| dc.description.abstract | The aim of the experiment was to study the effect of Aedes aegypti larval density and dryness on survival and pathogenicity of Aspergillus niger. The effect of larval density on survival and pathogenicity of A. niger was studied using instar III of A. aegypti larvae, whereas the effect of dryness was studied on A. aegypti egg. The survival and pathogenicity test of A. niger on A. aegypti larvae were carried out in unsterilized tap water. The fungi used was A. niger carrying gfp gene as a marker. The treatment of larval density used were 10, 50, 100, 150, and 200 larvae. The number and age of eggs used were 200 and a week-old, respectively. Parameters measured were number of A. niger colony, larval mortality, and eggs hatching. The result showed that fungal survival that indicated by number of colony reduced from 1x108 spores in first day to 225 spores in the second day and the reduction continued until 6 days after incubation to 30 spores. At 7 days incubation, the colony increased to 40 spores. A. niger had high pathogenicity on larvae and eggs of A. aegypti. The mortality of larvae at all treatments started at 3 days after inoculation. The mortality at 3 days after inoculation were 6.7, 9.3, 13.0, 18.0, and 21.5% at 10, 50, 100, 150, and 200 larval, respectively. The mortality increased at 14 days after inoculation. The values were 33.3, 38.7, 52.0, 54.4, and 58.5% at 10, 50, 100, 150, and 200 larval density treatment, respectively. The A. niger had high pathogenicity on A. aegypti eggs. All of eggs tested did not hatch after inoculated by A. niger and incubated for 14 days. | en |
