaeus) is in 1996 vir die eerste keer in die Bloemfontein-omgewing gerapporteer. Aangesien dit buite die normale verspreidingsgebied van hierdie spesie was, was die hoofdoel van die studie om die bio-ekologie van Ae. aegypti na te vors om vas te stelof dit moontlik suksesvol in die Vrystaat kan vestig. Tweeweeklikse versamelings van beide volwasse en onvolwasse muskiete is vanaf 1996 tot 1998 uitgevoer. Dit is by drie lokaliteite in die Bloemfontein-stedelike gebied, nl. by die Dam van Trane, die Vallei van Sewe Damme en die Ponieklubdam, in die omgewing waar hierdie spesie die eerste keer gevind is, uitgevoer. Die doel van hierdie versamelings was om net 'n algemene indruk van die spesieverskeidenheid, relatiewe volopheid en seisoenale fluktuasies van muskiete in hierdie gebied te kry. Tien muskietspesies is gedurende die studie versamel. Aedes juppi McIntosh was die dominante spesie en het 36,6% van die totale vangste uitgemaak gevolg deur Culex theileri Theobald (32,4%), met Aedes aegypti wat slegs 0,5% van die totale vangste uitgemaak het. Die seisoenale verspreiding en volopheid van al die spesies wat versamel is, is met weerkundige data o.a. temperatuur, reënval en relatiewe humiditeit gekorreleer. Die gevolgtrekking was dat geen enkele faktor uitgesonder kon word nie, maar dat 'n kombinasie van hierdie faktore 'n rol speel in die voorkoms en verspreiding van die muskietspesies.'n Ae. aegypti-kolonie is in die laboratorium gevestig. Resultate vanuit verskeie eksperimente het bygedra tot die suksesvolle kolonisering van hierdie spesie. Volwassenes is in elektronies beheerde teelkamers aangehou by 'n temperatuur van 25°C ± 1°C, 'n relatiewe humiditeit van 70% ± 2% en 'n dag-nagsiklus van 12 ure lig en 12 ure donkerte, wat 'n oggend- en aandskemering van een uur elk ingesluit het. Vir koolhidraatvoeding het volwassenes op 'n 7% suikeroplossing gevoed en duiwe is as bloedmaalbron gebruik. Eierlegging het plaasgevind op stroke wit handdoekpapier wat in swart plastiekhouers, gevul met 300rnl 0,02M NaCl-oplossing en 'n klein bietjie larwevoedsel, geplaas is en vir drie dae in die muskiethokke gelaat is. Eiers moes eers vir ten minste vier dae by 'n temperatuur van 25DC en 'n relatiewe humiditeit van >68% gedroog word, voordat dit weer in water geplaas is en uitbroeiing suksesvol kon plaasvind. Larwes is in vlak panne, gevul met O,02M NaCI-oplossing, in die teelkamers by 25DC aangehou. Hulle voedsel het bestaan uit 'n mengsel van brouersgis en babagraankos. Koolhidrate speel 'n belangrike rol in die bloedvoeding-, eierlegging en oorlewing van die wyfies. Wyfies wat rietsuiker as koolhidraatbron ontvang het, het in vergelyking met wyfies wat slegs op vrugte gevoed het, betekenisvol beter bloed gevoed en eiers geproduseer. Oorlewing by vrugtegevoede wyfies was ook swakker. Indien hulle gereeld toegang het tot 'n bloedrnaai, is Ae. aegypti wyfies in staat om slegs op proteïene, afkomstig vanuit die bloed, te oorleef.Ae. aegypti larwes is in staat om NaCI vanuit uiters verdunde oplossings (O,OlM - O,02M) op te neem en kan suksesvol in gedistilleerde water oorleef en ontwikkel. NaCl-oplossings bokant O,08M het 'n nadelige invloed op larwalegroei en by NaCloplossings hoër as O,12M word oorlewing negatiefbeïnvloed. Suksesvolle ontwikkeling en oorlewing van die onvolwasse stadia het by temperature tussen 15DC en 35°C voorgekom. Die optimum ontwikkelingstemperatuur was 30DC. 'n Konstante temperatuur van 35DC het egter 'n negatiewe invloed op die fisiese grootte van die volwassenes gehad. Die resultate wat vanuit die laboratoriumeksperimente verkry is, is gebruik om die voorkoms van Ae. aegypti in die Vrystaat te probeer verklaar en vas te stel of hierdie spesie permanent in die Vrystaat gevestig kan raak.afMosquitoes -- South Africa -- Free StateDissertation (M.Sc. (Zoology and Entomology))--University of the Free State, 2001DissertationUniversity of the Free State