Modifying an artificial diet for mass rearing mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), using locally available maize meal

Rini, Lulama Angela (2003-03)

Thesis (MSc)--University of Stellenbosch, 2003.

Thesis

ENGLISH ABSTRACT: The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is well-known as a destructive pest of fruit worldwide. Various control methods have been used against this insect. The sterile insect technique (SIT) is used as an important and successful technological method for controlling or eradicating this pest in many countries. A key factor to successfully apply SIT is dependent on the availability of efficient and economical rearing methods. Artificial insect diets with low cost bulking agents have been of interest to many researchers. The present study investigated the use of locally available maize meal as a bulking agent in such diets. Maize meal is used for human consumption (in South Africa) and contains small amounts of protein. This makes the reduction of imported torula yeast as an ingredient of the diet and source of protein possible, thereby reducing the cost of the diet. The larval development of the Medfly reared on artificial diets was studied in small and large-scale tests. The effect of the diets on larval production was evaluated using pupal recovery, pupal weight, flight ability, sex ratio, fecundity and egg fertility. The results of the small-scale tests showed that the diet containing maize meal could be used to produce Medfly more economically than the standard Krige diet used by the ARC Infruitec-Nietvoorbij Research Institute at Stellenbosch. However, in large-scale tests the ingredients quantities of the diets used were not the same as those of small scale-tests. The cost of the modified larval diet was not reduced in large-scale tests. This was ascribed to the number of eggs used in the tests to produce one million of fruit flies. The maize meal with reduced number of eggs require more diet to produce one million flies therefore, making it more expensive and less viable. When similar amounts of eggs were used, the diet appears to be a suitable alternative as the result obtained was almost similar to those of the Krige diet.

AFRIKAANSE OPSOMMING: Die Mediterreens vrugtevlieg ("Medfly"), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is wêreldwyd 'n skadelike plaag. Die steriele insek tegniek (SIT) het in baie lande 'n belangrike en suksesvolle manier geword om die plaag te beheer en uit te roei. Die belangrikste voorvereiste vir die suksesvolle toepassing van SIT is die beskikbaarheid van doeltreffende en ekonomiese teelmetodes. Meeste navorsers is geïntereseerd in kunsmatige diëte met 'n goedkoop vulstof. Hierdie studie is ontwerp om die gebruik van plaaslik beskikbare mieliemeel as vulstof te ondersoek. In Suid-Afrika word dit vir menslike gebruik aangewend en bevat klein hoeveelhede proteïene wat 'n vermindering van die ingevoerde torula gis moontlik kan maak, en sodoende die koste van die dieët kan verminder. Die ontwikkeling van Medfly larwes op kunsmatige diëte is bestudeer In kleinskaalse en grootskaalse eksperimente. Die invloed van die diëte op larwale produksie is evalueer deur gebruik te maak van van papie-ontwikkeling, papie-gewig, vliegvermoë, geslagsverhouding, volwasse voortplantingsvermoë en eiervrugbaarheid. Die resultate van die kleinskaalse toetse het aangetoon dat die mieliemeel dieët gebruik kan word om Medfly meer ekonomies as met die standaard Krige dieët, wat in die ARC Infruitec-Nietvoorbij navorsings instituut by Stellenbosch gebruik word, te teel. By die grootskaalse toetse was die koste nie laer nie. Dit word toegeskryf aan die aantal eiers wat gebruik is om 'n miljoen vlieë te produseer. Die mieliemeel dieët met 'n verminderde aantal eiers benodig meer dieët om 'n miljoen vlieë te produseer, wat dit duurder en minder lewensvatbaar maak. Wanneer soortgelyke hoeveelhede eiers gebruik was, het dit geblyk dat die dieët 'n opsie is, want die resultaat was soortgelyk aan dié van die Krige dieët.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/53500
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